endangered species research paper outline

This website uses cookies to ensure you get the best experience. Learn more about DOAJ’s privacy policy.

Hide this message

You are using an outdated browser. Please upgrade your browser to improve your experience and security.

The Directory of Open Access Journals

Quick search, endangered species research esr.

1863-5407 (Print)  / 1613-4796 (Online)

• ISSN Portal

Publishing with this journal

The journal charges up to:

as publication fees (article processing charges or APCs).

There is a waiver policy for these charges.

Look up the journal's:

• Aims & scope
• Instructions for authors
• Editorial Board
• Anonymous peer review

Expect on average 31 weeks from submission to publication.

Best practice

This journal began publishing in open access in 2015 . What does DOAJ define as Open Accesss?

This journal uses a CC BY license.

Attribution

→ Look up their open access statement and their license terms .

The author does not retain unrestricted copyrights and publishing rights.

Deposit policy with:

• Sherpa/Romeo

Permanent article identifier:

Journal metadata

Publisher Inter-Research , Germany Other organisation Inter-Research Manuscripts accepted in English

LCC subjects Look up the Library of Congress Classification Outline Science: Zoology Science: Botany Keywords conservation management endangered species endangered habitats

WeChat QR code

Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

• View all journals
• Explore content
• About the journal
• Publish with us
• Sign up for alerts

Collection  03 May 2022

Editor's choice: threatened species

Biodiversity is in crisis and according to some estimates tens of thousands of species disappear every year. Many others are on the verge of extinction. We can only halt this decline if we have a fundamental understanding of threatened species and are able to put in place effective conservation plans to guarantee their survival.

Following the IUCN Red List categories, this collection brings together some of the latest research on the biology and conservation efforts of a wide variety of threatened species from around the world.

Critically Endangered

State-space models reveal a continuing elephant poaching problem in most of Africa

• Scott Schlossberg
• Michael J. Chase
• Keith Lindsay

Enhanced, coordinated conservation efforts required to avoid extinction of critically endangered Eastern Pacific leatherback turtles

• The Laúd OPO Network

The conservation value of admixed phenotypes in a critically endangered species complex

• Keren R. Sadanandan
• Gabriel W. Low
• Frank E. Rheindt

Molecular phylogeny of one extinct and two critically endangered Central Asian sturgeon species (genus Pseudoscaphirhynchus ) based on their mitochondrial genomes

• Artem V. Nedoluzhko
• Fedor S. Sharko
• Nikolai S. Mugue

First use of artificial canopy bridge by the world’s most critically endangered primate the Hainan gibbon Nomascus hainanus

• Bosco Pui Lok Chan
• Yik Fui Philip Lo

Wild Bornean orangutans experience muscle catabolism during episodes of fruit scarcity

• Caitlin A. O’Connell
• Andrea L. DiGiorgio
• Erin R. Vogel

Chimpanzees balance resources and risk in an anthropogenic landscape of fear

• Elena Bersacola
• Catherine M. Hill
• Kimberley J. Hockings

Fine-scale genetic structure in the critically endangered red-fronted macaw in the absence of geographic and ecological barriers

• Guillermo Blanco
• Francisco Morinha
• José L. Tella

Mapping silver eel migration routes in the North Sea

• Pieterjan Verhelst
• Jan Reubens
• David Righton

Genome-wide SNPs redefines species boundaries and conservation units in the freshwater mussel genus Cyprogenia of North America

• Kyung Seok Kim
• Kevin J. Roe

Defining priority areas for blue whale conservation and investigating overlap with vessel traffic in Chilean Patagonia, using a fast-fitting movement model

• Luis Bedriñana-Romano
• Rodrigo Hucke-Gaete
• Daniel M. Palacios

High resolution biologging of breaching by the world’s second largest shark species

• Jessica L. Rudd
• Owen M. Exeter
• Lucy A. Hawkes

Deep genetic structure at a small spatial scale in the endangered land snail Xerocrassa montserratensis

• Cristina Català
• Vicenç Bros
• Marta Pascual

Shrub and vegetation cover predict resource selection use by an endangered species of desert lizard

• Christopher J. Lortie
• Jenna Braun
• H. Scott Butterfield

The endocast of the Night Parrot ( Pezoporus occidentalis ) reveals insights into its sensory ecology and the evolution of nocturnality in birds

• Andrew N. Iwaniuk
• Aubrey R. Keirnan
• Vera Weisbecker

Uncovering unique plasticity in life history of an endangered centenarian fish

• Martin J. Hamel
• Jonathan J. Spurgeon
• Mark A. Pegg

Effects of both climate change and human water demand on a highly threatened damselfly

• Rassim Khelifa
• Hayat Mahdjoub
• Michael J. Samways

Changes in diving behaviour and habitat use of provisioned whale sharks: implications for management

• Gonzalo Araujo
• Jessica Labaja
• Alessandro Ponzo

Protecting nursery areas without fisheries management is not enough to conserve the most endangered parrotfish of the Atlantic Ocean

• Natalia C. Roos
• Guilherme O. Longo
• Adriana R. Carvalho

Heterogeneity in patterns of helminth infections across populations of mountain gorillas ( Gorilla beringei beringei )

• Klara J. Petrželková
• Carine Uwamahoro
• David Modrý

Faecal DNA to the rescue: Shotgun sequencing of non-invasive samples reveals two subspecies of Southeast Asian primates to be Critically Endangered species

• Dewi Imelda Roesma

Oil palm cultivation critically affects sociality in a threatened Malaysian primate

• Anna Holzner
• Krishna N. Balasubramaniam
• Anja Widdig

Environmental DNA detection tracks established seasonal occurrence of blacktip sharks ( Carcharhinus limbatus ) in a semi-enclosed subtropical bay

• Bautisse D. Postaire
• Judith Bakker
• Demian D. Chapman

Slow life history leaves endangered snake vulnerable to illegal collecting

• Chris J. Jolly
• Brenton Von Takach
• Jonathan K. Webb

Free-roaming dogs limit habitat use of giant pandas in nature reserves

• Ramana Callan
• Jacob R. Owens
• Zhihe Zhang

Seasonal influence on the bathymetric distribution of an endangered fish within a marine protected area

Identifying priority conservation areas in a Saharan environment by highlighting the endangered Cuvier’s Gazelle as a flagship species

• F. Javier Herrera-Sánchez
• Jose María Gil-Sánchez
• Teresa Abáigar

Temperature stress and disease drives the extirpation of the threatened pillar coral, Dendrogyra cylindrus , in southeast Florida

• Nicholas P. Jones
• Lystina Kabay
• David S. Gilliam

Defining intraspecific conservation units in the endemic Cuban Rock Iguanas ( Cyclura nubila nubila )

• Kyle J. Shaney
• L. Grisell Diaz-Ramirez
• Ella Vázquez-Domínguez

Habitat preferences of Southern Ground-hornbills in the Kruger National Park: implications for future conservation measures

• Leigh Combrink
• Hendrik J. Combrink
• Colleen T. Downs

Quick links

• Explore articles by subject
• Guide to authors
• Editorial policies

REPORTS, ARTICLES AND RESEARCH PAPERS

Endangered species.

    • Paving the Road to Extinction: Congress’ Expanded Assault on Endangered Species Through Appropriations Poison-Pill Riders .Kurose, S., and Hartl, B., Center for Biological Diversity, January 2024.     • Recovery of the Grizzly Bear at the Intersection of Law and Science . Greenwald, N. August 2023.     • No Refuge: How America’s National Wildlife Refuges Are Needlessly Sprayed With Nearly Half a Million Pounds of Pesticides Each Year . Connor, H. May 2018.     • Mexico's 10 Most Iconic Endangered Species . Olivera, A. April 2018.      • A Wall in the Wild: The Disastrous Impacts of Trump's Border Wall on Wildlife . Greenwald, N., Segee, B., Curry, T. and Bradley, C. May 2017.      • Pollinators in Peril: A Systematic Status Review of North American and Hawaiian Native Bees . Kopec, K., Center for biological Diversity, February 2017.      • Removing the Walls to Recovery: Top 10 Species Priorities for a New Administration. Endangered Species Coalition (including the Center). December 2016.      • Shortchanged: Funding Needed to Save America's Most Endangered Species . Greenwald, N., Hartl, , B., Mehrhoff, L., Pang, J. December 2016.      • Taxa, Petitioning Agency, and Lawsuits Affect Time Spent Awaiting Listing Under the US Endangered Species Act . Greenwald, N., Kesler, D., Puckett, E. Biological Conservation . September 2016.      • Fishing Down Nutrients on Coral Reefs . Allgeier, J.E., Valdivia,A., Cox, C. & Layman, C.A. Nature Communications . August 2016.      • A Wild Success: A Systematic Review of Bird Recovery Under the Endangered Species Act . Suckling, K., Mehrhoff, L., 2016. Beam, R. & Hartl, B. June 2016.      • Poisoned Waters: How Cyanide Fishing and the Aquarium Trade Are Devastating Coral Reefs and Tropical Fish . Center for Biological Diversity & For the Fishes. June 2016.     • Lethal Loophole: How the Obama Administration Is Increasingly Allowing Special Interests to Endanger Rare Wildlife . Sanerib, T., Elkins, C., and Greenwald, N. February 2016.     • Biodiversity on the Brink: The Role of “Assisted Migration" in Managing Endangered Species Threatened With Rising Seas . Lopez, J. Harvard Environmental Law Review Vol. 39. 2015.     • Politics of Extinction: The Unprecedented Republican Attack on Endangered Species and the Endangered Species Act . Pand, J., and Greenwald, N. July 2015.     • Runaway Risks: Oil Trains and the Government's Failure to Protect People, Wildlife and the Environments . Margolis, J., 2015.     • Sea-Level Rise and Species Survival along the Florida Coast . Lopez, J. 2014.     • Collision Course: The Government's Failing System for Protecting Florida Manatees from Deadly Boat Strikes . Center for Biological Diversity. September 2014.      • Nourished by Wildfire: The Ecological Benefits of the Rim Fire and the Threat of Salvage Logging . Center for Biological Diversity and John Muir Projejct, January 2014.      • Deadly Waters: How Rising Seas Threaten 233 Endangered Species . Center for Biological Diversity. 2013.     • In Harm's Way: How the U.S. State Department and U.S. Fish and Wildlife Service Have Ignored the Dangers of the Keystone XL Pipeline to Endangered Species . Burd, L., Greenwald, N., & Bradley, C., 2013.     • Dying for Protection: The 10 Most Vulnerable, Least Protected Amphibians and Reptiles in the United States . Adkins Giese, C. 2013.     • On Thin Ice: After Five Years on the Endangered Species List, Polar Bears Still Face a Troubling Future . Center for Biological Diversity. 2013.     • A Poor Track Record, but a Chance to Excel . Snape, W., 2013. The Environmental FORUM   Environmental Law Institute, www.eli.org ) 30(1): 53.     • Can A Multi-Species Habitat Conservation Plan Save San Diego's Vulnerable Vernal Pool Species? Buse, J., 2012. Golden Gate University Environmental Law Journal 6(1): 52-80.     • On Time, On Target: How the Endangered Species Act Is Saving America's Wildlife . Suckling, K., Greenwald, N., Curry, T. 2012.     • Protecting Rare Amphibians Under the U.S. Endangered Species Act . Adkins Giese, C., FrogLog (May 2012): 21-23.     • White-nose Syndrome Headed to a Cave Near You . Matteson, M. Desert Report (June 2011): 6-7.     • Impact of Dunes Sagebrush Lizard on Oil and Gas Activities in New Mexico . Lininger, J. & Bradley, C., 2011.    • Assessing Protection for Imperiled Species of Nevada, U.S.A.: Are Species Slipping Through the Cracks of Existing Protections? Bradley, C. & Greenwald, N., 2008.     • Not Too Late to Save the Polar Bear: A Rapid Action Plan to Address the Arctic Meltdown . Siegel, K., Cummings, B., Moritz, A. & Nowicki, B., 2007.     • Status of the Bald Eagle in the Lower 48 States and the District of Columbia: 1963-2007 . Suckling, K. & Hodges, W., 2007.     • The Bureaucratically Imperiled Mexican Wolf . Povilitis, A., Parsons, D.R., Robinson, M.J., & Becker, C.D., 2006.     • A Review of Northern Goshawk Habitat Selection in the Home Range and Implications for Forest Management in the Western United States . Greenwald, D. N., Crocker-Bedford, C., Broberg, l., & Suckling, K., 2005.     • Suitable Habitat for Jaguars in New Mexico . Robinson, M., Bradley, C., Boyd, J., 2005.     • Impacts of the 2003 Southern California Wildfires on Four Species Listed as Threatened or Endangered Under the Federal Endangered Species Act: Quino Checkerspot Butterfly, Mountain Yellow-legged Frog, Coastal California Gnatcatcher, Least Bell's Vireo . Bond, M. & Bradley, C., 2003.     • A Conservation Alternative for the Management of the Four Southern California National Forests (Los Padres, Angeles, San Bernardino, Cleveland) . Penrod, K., et al., 2002.     • Analysis of Compliance by U.S. Forest Service Southwestern Region with Incidental Take Statements Issued by the U.S. Fish and Wildlife Service in Three Biological Opinions of 1999 . Taylor, M. 2001.

ENDANGERED SPECIES ACT

   • Taxa, Petitioning Agency, and Lawsuits Affect Time Spent Awaiting Listing Under the US Endangered Species Act . Greenwald, N., Kesler, D., Puckett, E. Biological Conservation . September 2016.     • A Wild Success: A Systematic Review of Bird Recovery Under the Endangered Species Act . Suckling, K., Mehrhoff, L., Beam, R. & Hartl, B. June 2016.     • Saving Species and Wild Spaces: 10 Extraordinary Places Saved by the Endangered Species Act , Pang, J. & Hartl, B. May 2016.     • Politics of Extinction: The Unprecedented Republican Attack on Endangered Species and the Endangered Species Act . Pang, J., and Greenwald, N. July 2015.     • A Different Perspective on the Endangered Species Act at 40 Responding to Damien M. Schiff . Buse, J., 2015. University of California, Davis 38(1): 145-166.     • Making Room for Wolf Recovery: The Case for Maintaining Endangered Species Act Protections for America's Wolves . Weiss, A., Greenwald, N. & Bradey, C. Center for Biological Diversity, November 2014.     • A Wild Success: American Voices on the Endangered Species Act at 40 . Center for Biological Diversity, Endangered Species Coalition, Defenders of Wildlife, February 2014.     • On Time, On Target: How the Endangered Species Act Is Saving America's Wildlife . Suckling, K., Greenwald, N., Curry, T., 2012.     • A Future for All: A Blueprint for Strengthening the Endangered Species Act . 2011.     • Effects on Species' Conservation of Reinterpreting the Phrase “Significant Portion of its Range” in the U.S. Endangered Species Act . Greenwald, N., 2009. Conservation Biology 23(6): 1375-1377.     • State Endangered Species Acts . In Baur, D.C. & Irvin, W.R. (eds.), Endangered Species Act: Law, Policy, and Perspectives , second edition. American Bar Association. George, S. & Snape, W., 2010.     • Politicizing Extinction: The Bush Administration's Dangerous Approach to Endangered Wildlife . Greenwald, N., 2007.     • Measuring the Success of the Endangered Species Act, Recovery Trends in the Northeastern United States . Suckling, K.F., 2006.     • Factors Affecting the Rate and Taxonomy of Species Listings under the US Endangered Species Act . In Gobel, D, Scott, M.J. & Davis, F.W. (eds.), The Endangered Species Act at Thirty: Renewing the Conservation Commitment . Island Press. Greenwald, D.N., Suckling, K.F. & Taylor, M.F.J., 2006.     • Critical Habitat and Recovery . In: Gobel, D., Scott, M.J. & Davis, F.W. (eds.), The Endangered Species Act at Thirty: Renewing the Conservation Commitmen t. Island Press. Suckling, K.F. & Taylor, M.F.J., 2006.     • The Listing Record . In Gobel, D., Scott, M.J., & Davis, F.W. (eds.), The Endangered Species Act at Thirty: Renewing the Conservation Commitmen t. Island Press. Greenwald, D.N., K.F. Suckling and M.F.J. Taylor, 2006.      • Progress or Extinction? A Systematic Review of the U.S. Fish and Wildlife Service's Endangered Species Act Listing Program. 1974-2004 . Greenwald, D. N. & Suckling, K. F., 2005     • The Effectiveness of the Endangered Species Act: A Quantitative Analysis . Taylor, M.F.J., Suckling, K.F. & Rachlinski, J.J., 2005. BioScience 55(4): 360-367.     • Extinction and the Endangered Species Act . Suckling, K., Nowicki, B. & Slack, R., 2004.     • A Review of the Bush Critical Habitat Record . 2003.     • Bush Administration Attacks Endangered Species Act .     • Safeguarding Citizen Rights Under the Endangered Species Act . Senatore, M., & Suckling, K., 2001.

BIODIVERSITY

    • Hidden In Plain Sight: California's Native Habitats Are Valuable Carbon Sinks . Yap, T., Prabhala, A., Anderson, I. Center for Biological Diversity. July 2023.     • Bullfrogs: A Trojan Horse for a Deadly Fungus? Yap, T., Koo, M., Ambrose, R., Vredenburg, V.T. Science Journal for Kids . October 2018.     • Mexico's 10 Most Iconic Endangered Species . Olivera, A. April 2018.     • A Multi-method Approach to Delineate and Validate Migratory Corridors . Bond, M., Bradley, C., Kiffner, C., Morrison, T., and Lee, D. Landscape Ecology . May 2017.    • Biodiversity on the Brink: The Role of “Assisted Migration" in Managing Endangered Species Threatened With Rising Seas . Lopez, J. Harvard Environmental Law Review Vol. 39. 2015.    • Nourished by Wildfire: The Ecological Benefits of the Rim Fire and the Threat of Salvage Logging . Center for Biological Diversity and John Muir Projejct, January 2014.    • Joining the Convention on Biological Diversity: A Legal and Scientific Overview of Why the United States Must Wake Up . Snape, B., 2010. Sustainable Development Law & Policy 10(3): 6-18.    • Highways to Hell: A Critical Examination of the Environmental Impacts of the Security and Prosperity Partnership . Lopez, J., 2009. [3 MB version]    • Rana Aurora (Northern Red-legged Frog) Egg Mass Disturbance. Curry, T. R., and Hayes, M. P., 2009. Herpetological Review 40(2): 208-209.    • Greenwashing Risks to Baby-boomers Abroad: An Assessment of Available Strategies to Address “Green” Marketing Misrepresentation to U.S. Retiree Real Estate Investors Overseas. 2009.    • Life History Diversity and Protection of the Southwestern Washington/Columbia River Distinct Population Segment of the Coastal Cutthroat Trout . Greenwald, N. & Mashuda, S., 2008.     • Predation on the Coastal Tailed Frog ( Ascaphus truei ) by a Shrew ( Sorex spp.) in Washington State . Lund, E., Hayes, M., Curry, T., Marsten, J. & Young, 2008. Northwestern Naturalist 89(3): 200-202.     • Assessing Protection for Imperiled Species of Nevada, U.S.A.: Are Species Slipping Through the Cracks of Existing Protections? Greenwald, N. & Bradley, C., 2008.     • Medicinal Plants at Risk — Nature's Pharmacy, Our Treasure Chest: Why We Must Preserve Our Natural Heritage . Roberson, E., 2008.     • Species of Concern of the Tillamook Rainforest and North Coast, Oregon . Greenwald, N. & Garty, A., 2007.     • The Bering Sea: A Biodiversity Assessment of Vertebrate Species . Greenwald, N., Callimanis, S., Garty, A. & Peters, E., 2006.     • Saving All the Parts: Protecting Species of Northwest Old-growth Forests . Greenwald, N. & Greason, S., 2004.     • Imperiled Western Trout and the Importance of Roadless Areas . 2001.     • A Conservation Alternative for the Management of the Four Southern California National Forests (Los Padres, Angeles, San Bernardino, Cleveland) . Penrod, K., et al., 2002.     • Principles of Wildlife Corridor Design . Bond, M., 2003.

    • A  Wall  of  Lights  Through the Wild: 1,800 Stadium Lights on Arizona Conservation Lands Threaten Wildlife . McSpadden, R., Jordahl, L., and Bradley, C. Center for Biological Diversity. June 2023.     • Hidden In Plain Sight: California's Native Habitats Are Valuable Carbon Sinks . Yap, T., Prabhala, A., Anderson, I. Center for Biological Diversity. July 2023.     • Deadpool Highway: How Interstate 11 Would Worsen Arizona’s Water Crisis . McSpadden, R., and Bradley, C. Center for Biological Diversity. May 2023.     • State of Utom River 2022: Challenges, Opportunities for Southern California’s Signature River . Center for Biological Diversity. August 2022.     • A Wall in the Wild: The Disastrous Impacts of Trump's Border Wall on Wildlife . Greenwald, N., Segee, B., Curry, T. and Bradley, C. May 2017.     • A Multi-Method Approach to Delineate and Validate Migratory Corridors . Bond, M., Bradley, C., Kiffner, C., Morrison, T., and Lee, D. Landscape Ecology . May 2017.     • Public Lands Enemies: 15 Federal Lawmakers Plotting to Seize, Destroy and Privatize America's Public Lands . Spivak, R. & Beam, R. March 2017.     • Runaway Risks: Oil Trains and the Government's Failure to Protect People, Wildlife and the Environments . Margolis, J., 2015.     • Nourished by Wildfire: The Ecological Benefits of the Rim Fire and the Threat of Salvage Logging . Center for Biological Diversity and John Muir Projejct, January 2014.     • Groups Join Together to Confront Water-rights Issue . Mrowka, R. Desert Report (June 2011): 2, 13.     • Saving Our National Legacy: The Future of America's Last Heritage Forests . Fink, M., Kassar, C., Matteson, M., and McKinnon, T., July 2009.     • America's Newest Fossil Beds National Monument: Tule Springs/Upper Las Vegas Wash . Mrowka, R. and Davis, L., 2009.     • Wild at Heart: Saving the Last of America's Backcountry . 2008.     • Imperiled Western Trout and the Importance of Roadless Areas . 2001.     • Protection and Conservation of Roadless Areas in the Southwest . Greenwald, N.     • A Conservation Alternative for the Management of the Four Southern California National Forests (Los Padres, Angeles, San Bernardino, Cleveland) . Penrod, K., et al., 2002.

CLIMATE CHANGE

   • Flight Path: A Trajectory for U.S. Aviation to Meet Global Climate Goals . Center for Biological Diversity. October 2020.    • From Bailout to Righting the Course: The Commonsense Action the United States Must Take to Address the Flood Crisis . Lopez, J. 2020.    • Stealing California's Future: How Monterey County's Dirty Oil Business Worsens the Climate Crisis . Center for Biological Diversity. September 2016.    • Throwing Shade: 10 Sunny States Blocking Distributed Solar Development . Greer, R. April 2016.    • Up in the Air: How Airplane Carbon Pollution Jeopardizes Global Climate Goals . Pardee, V. December 2015.    • Biodiversity on the Brink: The Role of “Assisted Migration" in Managing Endangered Species Threatened With Rising Seas . Lopez, J. Harvard Environmental Law Review Vol. 39. 2015.    • Grounded: The President's Power to Fight Climate Change, Protect Public Lands by Keeping Publicly Owned Fossil Fuels in the Ground . Saul, M., McKinnon, T., Spivak, R., 2015.    • What Happens When Species Move But Reserves Do Not? Creating Climate Adaptive Solutions to Climate Change . Whipps, N., 2015. Hastings Law Journal Vol. 66.    • Runaway Risks: Oil Trains and the Government's Failure to Protect People, Wildlife and the Environments . Margolis, J., 2015.    • The Potential Greenhouse Gas Emissions From U.S. Federal Fossil Fuels . Ecoshift Consulting, Center for Biological Diversity, Friends of the Earth. August 2015.    • Troubled Waters: Offshore Fracking's Threat to California's Ocean, Air and Seismic Stability . Center for Biological Diversity, 2014.    • On Shaky Ground: Fracking, Acidizing, and Increased Earthquake Risk in California . Earthworks, Center for Biological Diversity, Clean Water Action, 2014.    • Deadly Waters: How Rising Seas Threaten 233 Endangered Species . Center for Biological Diversity, 2013.    • The New Normal: Climate Change Victims in Post- Kiobel United States Federal Courts . Lopez, J., 2013. Charleston Law Review 8(1).    • Not Just a Number: Achieving a CO 2 Concentration of 350 ppm or Less to Avoid Catastrophic Climate Impacts. Center for Biological Diversity and 350.org, 2010.    • Extinction: It's Not Just for Polar Bears. A Center for Biological Diversity and Care for the Wild International report. Wolf, S., 2010.    • Yes, He Can: President Obama's Power to Make an International Climate Commitment Without Waiting for Congress . Bundy, K., Cummings, B., Pardee, V. & Siegel, K., 2009.    • 350 Reasons We Need to Get to 350: Species Threatened by Global Warming; An Interactive Installation by the Center for Biological Diversity . 2009.    • No Reason to Wait: Reducing Greenhouse Gas Emissions Through the Clean Air Act . Siegel, K., Snape, W., and Vespa, M., June 2009.    • Why 350? Climate Policy Must Aim to Stabilize Greenhouse Gases at the Level Necessary to Minimize the Risk of Catastrophic Outcomes . Vespa, M., 2009. Ecology Law Currents 36(1): 185-194. • Fuel to Burn: The Climate and Public Health Implications of Off-road Vehicle Pollution in California . Kassar, C. & Spitler, P., 2008.     • Not Too Late to Save the Polar Bear: A Rapid Action Plan to Address the Arctic Meltdown . Siegel, K., Cummings, B., Moritz, A. & Nowicki, B., 2007.     • The California Environmental Quality Act: On the Front Lines of California's Fight Against Global Warming . Siegel, K., Vespa, M. & Nowicki, B., 2007.

    • Powerless in the United States: How Utilities Drive Shutoffs and Energy Injustice . Center for Biological Diversity, March 2023.     • Rooftop-Solar Justice: Why Net Metering is Good for People and the Planet and Why Monopoly Utilities Want to Kill It . Crystal,. H., Lin, R., and Su, J., Center for Biological Diversity, Energy and Policy Institute, BailoutWatch, January 2023.    • Fueling Extinction: How Dirty Energy Drives Wildlife to the Brink . Endangered Species Coalition (incl. the Center for Biological Diversity), 2012.    • A Deadly Toll: The Gulf Oil Spill and the Unfolding Wildlife Disaster . 2011. Center for Biological Diversity.    • What We Should Learn From the BP Spill . Lopez, J., 2011. Environmental Law News 20 (1): 35.    • Too Much Oil for the Rubber Stamp: The Government's Role in the BP Oil Spill . Lopez, J., 2011.    • BP's Well Evaded Environmental Review: Categorical Exclusion Policy Remains Unchanged . Lopez, J., 2010. Ecology Law Currents 37 (93): 93-103.    • Corporate Profile of Salt River Project . Draffan, G., 2001.    • Ecological and Community Problems with Biomass-to-Energy . Schulke, T.

ENVIRONMENTAL HEALTH/POLLUTION

    • Collateral Damage: How Factory Farming Drives Upthe Use of Toxic Agricultural Pesticides . Center for Biological Diversity, World Animal Protection, 2022.     • Pesticides and Environmental Injustice in the USA: Root Causes, Current Regulatory Reinforcement and a Path Forward . Donley, N., Bullard, R., Economos, J., Figueroa, I., Lee, J., Liebman, A., Navarro Martinez, D., & Shafiei, F. BMC Public Health , April 2022.     • Toxic Hangover: How the EPA Is Approving New Products With Dangerous Pesticides It Committed to Phasing Out . Donley, N., Jan. 2020.     • A Menace to Monarchs: Drift-prone Dicamba Poses a Dangerous New Threat to Monarch Butterflies . Donley, N., March 2018.     • Toxic Concoctions: How the EPA Ignores the Dangers of Pesticide Cocktails . Donley, N., July 2016.     • Can't We Just All Get Along: Reconciling Pesticide Use and Species Protection . Lopez, J. 2015.     • Lost in the Mist: How Glyphosate Use Disproportionately Threatens California's Most Impoverished Counties . Center for Biological Diversity, 2015.       • Perdido en la niebla: Como El uso de glifosato desproporcionadamente amenaza los condados más pobres de California . Center for Biological Diversity, 2015.     • Dispersants: The Lesser of Two Evils or a Cure Worse Than the Disease? Kilduff, C. and Lopez, J., 2012. Ocean and Coastal Law Journal 16 (2): 375-394.     • Endocrine-disrupting Chemical Pollution: Why the EPA Should Regulate These Chemicals Under the Clean Water Act . Lopez, J., 2010. Sustainable Development Law & Policy 10(3): 19-23.     • Poisoning Our Imperiled Wildlife: San Francisco Bay Area Endangered Species at Risk from Pesticides . Miller, J., Miller, J., Beeland, T.D. & Bradley, C., 2006.     • Silent Spring Revisited: Pesticide Use and Endangered Species . Litmans, B. & Miller, J, 2004.

POPULATION AND SUSTAINABILITY

    • Alternative Economies: Uplifting Activities for a Sustainable Future . Dennings, K., Adoma, A.; 2023.     • At What Cost: Unraveling the Harms of the Fast Fashion Industry . Shedlock, K., Feldstein, S.; 2023.     • Too Hot for Knitwear: Climate Crisis, Biodiversity and Fashion Brands Using Woll and Synthetics . Feldstein, S., Hakansson, E.; 2023.     • Talking Trash: U.S. Perspectives on the Language of Waste Reduction . Dennings, K., Adoma, A.; 2023.     • Unwrapped: Perceptions of Winter Holiday Consumerism, Gift Giving and Waste . Dennings, K., Adoma, A; 2023.     • The Influence of Environmental Toxicity, Inequity and Capitalism on Reproductive Health . Dennings, K., Grossman, A; 2022.     • Gender and the Climate Crisis: Equitable Solutions for Climate Plans . Dennings, K., Baillie, S., and Baxter, C; 2022.     • Public Perceptions on Population: US Survey Results . Dennings, K., Baillie, S., Ricciardi, R. and Addo, A; 2022; Population and Sustainability 6(1): 1-23.     • Sheer Destruction: Wool, Fashion and the Biodiversity Crisis . Feldstein, S., Hakansson, E., Katcher, J., Vance, V.; 2021.     • Endangered Species Condoms: A Social Marketing Tool for Starting Conversations About Population . Baillie, S., Dennings, K. and Feldstein S.; 2020; Journal of Population and Sustainability 4(2): 31-44.     • Contraception and Consumption in the Age of Extinction: U.S. Survey Results . Dennings, K., 2020.     • Appetite for Change: A Policy Guide to Reducing Greenhouse Gas Emissions of U.S. Diets by 2030 . Feldstein, S., 2020.     • Catering to the Climate: How Earth-Friendly Menus at Events Can Help Save the Planet . Molidor, J., Emery., I., 2019.     • Towards a Psychology of the Food‐Energy‐Water Nexus: Costs and Opportunities . Dreyer, S.J., Kurz, T., Prosser, A.M.B., Abrash, A.W., Dennings, K., McNeill, I., Saber, D.A., Swim, J.K., 2019. Journal of Social Issues 76(1).     • Slow Road to Zero: A Report Card on U.S. Supermarkets’ Path to Zero Food Waste . Molidor, J., Feldstein, S., Figueiredo, J., 2019.     • Checked Out: How U.S. Supermarkets Fail to Make the Grade in Reducing Food Waste . Molidor, J., Feldstein, S., 2018.     • Wasting Biodiversity: Why Food Waste Needs to Be a Conservation Priority . Feldstein, S., 2017. Biodiversity 18 (2-3): 75-77.     • Habitat-Fed Food: Grass-fed Beef and Sustainable Solutions . Molidor, J., 2017. Biodiversity 18 (2-3): 78-81.

FIRE AND FOREST RESTORATION

    • Nourished by Wildfire: The Ecological Benefits of the Rim Fire and the Threat of Salvage Logging . Center for Biological Diversity and John Muir Projejct, January 2014.     • Influence of Pre-Fire Tree Mortality on Fire Severity in Conifer Forests of the San Bernardino Mountains, California , 2009. Bond, M., Lee, D. E., Bradley, C. & Hanson, T. Open Forest Science Journal 2:41-47.     • Impacts of the 2003 Southern California Wildfires on Four Species Listed as Threatened or Endangered Under the Federal Endangered Species Act: Quino Checkerspot Butterfly, Mountain Yellow-legged Frog, Coastal California Gnatcatcher, Least Bell's Vireo . Bond, M. & Bradley, C., 2003.     • Ecological Restoration of Southwestern Ponderosa Pine Ecosystems: A Broad Perspective . Allen, C.D., Savage, M., Falk, D.A., Suckling, K. F., Swetnam, T. W., Schulke, T., Stacey, P. B., Morgan, P., Hoffman, M. & Klingel, J. T., 2002. Ecological Applications 12(5): 1418-1433.     • Prelude to Catastrophe: Recent and Historic Land Management within the Rodeo-Chedeski Fire Area .     • Effectively Treating the Wildland-Urban Interface to Protect Houses and Communities from the Threat of Forest Fire . Nowicki, B., 2002.     • Protection and Conservation of Roadless Areas in the Southwest . Greenwald, N.     • An Ecologically Integrated Approach to Managing Dwarf Mistletoe (Arceuthobium) in Southwest Forests .  Pollock, Michael M., Ph. D.  Kieran Suckling, 1995.      • A Conservation Alternative for the Management of the Four Southern California National Forests (Los Padres, Angeles, San Bernardino, Cleveland) . Penrod, K., et al., 2002.     • Fire & Forest Ecosystem Health in the American Southwest . Suckling, K., 1996.

LIVESTOCK GRAZING

    • Costs and Consequences: The Real Price of Livestock Grazing on America's Public Lands . Glaser, C., Romaniello, C. & Moskowitz, K. (prepared for the Center for Biological Diversity), 2015.     • Assessing the Full Cost of the Federal Grazing Program . Moskowitz, K., & Romaniello, C., 2002.     • Ecological Restoration of Southwestern Ponderosa Pine Ecosystems: A Broad Perspective . Allen, C.D., Savage, M., Falk, D.A., Suckling, K.F., Swetnam, T.W., Schulke, T., Stacey, P.B., Morgan, P., Hoffman, M. & Klingel, J.T., 2002. Ecological Applications 12(5): 1418-1433.     • Cattle Grazing and the Loss of Biodiversity in the East Bay .      • Livestock Grazing, Fire Regimes, and Tree Densities: A Literature Review .

    • Frogs . In Bernheimer, K. (ed.), Brothers and Beasts: An Anthology of Men on Fairy Tales. Wayne State University Press. Suckling, K.F., 2007.     • Biodiversity, Linguistic Diversity and Identity — Toward an Ecology of Language in an Age of Extinction . Suckling, K., 2000. Langscape 17: 14-20.     • A House on Fire: Connecting the Biological and Linguistic Diversity Crises . 2002. Animal Law 6: 193-202.

Get the latest on our work for biodiversity and learn how to help in our free weekly e-newsletter.

The Center for Biological Diversity is a 501(c)(3) registered charitable organization. Tax ID: 27-3943866.

An official website of the United States government

The .gov means it’s official. Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

The site is secure. The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

• Publications
• Account settings

Preview improvements coming to the PMC website in October 2024. Learn More or Try it out now .

• Advanced Search
• Journal List

Extinction and the U.S. Endangered Species Act

Noah greenwald.

1 Center for Biological Diversity, Portland, OR, USA

Kieran F. Suckling

2 Center for Biological Diversity, Tucson, AZ, USA

Brett Hartl

3 Center for Biological Diversity, Washington, DC, USA

Loyal A. Mehrhoff

4 Center for Biological Diversity, Honolulu, HI, USA

Associated Data

The following information was supplied regarding data availability:

The raw data are available in a Supplementary File and include a complete list of the species we identified as extinct or possibly extinct along with all supporting information.

The U.S. Endangered Species Act is one of the strongest laws of any nation for preventing species extinction, but quantifying the Act’s effectiveness has proven difficult. To provide one measure of effectiveness, we identified listed species that have gone extinct and used previously developed methods to update an estimate of the number of species extinctions prevented by the Act. To date, only four species have been confirmed extinct with another 22 possibly extinct following protection. Another 71 listed species are extinct or possibly extinct, but were last seen before protections were enacted, meaning the Act’s protections never had the opportunity to save these species. In contrast, a total of 39 species have been fully recovered, including 23 in the last 10 years. We estimate the Endangered Species Act has prevented the extinction of roughly 291 species since passage in 1973, and has to date saved more than 99% of species under its protection.

Introduction

Passed in 1973, the U.S. Endangered Species Act (ESA) includes strong protections for listed threatened and endangered species and has helped stabilize and recover hundreds of listed species, such as the bald eagle and gray whale ( Taylor, Suckling & Rachlinski, 2005 ; Schwartz, 2008 ; Suckling et al., 2016 ). In part because of its strong protections, the ESA has engendered substantial opposition from industry lobby groups, who perceive the law as threatening their profits and have been effective in generating opposition to species protections among members of the U.S. Congress. One common refrain from opponents of the ESA in Congress and elsewhere is that the law is a failure because only 2% of listed species have been fully recovered and delisted ( Bishop, 2013 ).

The number of delistings, however, is a poor measure of the success of the ESA because most species have not been protected for sufficient time such that they would be expected to have recovered. Suckling et al. (2016) , for example, found that on average listed birds had been protected just 36 years, but their federal recovery plans estimated an average of 63 years for recovery. Short of recovery, a number of studies have found the ESA is effectively stabilizing or improving the status of species, using both biennial status assessments produced by the U.S. Fish and Wildlife Service for Congress and abundance trends ( Male & Bean, 2005 ; Taylor, Suckling & Rachlinski, 2005 ; Gibbs & Currie, 2012 ; Suckling et al., 2016 ).

In addition to recovering species, one of the primary purposes of the ESA is to prevent species extinction. Previous studies indicate the ESA has been successful in this regard ( McMillan & Wilcove, 1994 ; Scott et al., 2006 ). As of 2008, the ESA was estimated to have prevented the extinction of at least 227 species and the number of species delisted due to recovery outnumbered the number of species delisted for extinction by 14–7 ( Scott et al., 2006 ). In this study, we identified all ESA listed species that are extinct or possibly extinct to quantify the number of species for which ESA protections have failed and use these figures to update the estimated number of species extinctions prevented. This is the first study in over 20 years to compile data on extinction of ESA listed species, providing an important measure of one of the world’s strongest conservation laws ( McMillan & Wilcove, 1994 ).

To identify extinct or possibly extinct ESA listed species, we examined the status of all 1,747 (species, subspecies and distinct population segments) U.S. listed or formerly listed species, excluding species delisted based on a change in taxonomy or new information showing the original listing to have been erroneous. We determined species to be extinct or possibly extinct based on not being observed for at least 10 years, the occurrence of adequate surveys of their habitat, and presence of threats, such as destruction of habitat of the last known location or presence of invasive species known to eliminate the species.

To differentiate extinct and possibly extinct species we relied on determinations by the U.S. Fish and Wildlife Service, IUCN, species experts and other sources. In most cases, these determinations were qualitative rather quantitative. Species were considered extinct if surveys since the last observation were considered sufficient to conclude the species is highly likely to no longer exist, and possibly extinct if surveys were conducted after the last observation, but were not considered sufficient to conclude that extinction is highly likely ( Butchart, Stattersfield & Brooks, 2006 ; Scott et al., 2008 ).

Source information included 5-year reviews, listing rules and critical habitat designations by the U.S. Fish and Wildlife Service (for aquatic and terrestrial species) or NOAA Fisheries (for marine species), published and gray literature, personal communication with species experts and classifications and accounts by NatureServe, IUCN and the Hawaiian Plant Extinction Prevention program. For each species, we identified year of listing, year last seen, NatureServe and IUCN ranking, taxonomic group, and U.S. Fish and Wildlife Service region. For species last seen after listing, we also searched for abundance estimates at time of listing in order to give a sense of likelihood of survival regardless of ESA protection.

Following previously developed methods, we estimated the number of species extinctions prevented by the ESA by assuming that listed threatened and endangered species have a comparable extinction risk to IUCN endangered species, which was estimated as an average of 67% over 100 years ( Mace, 1995 ; Schwartz, 1999 ; Scott et al., 2006 ). We believe this estimate of extinction risk is conservative based on similarity of IUCN criteria to factors considered in ESA listings, observed low numbers for species at time of ESA listing and observed correspondence between ESA listed species and species classified as endangered or critically endangered by the IUCN ( Wilcove, McMillan & Winston, 1993 ; Wilcove & Master, 2005 ; Harris et al., 2012 ). Presumed extinction risk was then multiplied by the number of extant listed species and the proportion of a century in which species were protected by the ESA. Previous studies used the length of time the ESA has been in existence (1973-present) for the proportion of a century species have been protected ( Schwartz, 1999 ; Scott et al., 2006 ), but because many species have not been protected the entire 45 years the law has existed, we instead used the more conservative average length species were protected (25 years). This corresponds to the following formula:

We identified a total of 97 ESA listed species that are extinct (23) or possibly extinct (74). Of these, we found 71 extinct (19) or possibly extinct (52) species were last observed before they were listed under the ESA and thus are not relevant to determining the Act’s success in preventing extinction ( Table S1 ). These species were last seen an average of 24 years before protection was granted with a range of one to more than 80 years prior.

A total of 26 species were last seen after listing, of which four are confirmed extinct and 22 are possibly extinct ( Table S2 ). On average, these species were last seen 13 years after listing with a range of 2–23 years. We were able to find an abundance estimate at the time of listing for 19 of these species, ranging from one individual to more than 2,000 with an average of 272. In several cases, these estimates were based on extrapolations from very few sightings.

The distribution of extinct and possibly extinct species was non-random with 64 of the 97 species from Hawaii and other Pacific Islands, followed by 18 from the southeast ( Fig. 1 ). This was also the case for taxonomy. A total of 40 of the 97 species were mollusks dominated by Hawaiian tree snails and southeast mussels, followed by birds (18) and plants (17) ( Fig. 2 ).

Extinct or possibly extinct listed species by taxonomic group.

Extinct or possibly extinct listed species by U.S. Fish and Wildlife Service Region.

We identified several other species that have been missing for more than 10 years, but for which there has not been any effective surveys and thus classifying them as possibly extinct did not seem appropriate, including two Hawaiian yellow-faced bees ( Hylaeus facilis and Hylaeus hilaris ) (K. Magnacca, 2018, personal communication) and Fosberg’s love grass ( Eragrostis fosbergii ) ( U.S. Fish and Wildlife Service, 2011 ). If indeed extinct, all three were lost prior to protection under the ESA.

Including updated figures for number of listed species, time of protection and species extinctions, we estimate the ESA has prevented the extinction of roughly 291 species in its 45 year history. Based on the number of confirmed extinctions following listing, we further estimate that the ESA has to date prevented the extinction of more than 99% of species under its protection. To date, a total of 39 species have been delisted for recovery compared to four species that are extinct and 22 that are potentially extinct.

The few number of listed species that have gone extinct following protection combined with an estimated 291 species for which extinction was prevented demonstrate the ESA has achieved one of its core purposes—halting the loss of species. We will not attempt to catalog them here, but numerous individual examples provide further support for this conclusion. Well known species like the California condor ( Gymnogyps californianus ), black-footed ferret ( Mustela nigripes ) and Hawaiian monk seal ( Neomonachus schauinslandi ), as well as lesser known species like the yellowfin madtom ( Noturus flavipinnis ), are but a few of the species that likely would have been lost were it not for the ESA.

The madtom is a case in point. Wrongly presumed extinct when described in 1969, individual madtom were found in the Powell River in Tennessee and Copper Creek in Virginia and the species was protected under the ESA in 1977 ( U.S. Fish and Wildlife Service, 1977 ). Following protection, federal and state officials worked with a non-governmental organization, Conservation Fisheries Inc., to discover additional populations and repatriate the species to rivers and streams in its historic range and there are now populations of the yellowfin madtom in three different watersheds ( U.S. Fish and Wildlife Service, 2012a ). The history of the ESA is replete with similar such stories.

The distribution of extinct or possibly extinct listed species largely tracks those regions with the highest rates of species endangerment, including Hawaii and the Northern Mariana Islands with 64 of the 97 extinctions or possible extinctions, and the Southeast with 18 of the extinctions or possible extinctions, mostly freshwater species. The fragility of Hawaii’s endemic fauna to introduced species and habitat destruction and high degree of species imperilment is well recognized ( Duffy & Kraus, 2006 ). Similarly, the extinction and endangerment of freshwater fauna in the southeast is well documented ( Benz & Collins, 1997 ). To avoid further extinctions, these areas should be priorities for increased funding and effort.

Protection under the ESA came too late for the 71 species last seen prior to listing. It’s possible that some of these species survived undetected following listing, but we find this unlikely for most if not all of the species. It is very difficult to document extinction, but all of the species were the subject of survey both before and after listing, which is described in the listing rules and subsequent status surveys. In addition, the 71 species were last seen an average of 24 years prior to listing, providing a long window for detection prior to listing. If some of these species did survive after listing it was likely at very low numbers, such that recovery would have been difficult at best.

That these 71 species were lost before protections were applied clearly highlights the need to move quickly to protect species. Indeed, Suckling, Slack & Nowicki (2004) identified 42 species that went extinct while under consideration for protection. Since that analysis was completed, the U.S. Fish and Wildlife Service has determined five additional species did not qualify for protection because they were extinct, including the Tacoma pocket gopher ( Thomomys mazama tacomensis ), Tatum Cave beetle ( Pseudanophthalmus parvus ), Stephan’s riffle beetle ( Heterelmis stephani), beaverpond marstonia ( Marstonia castor ) and Ozark pyrg ( Marstonia ozarkensis ), meaning there are now 47 species that have gone extinct waiting for protection ( U.S. Fish and Wildlife Service, 2012b , 2016 , 2017 , 2018a ).

The U.S. Fish and Wildlife Service currently faces a backlog of more than 500 species that have been determined to potentially warrant protection, but which await a decision ( U.S. Fish and Wildlife Service, 2018b ). Under the ESA, decisions about protection for species are supposed to take 2 years, but on average it has taken the Fish and Wildlife Service 12 years ( Puckett, Kesler & Greenwald, 2016 ). Such lengthy wait times are certain to result in loss of further species and run counter to the purpose of the statute. This problem can be addressed by streamlining the Service’s process for listing species, which has become increasingly cumbersome, and by increasing funding for the listing program. For every species listed, the Service’s process includes review by upward of 20 people, including numerous individuals who have no specific knowledge of the species and in a number of cases are political appointees. We instead recommend that the Service adopt a process similar to scientific peer review, involving review by two to three qualified individuals.

The loss of 26 species after they were protected is indicative of conservation failure. This failure, however, in most cases cannot be wholly attributed to the ESA because most of these species were reduced to very low numbers by the time they were protected, making recovery difficult to impossible. Of the 19 species we could find an abundance estimate for at the time of listing, 13 had an estimated population fewer than 100 with eight having fewer than 10 individuals. Of the six other species, two Hawaiian birds, Oahu creeper ( Paroreomyza maculate ) and ‘O’u ( Psittirostra psittacea ) had estimated populations in the hundreds, but this was based on sightings of single individuals. Given the lack of further sightings and the presence of disease carrying mosquitoes throughout their habitat, these estimates were likely optimistic. The other four species, the dusky seaside sparrow ( Ammodramus maritimus nigrescens ), Morro Bay kangaroo rat ( Dipodomys heermanni morroensis ), pamakani ( Tetramolopium capillare ) and Curtis’ pearlymussel ( Epioblasma florentina curtisii ), had populations at the time of listing ranging from 100 to 3,000 individuals, but sufficient action was not taken to save them, making them true conservation failures.

At some level, all of the 97 ESA listed species that we identified as possibly extinct or extinct are conservation failures. For 42 of these species, the law itself was too late because they were last seen before the ESA was passed in 1973. But for others, there may have been time and we did not act quickly enough or dedicate sufficient resources to saving them. There are many examples of species both in the U.S. and internationally that have been successfully recovered even after dropping to very small numbers, but this can only occur with fast, effective action, resources and in many cases luck. The Mauritius kestrel ( Falco punctatus) , for example, was brought back from just two pairs ( Cade & Jones, 1993 ) and the Hawaiian plant extinction prevention program, which focuses on saving plants with fewer than 50 individuals, has rediscovered many species believed extinct, brought 177 species into cultivation, constructed fences to protect species from non-native predators and reintroduced many species into the wild ( Wood, 2012 , http://www.pepphi.org/ ).

The failure to provide sufficient resources for conservation of listed species, however, continues to the present. As many as 27 species of Oahu tree snail ( achatinella spp. ) are extinct or possibly extinct, yet expenditures for the species that still survive are inadequate to support minimal survey and captive propagation efforts. Likewise, the Hawaiian plant extinction prevention program, which has been so effective in saving species on the brink of extinction, is facing a budget cut of roughly 70% in 2019 ( http://www.pepphi.org/ ), which very likely could mean the extinction of dozens of plants that otherwise could be saved. Overall, Greenwald et al. (2016) estimate current recovery funding is roughly 3% of estimated recovery costs from federal recovery plans. We can save species from extinction, but it must be more of a priority for federal spending. Nevertheless, despite funding shortfalls and the tragedy of these species having gone extinct, the ESA has succeeded in preventing the extinction of the vast majority of listed species and in this regard is a success.

Management implications

Of the 97 species we identified as extinct or potentially extinct, only 11 have been delisted for extinction. Another 11 have been recommended for delisting due to extinction. The San Marcos gambusia ( Gambusia georgei ) could also be delisted since there is very little hope it survives. For the other 74 possibly extinct species, we recommend retaining protections in the hope that some will be rediscovered and because there is little cost in retaining listing.

Supplemental Information

Supplemental information 1.

Extinct or possibly extinct species broken out by whether last seen before or after protection was enacted, including relevant source data and literature cited.

Funding Statement

The authors received no funding for this work.

Additional Information and Declarations

All authors are employed by the Center for Biological Diversity which works to protect endangered species and their habitats.

Noah Greenwald conceived and designed the experiments, performed the experiments, analyzed the data, prepared figures and/or tables, authored or reviewed drafts of the paper, approved the final draft.

Kieran F. Suckling conceived and designed the experiments, performed the experiments, analyzed the data, authored or reviewed drafts of the paper, approved the final draft.

Brett Hartl conceived and designed the experiments, performed the experiments, analyzed the data, authored or reviewed drafts of the paper, approved the final draft.

Loyal A. Mehrhoff conceived and designed the experiments, performed the experiments, analyzed the data, authored or reviewed drafts of the paper, approved the final draft.

• Search Menu
• Sign in through your institution
• Advance articles
• Editor's Choice
• Special Collections
• Author Guidelines
• Submission Site
• Open Access
• Reasons to submit
• About BioScience
• Journals Career Network
• Editorial Board
• Advertising and Corporate Services
• Self-Archiving Policy
• Potentially Offensive Content
• Terms and Conditions
• Journals on Oxford Academic
• Books on Oxford Academic

Article Contents

Finding 1: listing enhances recovery over time, finding 2: critical habitat promotes species survival and recovery, finding 3: dedicated recovery plans assist species recovery, finding 4: multispecies recovery plans are less effective, finding 5: listing and regulation of take assist in species recovery, finding 6: esa protections do not favor animals over plants, finding 7: endangered species show less recovery than threatened species, the role of expenditures, conclusions, references cited.

• < Previous

The Effectiveness of the Endangered Species Act: A Quantitative Analysis

Martin F. J. Taylor ( [email protected] ) was a consulting conservation biologist with the Center for Biological Diversity, Tucson, AZ 85702, when this research was conducted. He is now the executive coordinator of the National Parks Association of Queensland, PO Box 1040, Milton Centre, Queensland 4064, Australia.

Kieran F. Suckling is policy director of the Center for Biological Diversity, and Jeffrey J. Rachlinski is a professor of law at Cornell Law School, Ithaca, NY 14853.

• Article contents
• Figures & tables
• Supplementary Data

Martin F. J. Taylor, Kieran F. Suckling, Jeffrey J. Rachlinski, The Effectiveness of the Endangered Species Act: A Quantitative Analysis, BioScience , Volume 55, Issue 4, April 2005, Pages 360–367, https://doi.org/10.1641/0006-3568(2005)055[0360:TEOTES]2.0.CO;2

• Permissions Icon Permissions

Population trends for 1095 species listed as threatened and endangered under the Endangered Species Act were correlated with the length of time the species were listed and the presence or absence of critical habitat and recovery plans. Species with critical habitat for two or more years were more than twice as likely to have an improving population trend in the late 1990s, and less than half as likely to be declining in the early 1990s, as species without. Species with dedicated recovery plans for two or more years were significantly more likely to be improving and less likely to be declining than species without. The proportion of species improving increased, and the proportion declining decreased, with increasing time listed throughout the 1990s, irrespective of critical habitat and recovery plans. On the basis of these results, we recommend increased funding for earlier listing of imperiled species and prompt provision of critical habitat and recovery plans.

Critics of the US Endangered Species Act (ESA; 16 U.S.C. §§ 1531–1540 [1988]) argue that the recovery of only 13 of some 1300 endangered species is an indication of failure ( Mann and Plummer 1995 , Pombo 2004 ). Others contend this is a poor measure of success, because few species have been protected under the ESA long enough to reach full recovery ( Doremus and Pagel 2001 ). The prevention of hundreds of extinctions ( NRC 1995 , Schwartz 1999 ) is an important accomplishment, but it does not indicate whether the ESA is effectively moving imperiled species toward recovery. As the ESA enters its 31st year, a comprehensive assessment of its role in species recovery is needed.

Data for such an analysis are available in biennial reports of the US Fish and Wildlife Service, or USFWS (1990 , 1992 , 1994 , 1999 , 2003 , 2004a ), and the National Marine Fisheries Service, or NMFS (1994 , 1996 , 2002 ). These reports score species as improving, stable, declining, or unknown for successive two-year periods. Previous studies used single reports to determine whether funding ( Miller et al. 2002 , Restani and Marzluff 2002 ), recovery plans ( Schultz and Gerber 2002 ), critical habitat ( Clark et al. 2002 ), and multiple factors ( Rachlinski 1997 ) were correlated with recovery trends. However, these two-year “snapshots”may not reliably reflect long-term population trends.

In this article, we combine trend data to examine correlations with the length of time that species were listed, their critical habitat, recovery plans, kingdom (plant or animal), and listing status (endangered or threatened). In a related paper ( Suckling and Taylor 2005 ), we review the statutory framework and present case studies to illustrate the mechanisms through which critical habitat designation affects species recovery.

The data from biennial reports were augmented and corrected to account for extinctions, delistings, and recovery. After correction, 1095 species were scored as declining, stable, or improving in at least one report. The data set is available from the authors on request. The agencies' trend scores are imprecise and subjective ( NRC 1995 , IG/USDOI 2003 ), but there is no reason to expect systematic, agency-wide bias. We assumed that the scores reflected actual population trends and that they were not influenced by knowledge of the presumed independent variables.

Preliminary analysis showed strong correlations between trends and the variables of interest in each biennial report; however, there were clear differences in the patterns of correlations between the early 1990s and later reports. Thus, we divided the data into an early period from 1990 to 1994 and a late period from 1997 to 2002, combining scores for these periods. We rejected conventional repeated-measures regression as a score-combining method, because a single unknown or missing score in any report removed a species from analysis. We also rejected simple score averaging, because it does not account for time directionality. For example, it gives the same trend score of “stable” to a species whose trend changes from declining to stable to improving in successive biennial reports as to a species moving in the other direction. Thus, we used time-weighted score averages. Numerical scores of 1 for improving, 0 for stable, and –1 for declining were assigned to each species. We then multiplied the most recent score by 1.5, the middle score by 1.0, and the oldest score by 0.5.A final score of “improving,”“declining,”or “stable”was assigned to each species if the weighted average was, respectively, 0.5 or greater, –0.5 or less, or between –0.5 and 0.5.

To deal with confoundments among the main independent variables, we used partial z statistics in logistic regression (using Intercooled Stata 8.0 software) in a way similar to the use of partial F statistics by Rachlinski (1997) . Because of the evident differences among trends for different groups of animals, higher taxonomic groups (as in figure 1 ) were used as a clustering variable, with robust standard errors.

Listing under the ESA provides species with an array of regulatory and nonregulatory benefits, including recovery plans, protection from unauthorized take, protection of critical habitat, scientific research, captive breeding, public education, and habitat restoration and acquisition. The longer species were listed, the more likely they were to be improving and the less likely to be declining (figure 2) , suggesting that ESA conservation measures act cumulatively over time. This correlation included any beneficial effect due to recovery plans and critical habitat, which were also more likely to be present for species listed for a longer time. We used logistic regression to ascertain how much of this effect was due to these distinct protections.

With limited exceptions, the ESA requires that critical habitat be designated for all listed species, encompassing all lands and waters “essential to the conservation of the species” (sec. 3[5][A]).“Conservation”is defined as all actions necessary to fully recover and delist species (sec. 3[3]). Federal agencies are prohibited from authorizing, funding, or carrying out actions that are likely to “destroy or adversely modify” critical habitats (sec. 7[a][2]). This prohibition also applies to state or private actions that require federal permits, such as Clean Water Act permits for significant development, mining, logging, or cattle operations and the approval of habitat conservation plans by the USFWS and NMFS.

In 1986, the Reagan administration promulgated regulations that defined “destruction or adverse modification” as an action that “appreciably diminishes the value of critical habitat for both the survival and recovery of a listed species” (Endangered and Threatened Wildlife and Plants: Interagency Cooperation, 50 C.F.R. part 402 [1986]). This definition has been controversial because it permits actions that reduce the potential for recovery as long as they do not also threaten a species' survival. On the basis of this definition, the US Department of the Interior asserts that critical habitat designation is redundant and unnecessary, as other aspects of the ESA more broadly prohibit jeopardizing the survival of a species ( USDOI 2003 ). The USFWS dramatically reduced the number of new critical habitat designations immediately after the regulations were issued ( Suckling and Taylor 2005 ).

In recent years, the 1986 regulations have been invalidated by numerous court rulings affirming that critical habitats must be managed to promote recovery, and not merely to avoid extinction (e.g., Conservation Council for Hawai'i et al. v. Bruce Babbitt et al., Civ. No. 97-00098 ACK [1998], Sierra Club v. US Fish and Wildlife Service and National Marine Fisheries Service, Civ. No. 00-30117 [2001], Gifford Pinchot Task Force et al. v. United States Fish and Wildlife Service, Civ. No. 03-35279 [2004]). In practice, land managers have often given significant protection to critical habitats despite official policy, as, for example, when the US Department of Energy established a preserve around critical habitat for Amsinckia grandiflora ; when the USDA Forest Service moved trails away from, and prohibited recreation within, critical habitat for Potentilla robbinsiana ; when the Forest Service removed domestic sheep from critical habitat for peninsular bighorn sheep; and when the Bureau of Land Management prohibited mining within critical habitat for Astragalus yoder-williamsii ( Suckling and Taylor 2005 ). The courts and USFWS biologists have also focused management decisions around critical habitat; for example, the USFWS required the Bureau of Land Management to remove sheep from critical habitat for the desert tortoise, and federal judges ordered cessation of livestock grazing in critical habitat for the palila, of ground-fish trawling in critical habitat for Steller's sea lion, and of lobster fishing in critical habitat for the monk seal ( Suckling and Taylor 2005 ).

Species with critical habitat for two or more years appeared to be more likely to be improving and less likely to be declining than species without (figure 3) . After using logistic regression to correct for the confounding effects of time listed and recovery plans, we found that species with critical habitat for two or more years were less than half as likely to be declining (i.e., more likely to be stable or improving) in the early period, and more than twice as likely to be improving in the late period, as species without such critical habitat (table 1) .

These results suggest that critical habitat assists species recovery, independent of the length of time listed and the presence of recovery plans. Rachlinski (1997) also found that species with critical habitat were 11 percent less likely to be declining and 14 percent more likely to be stable in the 1994 USFWS report. However, Rachlinski (1997) excluded 96 species (mollusks and species delisted or recovered before 1994), and thus the analyses are not entirely comparable. Another analysis of a small subset of data from the 1996 USFWS report showed a similar but statistically nonsignificant correlation, most likely due to small sample size and lack of control for confounding variables ( Clark et al. 2002 ).

The uneven rates of creation of critical habitats over time may have precluded the detection of negative correlations between critical habitat and declining trends in the late period. Critical habitat appeared to act primarily on a single cohort of species in both periods, moving them from declining to stable status in the early period and from stable to improving in the late period (table 1) . However, few critical habitats were designated from 1986 until the late 1990s ( Suckling and Taylor 2005 ), and so any cohort of declining species that entered the late period with recently designated critical habitat was probably too small to allow the detection of a negative correlation between critical habitat and declining trend in the late period.

We also considered that the observed correlation might be confounded by the effects of conservation actions unrelated to habitat protection, such as controls on hunting and disease. Accordingly, we reestimated regressions, including only species that were known to be habitat limited. We obtained data from Wilcove and colleagues (1998) , Clark and colleagues (2002) , and Miller and colleagues (2002) enabling 985 species to be classified as habitat limited or not. As these studies were biased toward species with recovery plans, we balanced the data by adding 77 species chosen at random from among species lacking recovery plans, which we could classify as habitat limited or not on the basis of their listing rules. Logistic regressions in which critical habitat was a significant factor were repeated on this habitat-limited subset of species, and critical habitat was found to remain highly significant as a factor (table 1) .

With limited exceptions, the ESA requires the development of recovery plans for all listed species (sec. 4[f][1]). Recovery plans recommend site-specific recovery actions, time frames for accomplishment, and criteria for judging whether recovery has been achieved.

As of 1 September 2004, 83 percent of the species listed by the USFWS and 32 percent of those listed by the NMFS had recovery plans ( Suckling and Taylor 2005 ). Implementation of recovery plans has been poor, however, with only 2 percent of USFWS-administered species having achieved more than 75 percent of their recovery objectives ( USFWS 2004b ). In addition, the plans have been criticized as vague, unlikely to abate threats, and lacking in biological rigor ( Schemske et al. 1994 , Tear et al. 1995 , Clark et al. 2002 , Lawler et al. 2002 , Schultz and Gerber 2002 , Stinchcombe et al. 2002 ). The criteria for determining whether species have recovered are often set too low ( Tear et al. 1993 , Foin et al. 1998 , Doremus and Pagel 2001 ). For many vertebrates, even the complete implementation of plans may not result in biological recovery ( Tear et al. 1995 ). Nonetheless, a positive correlation has been found between expenditures, as a percentage of funding recommended in recovery plans, and positive population trends ( Miller et al. 2002 ). Thus, the lack of implementation may be a more significant problem than the quality of the recovery plans. We also note that the development of recovery plans has become more rigorous in recent years ( Gerber and Hatch 2002 , Hoekstra et al. 2002 ).

Boersma and colleagues (2001) found that species with multispecies plans are more likely to be declining than species with dedicated plans. On the basis of these findings, we expected species with dedicated plans to be strongly associated with improving trends, and those associated with multispecies plans to be less so.

Species with recovery plans for two or more years appeared to be more likely to be improving and less likely to be declining than species without such plans. Species with dedicated or single-species plans appeared to fare better than those with multispecies plans (figure 3) . Using logistic regression to correct for the confounding effects of length of time listed and the presence of critical habitat, we found that species with dedicated recovery plans for two or more years were significantly more likely to be improving, and significantly less likely to be declining, in both early and late periods than species without such recovery plans (table 1) . Our results are consistent with Rachlinski's (1997) finding that recovery plans are positively associated with improving trend in the 1994 USFWS report.

Despite the many documented weaknesses of recovery plans, our results suggest that dedicated recovery plans have had a significant and consistent benefit for species recovery. However, there were no significant correlations between multi-species plans and population trends in either early or late periods. This does not mean that multispecies plans were ineffective, only that we failed to detect a correlation. The results are consistent with those of other studies finding relatively poor performance of multispecies plans—a matter of concern, since multispecies plans are becoming more common. Of plans developed since 2000, 73 percent were multispecies plans, compared with 55 percent of the plans developed in previous years. The reason for the lesser effectiveness of multi-species plans is unclear, but it has been attributed to a lack of management focus and consequent lack of sufficient attention to each species' needs ( Clark and Harvey 2002 ).

Critical habitat and recovery plans are central aspects of the ESA, but the law includes other significant regulations and conservation incentives. The most important of these is the protection of individuals from harm and species from extinction. Individual animals are protected from unregulated take (i.e., killing, harming, or harassing) by federal, state, and private parties (ESA sec. 9[a][1]). Habitat loss can be regulated as take, but only if it is likely to harm individual animals ( Babbitt v. Sweet Home Chapter of Communities for a Great Oregon, 515 U.S. 687, 707–709 [1995]). The destruction of unoccupied habitat does not constitute take, even if the area is important for recovery, because the absence of individuals precludes their being harmed ( New Mexico Cattle Growers Association v. United States Fish and Wildlife Service, 248 F.3d 1277 [2001]).

Plants are also protected from harm, but to a lesser degree than animals, especially on nonfederal land (ESA sec. 9[a][2]). State and private parties are permitted to take animals as long as “the taking will not appreciably reduce the likelihood of the survival and recovery of the species in the wild” (sec. 10[a][2][B][iv]).

Take by federal agencies is permitted as long as it does not “jeopardize”the existence of a listed species (sec. 7[a][2]). “Jeopardize”was defined by the Reagan administration in 1986 to mean “reduce appreciably the likelihood of both the survival and recovery of a listed species,” such that “injury to recovery alone would not warrant the issuance of a ‘jeopardy’ biological opinion” (Endangered and Threatened Wildlife and Plants: Interagency Cooperation, 50 C.F.R. pt. 402 [1986]). As discussed above, these regulations allowed continued population declines, and reduction of recovery potential, as long as species' survival was not placed at risk.

Using logistic regression, we estimated the accumulative effects of ESA listing that flow from actions other than critical habitat and recovery plans. In logistic regressions for improving and declining trends, the partial regression coefficients for time listed were highly significant (table 1) . In the early period, the likelihood of species improving more than doubled with each decade that they were listed, while the likelihood of species declining more than halved. These results are consistent with Rachlinski's (1997) finding, based on the 1994 USFWS biennial report, that species that were listed longer were more likely to be improving and less likely to be declining.

Rates of improvement, as indicated by odds ratios per decade listed, were lower in the late period (table 1) . The proportion of species declining appeared to level off after 10 years in the late period ( figure 1 ; USFWS 2003 ). To test for a nonlinear effect, we included an orthogonal quadratic term for “time listed”in the regression model for declining trend in the late period. The quadratic term was significant and negative (table 1) , confirming that the proportion of species declining approached a plateau with increasing time listed. Perhaps rapid early progress in addressing threats to species was followed by slower progress due to more intractable threats. Unfortunately, no specific data are available with which to test this hypothesis.

Because of their differing levels of regulatory protection, we expected animals to have stronger recovery trends than plants. Animals appeared to be more likely than plants to be improving, but they were also more likely to be declining in the late period (figure 1) . This pattern was confounded with other variables, as animals were more likely than plants to be listed for longer periods of time and to have critical habitat and recovery plans.

Correcting for confounding variables through logistic regression, we found that plants were less likely to be declining than animals in both periods (table 1) . The differences were not highly significant, however. Thus, the expectation that differences in levels of legal protection would result in poorer recovery trends was not supported by the data. It is possible that the relative simplicity of managing imperiled plants compensated for the lower level of legal protection they receive.

Although we developed no predictions concerning differences in trends among animals, it was clear that they were far from homogeneous.A strikingly higher proportion of amphibians and mollusks were declining, and a lower proportion improving, than of other animals (figure 1) .

Endangered species were significantly less likely to be improving than threatened species in early reports. They were also more likely to be declining in both early and late reports, although these differences were not highly significant (table 1) . A higher proportion of endangered species than of threatened species had recovery plans (84 percent and 70 percent, respectively), but the proportion of endangered species with critical habitat (36 percent) was much the same as for threatened species (35 percent). In light of the evidence that critical habitat may assist recovery, making critical habitat a higher priority for endangered species could to some extent compensate for the poorer recovery record of endangered species relative to threatened species.

Levels of conservation expenditure are known to be correlated in a complex manner with population trends of listed species ( Restani and Marzluff 2001 , 2002 , Miller et al. 2002 ). However, expenditure was not examined as an independent variable in this study, mainly because expenditure is only a proxy measure for the conservation actions to which expenditure is directed (primarily those already included in our analysis: listing and regulation of take, critical habitat, and recovery plans). Tracking of expenditures is also incomplete, inconsistent, and not always uniquely assigned to individual species and conservation programs ( USFWS 2000 , Hoekstra et al. 2002 , IG/USDOI 2003 ). Data that comprehensively identify expenditures by all federal, state, and private parties, separated by species and by program, were not available.

Our findings suggest that the ESA is effective and can be improved by prompt listing, protection of critical habitat, and dedicated recovery plans. Although few threatened and endangered species have fully recovered, the short time most have been protected (15.5 years on average) renders this a weak test of the effectiveness of the Endangered Species Act. A better measure is the extent to which the provisions of the ESA are moving species toward recovery.

Our analysis of USFWS and NMFS biennial reports indicates that the longer a species is listed and subject to the regulation of take, the more likely it is to be improving and the less likely to be declining, irrespective of recovery plans and critical habitat. This suggests that imperiled species should be listed under the ESA as soon as possible. Unfortunately, the ESA listing program has been chronically underfunded, and undermined by opposition to the listing of economically controversial species ( Sidle 1998 , Greenwald et al. 2005 ). The annual listing rate has declined steadily since 1994 and is currently at the lowest level in the history of the ESA ( Norris 2004 , Greenwald et al. 2005 ). Listing delays are likely to contribute to low population sizes at time of listing, which in turn slow the rate of recovery and make it more expensive ( Wilcove et al. 1993 ).

Critical habitat was strongly negatively associated with declining trends in the early period and positively associated with improving trends in the late period, suggesting that it has been effective in assisting species recovery, despite administrative barriers. Nonetheless, critical habitat was rarely designated after 1986 and is still resisted by the Department of the Interior ( Suckling and Taylor 2005 ). Recent court orders have resulted in the designation of more than 350 new critical habitats ( Suckling and Taylor 2005 ). Our results suggest that if this progress continues, the proportion of species with recovering trends will increase significantly.

Dedicated recovery plans were strongly associated with greater survival and recovery of listed species in both periods. Although progress was made in the 1990s toward reducing the backlog of recovery plans, the rate of plan development slowed significantly after 2000 ( Suckling and Taylor 2005 ). Our results indicate that if all listed species were given recovery plans, the proportion recovering would be significantly higher. Our results also confirm other studies that suggest single-species recovery plans perform better than multispecies plans. Wildlife agencies should reconsider the growing emphasis on multispecies plans, or at least take care to ensure that multi-species plans include the same level of attention to the needs of single species as is found in dedicated plans.

Development and implementation of recovery plans, protection of critical habitat, listing, and regulation of take require substantial federal funding. The USFWS estimates that $153 million is needed to complete work on the existing backlog of listings and critical habitat designations ( Whitfield 2003 ). We recommend that this program be fully funded. We also endorse the recommendation of Miller and colleagues (2002) , that the recovery program budget be increased by $300 million.

Boersma PD Kareiva P Fagan WF Clark JA Hoekstra JM . 2001 . How good are endangered species recovery plans?. BioScience . 51 : 643 – 649 .

Clark JA Harvey E . 2002 . Assessing multi-species recovery plans under the Endangered Species Act. Ecological Applications . 12 : 655 – 662 .

Clark JA Hoekstra JM Boersma PD Kareiva P . 2002 . Improving US Endangered Species Act recovery plans: Key findings and recommendations of the SCB recovery plan project. Conservation Biology . 16 : 1510 – 1519 .

Doremus H Pagel JE . 2001 . Why listing may be forever: Perspectives on delisting under the Endangered Species Act. Conservation Biology . 15 : 1258 – 1268 .

Foin TC Riley SPD Pawley AL Ayers DR Carlsen TM Hodum PJ Switzer PV . 1998 . Improving recovery planning for threatened and endangered species. BioScience . 48 : 177 – 184 .

Gerber LR Hatch LR . 2002 . Are we recovering? An evaluation of recovery criteria under the US Endangered Species Act. Ecological Applications . 12 : 668 – 673 .

Greenwald DN Suckling KF Taylor M . 2005 . Factors affecting the rate and taxonomy of species listings under the US Endangered Species Act. In Gobel D, Scott MJ, Davis FW, eds. The Endangered Species Act at Thirty: Renewing the Conservation Commitment. Washington (DC): Island Press. Forthcoming.

Hoekstra JM Clark JA Fagan WF Boersma PD . 2002 . A comprehensive review of Endangered Species Act recovery plans. Ecological Applications . 12 : 630 – 640 .

[IG/USDOI] Inspector General, US Department of the Interior . 2003 . Final Audit Report on Reporting and Recovery Planning and Implementation for Endangered Species, US Fish and Wildlife Service. Washington (DC): USDOI, Office of the Inspector General. Report no. 2003-I-0045.

Google Scholar

Lawler JJ Campbell SP Guerry AD Kolozsvary MB O'Connor RJ Seward LCN . 2002 . The scope and treatment of threats in endangered species recovery plans. Ecological Applications . 12 : 663 – 667 .

Mann CC Plummer ML . 1995 . Noah's Choice: The Future of Endangered Species. New York: Alfred Knopf.

Miller JK Scott JM Miller CR Waits LP . 2002 . The Endangered Species Act: Dollars and sense?. BioScience . 52 : 163 – 168 .

[NMFS] National Marine Fisheries Service . 1994 . Endangered Species Act Biennial Report to Congress, January 1992–June 1994. Washington (DC): Department of Commerce. (28 February 2004; www.nmfs.noaa.gov/pr/readingrm/ESABiennial/bien94.pdf ).

[NMFS] National Marine Fisheries Service . 1996 . Biennial Report to Congress on the Recovery Program for Threatened and Endangered Species, October 1, 1994–September 30. 1996. Washington (DC): Department of Commerce. (28 February 2004; www.nmfs.noaa.gov/pr/readingrm/ESABiennial/bien96.pdf ).

[NMFS] National Marine Fisheries Service . 2002 . Biennial Report to Congress on the Recovery Program for Threatened and Endangered Species, October 1, 2000–September 30, 2002. Washington (DC): Department of Commerce. (28 February 2004; http://www.nmfs.noaa.gov/pr/readingrm/ESABiennial/2002bien.pdf ).

Norris G . 2004 . Only 30: Portrait of the Endangered Species Act as a young law. BioScience . 54 : 288 – 294 .

[NRC] National Research Council . 1995 . Science and the Endangered Species Act. Washington (DC): National Research Council.

Pombo RW . 2004 . The ESA at 30: Time for Congress to Update and Strengthen the Law. US House of Representatives Resources Committee. (22 February 2005; http://resourcescommittee.house.gov/issues/more/esa/whitepaper.htm ).

Rachlinski JJ . 1997 . Noah by the numbers: An empirical evaluation of the Endangered Species Act. Cornell Law Review . 82 : 356 – 89 .

Restani M Marzluff JM . 2001 . Avian conservation under the Endangered Species Act: Expenditures versus recovery priorities. Conservation Biology . 15 : 1292 – 1299 .

Restani M . 2002 . Funding extinction? Biological needs and political realities in the allocation of resources to endangered species recovery. BioScience . 52 : 169 – 177 .

Schemske DW Husband BC Ruckelshaus MH Goodwillie C Parker LM Bishop JG . 1994 . Evaluating approaches to the conservation of rare and endangered plants. Ecology . 75 : 584 – 606 .

Schultz CB Gerber LR . 2002 . Are recovery plans improving with practice?. Ecological Applications . 12 : 641 – 647 .

Schwartz MF . 1999 . Choosing an appropriate scale of reserves for conservation. Annual Review of Ecology and Systematics . 30 : 83 – 108 .

Sidle JG . 1998 . Arbitrary and capricious species conservation. Conservation Biology . 12 : 248 – 249 .

Stinchcombe J Moyle LC Hudgens BR Bloch PL Chinnadurai S Morris WF . 2002 . The influence of academic conservation biology literature on endangered species recovery planning. Conservation Ecology . 6 : 15

Suckling KF Taylor M . 2005 . Critical habitat and recovery. In Goble DD, Scott JM, Davis FW, eds. The Endangered Species Act at Thirty: Renewing the Conservation Commitment. Washington (DC): Island Press. Forthcoming.

Tear TH Scott JM Hayward PH Griffith B . 1993 . Trend and prospects for success of the Endangered Species Act: A look at recovery plans. Science . 262 : 976 – 977 .

Tear TH . 1995 . Recovery plans and the Endangered Species Act: Are criticisms supported by data?. Conservation Biology . 9 : 182 – 195 .

[USDOI] US Department of the Interior . 2003 . Critical Habitat—Questions and Answers, May 2003. (22 February 2005; http://endangered.fws.gov/criticalhabitat/CH_qanda.pdf ).

[USFWS] US Fish and Wildlife Service . 1990 . Report to Congress: Endangered and Threatened Species Recovery Program. Washington (DC): US Department of the Interior.

[USFWS] US Fish and Wildlife Service . 1992 . Report to Congress: Endangered and Threatened Species Recovery Program. Washington (DC): US Department of the Interior.

[USFWS] US Fish and Wildlife Service . 1994 . Report to Congress: Recovery Program, Endangered and Threatened Species. Washington (DC): US Department of the Interior.

[USFWS] US Fish and Wildlife Service . 1999 . Report to Congress on the Recovery Program for Threatened and Endangered Species. 1996. Washington (DC): USFWS, US Department of the Interior. (22 February 2005; http://endangered.fws.gov/recovery/report_to_congress.html ).

[USFWS] US Fish and Wildlife Service . 2000 . Federal and State Endangered and Threatened Species Expenditures: Fiscal Year 2000. Washington (DC): US Department of the Interior.

[USFWS] US Fish and Wildlife Service . 2003 . Recovery Report to Congress: Fiscal Years 1997–98 and 1999–2000. Washington (DC): US Department of the Interior. (4 March 2005; http://endangered.fws.gov/recovery/reports_to_congress/97-2000/report_text.pdf ).

[USFWS] US Fish and Wildlife Service . 2004a . Recovery Report to Congress: Fiscal Years 2001–2002. Washington (DC): US Department of the Interior.

[USFWS] US Fish and Wildlife Service . 2004b . Threatened and Endangered Species System (TESS): Listed Species and Populations with Recovery Plans. Washington (DC): US Department of the Interior. (22 February 2005; http://ecos.fws.gov/tess_public/TESSWebpageRecovery?sort=1 ).

Whitfield J . 2003 . US Endangered Species Act turns 30: Birthday comes at critical point for US conservation policy. BioEd Online: Biology News from Nature News Service (23 December). (22 February 2005; www.bioedonline.org/news/news.cfm?art=698 ).

Wilcove DS McMillan M Winston KC . 1993 . What exactly is an endangered species? An analysis of the US Endangered Species List: 1985–1990. Conservation Biology . 7 : 87 – 93 .

Wilcove DS Rothstein D Dubow J Phillips A Losos E . 1998 . Quantifying threats to imperiled species in the United States: Assessing the relative importance of habitat destruction, alien species, pollution, overexploitation and disease. BioScience . 48 : 607 – 615 .

Table 1. Influence of the Endangered Species Act (ESA) on the improving or declining population trends of species: estimated odds ratios (with 95 percent confidence limits) and significance tests for logistic regressions of improving and declining trends on independent variables in the early (1990–1994; N = 666) and late (1997–2002; N = 1013) periods of this study

Figure 1. proportions of species in major taxonomic groups that were declining, stable, or improving in the late period of this study (1997–2002)., figure 2. proportions of species that were declining or improving in the early (1990–1994) and late (1997–2002) periods of this study, in five-year intervals of time listed. time listed was calculated from the effective date of final or emergency rule to the date of mid-period for extant species listed under the endangered species act, the date of delisting rule for recovered species, or the estimated date of extinction., figure 3. proportions of species that were improving or declining in the early (1990–1994) and late (1997–2002) periods of this study, with and without designated critical habitat and with and without multispecies or dedicated recovery plans under the endangered species act. critical habitat or recovery plans were considered absent unless present for two or more years at the mid-period date., author notes.

Email alerts

Citing articles via.

• Recommend to your Library

Affiliations

• Online ISSN 1525-3244
• Copyright © 2024 American Institute of Biological Sciences
• About Oxford Academic
• Publish journals with us
• University press partners
• What we publish
• New features  
• Open access
• Institutional account management
• Rights and permissions
• Get help with access
• Accessibility
• Advertising
• Media enquiries
• Oxford University Press
• Oxford Languages
• University of Oxford

Oxford University Press is a department of the University of Oxford. It furthers the University's objective of excellence in research, scholarship, and education by publishing worldwide

• Copyright © 2024 Oxford University Press
• Cookie settings
• Cookie policy
• Privacy policy
• Legal notice

This Feature Is Available To Subscribers Only

Sign In or Create an Account

This PDF is available to Subscribers Only

For full access to this pdf, sign in to an existing account, or purchase an annual subscription.

Click through the PLOS taxonomy to find articles in your field.

For more information about PLOS Subject Areas, click here .

• Endangered species
• Conservation biology
• Get an email alert for Endangered species
• Get the RSS feed for Endangered species

Showing 1 - 13 of 216

View by: Cover Page List Articles

Sort by: Recent Popular

Quantifying global redundant fisheries trade to streamline seafood supply chains

Caitlin D. Kuempel, Emma Arnett, Carissa J. Klein

Automated echolocation classifiers vary in accuracy for northeastern U.S. bat species

Donald I. Solick, Bradley H. Hopp, John Chenger, Christian M. Newman

Status and trends in the international wildlife trade in Chameleons with a focus on Tanzania

Maxim Conrad Isaac, Neil D. Burgess,  [ ... ], Claire Ract

Climate change increases threat to plant diversity in tropical forests of Central America and southern Mexico

Miguel A. Ortega, Luis Cayuela,  [ ... ], Jesús Muñoz

Thamnaconus multilineatus (Tetraodontiformes: Monacanthidae)">Morphological and genetic analysis for the diversity conservation of rare species, Thamnaconus multilineatus (Tetraodontiformes: Monacanthidae)

Tae-Sik Yu, Kiyun Park, Kyeong-Ho Han, Ihn-Sil Kwak

Integrating fish swimming abilities into rapid road crossing barrier assessment: Case studies in the southeastern United States

Ridge Sliger, Jessica Graham,  [ ... ], Brandon K. Peoples

Ceratozamia ">Past, present and future in the geographical distribution of Mexican Tepezmaite cycads: Genus Ceratozamia

Jorge Antonio Gómez-Díaz, César Isidro Carvajal-Hernández, Wesley Dáttilo

A multi-taxon analysis of European Red Lists reveals major threats to biodiversity

Axel Hochkirch, Melanie Bilz,  [ ... ], Thomas Zuna-Kratky

Using a substitute species to inform translocation of an endangered territorial mammal

Marina Morandini, John L. Koprowski

Covariation of taxonomic and functional facets of β-diversity in Chilean freshwater fish assemblages: Implications for current and future processes of biotic homogenization

Sergio A. Castro, Pablo Rojas, Irma Vila, Fabian M. Jaksic

Ursus americanus Pallas 1780 (black bear) from Northeastern Mexico">Free amino acid and acylcarnitine values in Ursus americanus Pallas 1780 (black bear) from Northeastern Mexico

Andres Abellan-Borja, Iram P. Rodriguez-Sanchez,  [ ... ], Antonio Guzman-Velasco

Diurnal raptors at rescue centres in the Czech Republic: Reasons for admission, outcomes, and length of stay

Gabriela Kadlecova, Eva Voslarova, Vladimir Vecerek

Establishing the relationship between non-human primates and mangrove forests at the global, national, and local scales

Stuart E. Hamilton, Andrea Presotto, Arthur J. Lembo Jr.

Connect with Us

• PLOS ONE on Twitter
• PLOS on Facebook

Home — Essay Samples — Environment — Human Impact — Endangered Species

Essays on Endangered Species

Endangered species essay topics and outline examples, essay title 1: vanishing wonders: the plight of endangered species and conservation efforts.

Thesis Statement: This essay explores the critical issue of endangered species, delving into the causes of endangerment, the ecological significance of these species, and the conservation strategies aimed at preserving them for future generations.

• Introduction
• Understanding Endangered Species: Definitions and Criteria
• Causes of Endangerment: Habitat Loss, Climate Change, Poaching, and Pollution
• Ecological Significance: The Role of Endangered Species in Ecosystems
• Conservation Strategies: Protected Areas, Breeding Programs, and Legal Protections
• Success Stories: Examples of Species Recovery and Reintroduction
• Ongoing Challenges: Balancing Conservation with Human Needs
• Conclusion: The Urgent Need for Global Action in Protecting Endangered Species

Essay Title 2: Beyond the Numbers: The Ethical and Moral Imperatives of Endangered Species Preservation

Thesis Statement: This essay examines the ethical dimensions of endangered species preservation, addressing questions of human responsibility, intrinsic value, and the moral imperative to protect and restore these species.

• The Ethical Dilemma: Balancing Human Needs and Species Preservation
• Intrinsic Value: Recognizing the Inherent Worth of All Species
• Interconnectedness: Understanding the Ripple Effects of Species Loss
• Human Responsibility: The Moral Imperative to Protect Endangered Species
• Conservation Ethics: Ethical Frameworks and Philosophical Perspectives
• Legislation and International Agreements: Legal Approaches to Ethical Conservation
• Conclusion: Embracing Our Role as Stewards of Biodiversity

Essay Title 3: The Economic Value of Biodiversity: Endangered Species and Sustainable Development

Thesis Statement: This essay explores the economic aspects of endangered species conservation, highlighting the potential economic benefits of preserving biodiversity, sustainable ecotourism, and the long-term economic consequences of species loss.

• Economic Importance of Biodiversity: Ecosystem Services and Human Well-being
• Sustainable Ecotourism: How Endangered Species Can Drive Local Economies
• Case Studies: Success Stories of Economic Benefits from Species Conservation
• The Costs of Inaction: Economic Consequences of Species Extinction
• Corporate Responsibility: Businesses and Conservation Partnerships
• Balancing Economic Growth with Conservation: The Path to Sustainable Development
• Conclusion: The Interplay Between Biodiversity, Economics, and a Sustainable Future

Endangered Species Extinction Paper

Circle of life: why should we protect endangered species, made-to-order essay as fast as you need it.

Each essay is customized to cater to your unique preferences

+ experts online

Endangered Species: The African Elephant

Endangered species: the factors and the ways to prevent, loss of habitat as one of the main factors of the increase in endangered species, endangered animals: the causes and how to protect, let us write you an essay from scratch.

• 450+ experts on 30 subjects ready to help
• Custom essay delivered in as few as 3 hours

Endangered Species in Vietnam: South China Tiger and Asian Elephant

Funding and support for people responsible for protecting endangered species, endangered animals and the acts to protect them, keystone species and the importance of raising endangered species awareness, get a personalized essay in under 3 hours.

Expert-written essays crafted with your exact needs in mind

De-extinction Can Help to Protect Endangered Species

Protection of endangered species can help us to survive, the way zoos helps to protect endangered species, ways of protection endangered species, sharks demand protection just like endangered species, the reasons why the koala species is endangered, the issue of philippine eagle endangerment, the issue of conserving endangered animals in the jungles of southeast asia, primates research project: the bushmeat crisis, the negative impact of the food culture on the environment and jani actman article that fish on your dinner plate may be an endangered species, nesting and population ecology of western chimpanzee in bia conservation area, human impact on red panda populations , the impact of climate change on the antarctic region, the ethics of bengal tigers, poaching and the illegal trade, giant pandas ailuropoda.

Endangered species are living organisms that face a high risk of extinction in the near future. They are characterized by dwindling population numbers and a significant decline in their natural habitats. These species are vulnerable to various factors, including habitat destruction, pollution, climate change, overexploitation, and invasive species, which disrupt their ecological balance and threaten their survival.

The early stages of human civilization witnessed a relatively harmonious coexistence with the natural world. Indigenous cultures across the globe held deep reverence for the interconnectedness of all living beings, fostering a sense of stewardship and respect for the environment. Nevertheless, with the rise of industrialization and modernization, the exploitation of natural resources escalated at an unprecedented pace. The late 19th and early 20th centuries marked a turning point, as rapid urbanization, deforestation, pollution, and overhunting posed significant threats to numerous species. The dawn of globalization further accelerated these challenges, as international trade in exotic species intensified and habitats faced relentless encroachment. In response to this growing concern, conservation movements emerged worldwide. Influential figures such as John Muir, Rachel Carson, and Aldo Leopold championed the cause of environmental preservation, raising awareness about the fragility of ecosystems and the need for proactive measures. International conventions and treaties, such as the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES), were established to regulate and monitor the trade of endangered species across borders. As our understanding of ecological dynamics deepened, scientific advancements and conservation efforts gained momentum. Endangered species recovery programs, habitat restoration initiatives, and the establishment of protected areas have all played a vital role in safeguarding vulnerable populations. However, the struggle to protect endangered species continues in the face of ongoing challenges. Climate change, habitat destruction, poaching, and illegal wildlife trade persist as formidable threats. Efforts to conserve endangered species require a multi-faceted approach, encompassing scientific research, policy development, sustainable practices, and international collaboration.

Leonardo DiCaprio: An acclaimed actor and environmental activist, DiCaprio has been an outspoken advocate for wildlife conservation. Through the Leonardo DiCaprio Foundation, he has supported various initiatives aimed at protecting endangered species and their habitats. Sigourney Weaver: Besides her notable acting career, Sigourney Weaver has been a passionate environmental activist. She has advocated for the protection of endangered species, particularly in her role as an honorary co-chair of the Dian Fossey Gorilla Fund. Prince William: The Duke of Cambridge, Prince William, has shown a deep commitment to wildlife conservation. He has actively supported initiatives such as United for Wildlife, which aims to combat the illegal wildlife trade and protect endangered species. Edward Norton: Actor and environmental activist Edward Norton has been actively involved in various conservation efforts. He co-founded the Conservation International's Marine Program and has been vocal about the need to protect endangered species and their habitats.

Amur Leopard (Panthera pardus orientalis) Sumatran Orangutan (Pongo abelii) Javan Rhino (Rhinoceros sondaicus) Vaquita (Phocoena sinus) Cross River Gorilla (Gorilla gorilla diehli) Hawksbill Turtle (Eretmochelys imbricata) Yangtze River Dolphin (Lipotes vexillifer) Philippine Eagle (Pithecophaga jefferyi) Sumatran Tiger (Panthera tigris sumatrae) African Elephant (Loxodonta africana)

1. Habitat Loss and Fragmentation 2. Climate Change 3. Pollution 4. Overexploitation and Illegal Wildlife Trade 5. Invasive Species 6. Disease and Pathogens 7. Lack of Conservation Efforts and Awareness 8. Genetic Issues 9. Natural Factors

The majority of the public recognizes the significance of conserving endangered species. Many people believe that it is our moral obligation to protect and preserve the Earth's diverse wildlife. They understand that losing species not only disrupts ecosystems but also deprives future generations of the natural beauty and ecological services they provide. Some individuals view endangered species conservation through an economic lens. They understand that wildlife and ecosystems contribute to tourism, provide ecosystem services like clean water and air, and support local economies. These economic arguments often align with conservation efforts, highlighting the potential benefits of protecting endangered species. Additionally, public opinion on endangered species is often shaped by awareness campaigns, education initiatives, and media coverage. Increased access to information about the threats faced by endangered species and the consequences of their decline has resulted in a greater understanding and concern among the public. Many people support the implementation and enforcement of laws and regulations aimed at protecting endangered species. They believe that legal frameworks are essential for ensuring the survival of vulnerable species and holding individuals and industries accountable for actions that harm wildlife. Moreover, individuals increasingly feel a sense of personal responsibility in addressing the issue of endangered species. This includes making conscious choices about consumption, supporting sustainable practices, and engaging in activities that contribute to conservation efforts, such as volunteering or donating to wildlife organizations. Public opinion can vary when it comes to instances where the protection of endangered species conflicts with human interests, such as land use, agriculture, or development projects. These situations can lead to debates and differing perspectives on how to balance conservation needs with other societal needs.

"Silent Spring" by Rachel Carson: Published in 1962, this influential book is credited with launching the modern environmental movement. Carson's seminal work highlighted the devastating impacts of pesticides, including their effects on wildlife and the environment. It drew attention to the need for conservation and sparked widespread concern for endangered species. "Gorillas in the Mist" by Dian Fossey: Fossey's book, published in 1983, chronicled her experiences studying and protecting mountain gorillas in Rwanda. It shed light on the challenges faced by these endangered primates and brought their conservation needs to the forefront of public consciousness. "March of the Penguins" (2005): This acclaimed documentary film depicted the annual journey of emperor penguins in Antarctica. By showcasing the hardships and perils these penguins face, the film garnered widespread attention and empathy for these remarkable creatures, raising awareness about their vulnerability and the impacts of climate change. "The Cove" (2009): This documentary exposed the brutal practice of dolphin hunting in Taiji, Japan. It not only brought attention to the mistreatment of dolphins but also highlighted the interconnectedness of species and the urgent need for their protection. "Racing Extinction" (2015): This documentary film by the Oceanic Preservation Society addressed the issue of mass species extinction and the human-driven factors contributing to it. It aimed to inspire viewers to take action and make positive changes to protect endangered species and their habitats.

1. It is estimated that around 26,000 species are currently threatened with extinction, according to the International Union for Conservation of Nature (IUCN). 2. The illegal wildlife trade is the fourth largest illegal trade globally, following drugs, counterfeiting, and human trafficking. It is a significant contributor to species endangerment. 3. The World Wildlife Fund (WWF) reports that since 1970, global wildlife populations have declined by an average of 68%. 4. Habitat loss is the primary cause of species endangerment, with deforestation alone accounting for the loss of around 18.7 million acres of forest annually. 5. The poaching crisis has pushed some iconic species to the brink of extinction. For example, it is estimated that only about 3,900 tigers remain in the wild. 6. The Hawaiian Islands are considered the endangered species capital of the world, with more than 500 endangered or threatened species due to habitat loss and invasive species. 7. Coral reefs, one of the most diverse ecosystems on the planet, are under significant threat. It is estimated that 75% of the world's coral reefs are currently threatened, primarily due to climate change, pollution, and overfishing. 8. The illegal pet trade is a significant threat to many species. It is estimated that for every live animal captured for the pet trade, several die during capture or transport. 9. The IUCN Red List, a comprehensive inventory of the conservation status of species, currently includes more than 38,000 species, with approximately 28% of them classified as threatened with extinction.

The topic of endangered species holds immense importance for writing an essay due to several compelling reasons. Firstly, endangered species represent a vital component of the Earth's biodiversity, playing crucial roles in maintaining ecosystem balance and functioning. Exploring this topic allows us to understand the interconnectedness of species and their habitats, emphasizing the intricate web of life on our planet. Secondly, the issue of endangered species is a direct reflection of human impacts on the environment. It brings attention to the consequences of habitat destruction, climate change, pollution, and unsustainable practices. By studying this topic, we can delve into the root causes of species endangerment and contemplate the ethical and moral dimensions of our responsibility towards other living beings. Moreover, the plight of endangered species evokes strong emotional responses, prompting discussions on the intrinsic value of nature and our duty to conserve it for future generations. Writing about endangered species enables us to raise awareness, foster empathy, and advocate for sustainable practices and conservation initiatives.

1. Dudley, N., & Stolton, S. (Eds.). (2010). Arguments for protected areas: Multiple benefits for conservation and use. Earthscan. 2. Fearn, E., & Butler, C. D. (Eds.). (2019). Routledge handbook of eco-anxiety. Routledge. 3. Groombridge, B., & Jenkins, M. D. (2002). World atlas of biodiversity: Earth's living resources in the 21st century. University of California Press. 4. Hoekstra, J. M., Boucher, T. M., Ricketts, T. H., & Roberts, C. (2005). Confronting a biome crisis: Global disparities of habitat loss and protection. Ecology Letters, 8(1), 23-29. 5. Kiesecker, J. M., & Copeland, H. E. (Eds.). (2018). The biogeography of endangered species: Patterns and applications. Island Press. 6. Laurance, W. F., Sayer, J., & Cassman, K. G. (2014). Agricultural expansion and its impacts on tropical nature. Trends in Ecology & Evolution, 29(2), 107-116. 7. Meffe, G. K., & Carroll, C. R. (Eds.). (1997). Principles of conservation biology. Sinauer Associates. 8. Primack, R. B. (2014). Essentials of conservation biology. Sinauer Associates. 9. Soulé, M. E., & Terborgh, J. (Eds.). (1999). Continental conservation: Scientific foundations of regional reserve networks. Island Press. 10. Wilson, E. O. (2016). Half-earth: Our planet's fight for life. Liveright Publishing.

Relevant topics

• Fast Fashion
• Ocean Pollution
• Water Pollution
• Deforestation
• Nuclear Energy
• Plastic Bags
• Air Pollution
• Climate Change

By clicking “Check Writers’ Offers”, you agree to our terms of service and privacy policy . We’ll occasionally send you promo and account related email

No need to pay just yet!

We use cookies to personalyze your web-site experience. By continuing we’ll assume you board with our cookie policy .

• Instructions Followed To The Letter
• Deadlines Met At Every Stage
• Unique And Plagiarism Free

• Subscription Information
• Terms of Use
• Excellence in Ecology Books
• Marine Ecology Books
• Diseases of Marine Animals Books
• Author Guidelines
• Authorship Policy
• Conflict of Interest Policy
• Open Access
• Rights & Permissions
• Transformative Journals
• For Librarians
• Ecology Institute
• Otto Kinne Foundation
• Job Openings
• Contact the journal
• Mailing List
• Latest Volume
• About the Journal

ESR 44:291-325 (2021)   -  DOI: https://doi.org/10.3354/esr01115

Review marine mammal conservation: over the horizon, sarah e. nelms 1, *, joanna alfaro-shigueto 2,3 , john p. y. arnould 4 , isabel c. avila 5 , susan bengtson nash 6 , elizabeth campbell 1,2 , matt i. d. carter 7 , timothy collins 8 , rohan j. c. currey 9 , camila domit 10 , valentina franco-trecu 11 , mariana m. p. b. fuentes 12 , eric gilman 13 , robert g. harcourt 14 , ellen m. hines 15 , a. rus hoelzel 16 , sascha k. hooker 7 , david w. johnston 17 , nachiket kelkar 18 , jeremy j. kiszka 19 , kristin l. laidre 20 , jeffrey c. mangel 1,2 , helene marsh 21 , sara m. maxwell 22 , aubrie b. onoufriou 23,24 , daniel m. palacios 25,26 , graham j. pierce 1,27 , louisa s. ponnampalam 28 , lindsay j. porter 29 , debbie j. f. russell 7,30 , karen a. stockin 31 , dipani sutaria 22 , nina wambiji 32 , caroline r. weir 33 , ben wilson 34 , brendan j. godley 1.

ABSTRACT: Marine mammals can play important ecological roles in aquatic ecosystems, and their presence can be key to community structure and function. Consequently, marine mammals are often considered indicators of ecosystem health and flagship species. Yet, historical population declines caused by exploitation, and additional current threats, such as climate change, fisheries bycatch, pollution and maritime development, continue to impact many marine mammal species, and at least 25% are classified as threatened (Critically Endangered, Endangered or Vulnerable) on the IUCN Red List. Conversely, some species have experienced population increases/recoveries in recent decades, reflecting management interventions, and are heralded as conservation successes. To continue these successes and reverse the downward trajectories of at-risk species, it is necessary to evaluate the threats faced by marine mammals and the conservation mechanisms available to address them. Additionally, there is a need to identify evidence-based priorities of both research and conservation needs across a range of settings and taxa. To that effect we: (1) outline the key threats to marine mammals and their impacts, identify the associated knowledge gaps and recommend actions needed; (2) discuss the merits and downfalls of established and emerging conservation mechanisms; (3) outline the application of research and monitoring techniques; and (4) highlight particular taxa/populations that are in urgent need of focus.

KEY WORDS: Conservation · Marine mammals · Priority setting · Management · Research techniques · Threats