how do zoos help research

Research in the modern Zoo

Zoos have come a long way from their beginnings as menageries in the 19th century. Rather than showcasing exotic animals purely for profit and entertainment as early zoos did, modern accredited zoos are active participants in scientific research and wildlife conservation. Research and conservation go hand-in-hand: in order to protect wild animals and their habitats, we need to understand these animals and the threats they face. Our mission at Zoo Atlanta – to save wildlife and their habitats through conservation, research, education, and engaging experiences – drives our contributions to these efforts. Read on to find out how to connect your students to current research and inspire conservation action within your classrooms.  

There are two broad types of wildlife research: in-situ research and ex-situ research. In-situ research is conducted out in the wild. This type of research can directly study the threats facing wild animal populations. It allows scientists to monitor and evaluate animal behavior, population dynamics, and ecosystem processes. The benefit of this type of research is that you are studying wild animals in their wild habitats. 

Ex-situ research is that which takes place outside of an animal’s natural habitat, such as here at the Zoo. This type of research can focus on topics like veterinary medicine, animal training, and individual animal personalities and behavior. Ex-situ research allows researchers to study animals up close and evaluate individual animal behaviors, development, and physiology. Ex-situ research can help conservation efforts that help protect wild animals and their habitats by providing information that would be difficult to obtain in the wild. It also helps zoos learn how to take better care of their animals. 

Zoo Atlanta participates in both in-situ and ex-situ research projects. In-situ research efforts are conducted through field work by zoo teammates and by providing support for the research projects of trusted partners. One effort we have participated in is the discovery and  naming of new species of amphibians . Dr. Joe Mendelson, the Director of Research at Zoo Atlanta, is heavily involved in these efforts and argues that taxonomy is “central to our understanding of the planet and central to our efforts to conserve our increasingly threatened biodiversity.” The Zoo partners with the Central Florida Zoo’s Orianne Center for Indigo Conservation and Auburn University to track and monitor re-released  eastern indigo snakes , many of whom were reared at Zoo Atlanta, in the Conecuh National Forest. We also work closely with the  Dian Fossey Gorilla Fund International , an organization devoted to researching and protecting gorillas in Rwanda and the Democratic Republic of Congo. One of our flagship projects focuses on studying a deadly fungus that has caused  Panamanian golden frogs  to become extinct in the wild. We care for a small population of these frogs at the Zoo with the hope that they can one day be re-released into the wild.  

Zoo Atlanta also conducts many ex-situ research projects on Zoo grounds. As one of the only zoos in the United States to house giant pandas, we have been able to  study giant panda  maternal behavior and sensory perception. These studies can help zoos take better care of panda cubs and provide better enrichment for pandas, while also providing insights that may aid wild panda conservation. The Zoo is the headquarters for the  Great Ape Heart Project , which aims to understand heart disease in great apes such as gorillas, orangutans, bonobos, and chimpanzees. The project studies the causes, diagnosis, and treatment for heart disease in great apes. We also collaborate with researchers from Georgia Tech to study how  elephants can use their trunks  to delicately pick up objects and suck in large amounts of water.  Veterinary medicine ,  Komodo  dragon genome  sequencing, and  sidewinder snake  movement and biodesign are just a few of the other ex-situ research projects that Zoo Atlanta participates in. 

Both in-situ and ex-situ research efforts are vital to wildlife conservation. Zoos are particularly well-situated to conduct ex-situ research, which makes them valuable partners to conservation organizations seeking to learn more about how to protect wild animals. They also support in-situ research projects by contributing money, providing staff and expertise to assist with these efforts, and educating the public about the value of research. You and your students can learn more about Zoo Atlanta’s research efforts by visiting the  Research  section on our website or reading  Beyond the Zoo , which outlines more ways that Zoo Atlanta contributes to wildlife research and conservation efforts. Advanced students who are interested in pursuing biological research can peruse our list of  Zoo Atlanta scientific publications . If you want to visit the Zoo, meet some of the animals we care for and study, and talk to knowledgeable Zoo Atlanta staff members, check out our  Teacher Resources  to start planning your trip

Connect With Your Wild Side #onlyzooatl

April 15, 2009

How Do Zoos Help Endangered Animals?

There are more to zoos than putting animals on display

Dear EarthTalk: Do zoos have serious programs to save endangered species, besides putting a few captives on display for everyone to see? -- Kelly Traw, Seattle, WA

Most zoos are not only great places to get up close to wildlife, but many are also doing their part to bolster dwindling populations of animals still living free in the wild. To wit, dozens of zoos across North America participate in the Association of Zoos and Aquarium’s (AZA’s) Species Survival Plan (SSP) Program, which aims to manage the breeding of specific endangered species in order to help maintain healthy and self-sustaining populations that are both genetically diverse and demographically stable.

The end goal of many SSPs is the reintroduction of captive-raised endangered species into their native wild habitats. According to the AZA, SSPs and related programs have helped bring black-footed ferrets, California condors, red wolves and several other endangered species back from the brink of extinction over the last three decades. Zoos also use SSPs as research tools to better understand wildlife biology and population dynamics, and to raise awareness and funds to support field projects and habitat protection for specific species. AZA now administers some 113 different SSPs covering 181 individual species.

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To be selected as the focus of an SSP, a species must be endangered or threatened in the wild. Also, many SSP species are “flagship species,” meaning that they are well-known to people and engender strong feelings for their preservation and the protection of their habitat. The AZA approves new SSP programs if various internal advisory committees deem the species in question to be needy of the help and if sufficient numbers of researchers at various zoos or aquariums can dedicate time and resources to the cause.

AZA’s Maryland-based Conservation and Science Department administers the worldwide SSP program, generating master plans for specific species and coordinating research, transfer and reintroductions. Part of this process involves designing a “family tree” of particular managed populations in order to achieve maximum genetic diversity and demographic stability. AZA also makes breeding and other management recommendations with consideration given to the logistics and feasibility of transfers between institutions as well as maintenance of natural social groupings. In some cases, master plans may recommend not to breed specific animals, so as to avoid having captive populations outgrow available holding spaces.

While success stories abound, most wildlife biologists consider SSP programs to be works in progress. AZA zoos have been instrumental, for instance, in establishing a stable population of bongos, a threatened forest antelope native to Africa, through captive breeding programs under the SSP program. Many of these captive-bred bongos have subsequently been released into the wild and have helped bolster dwindling population numbers accordingly.

Of course, for every success story there are dozens of other examples where results have been less satisfying . SSP programs for lowland gorillas, Andean condors, giant pandas and snow leopards, among others, have not had such clear success, but remain part of the larger conservation picture for the species in question and the regions they inhabit.

CONTACTS : AZA’s Conservation & Science Program, www.aza.org/Conscience .

EarthTalk is produced by E/The Environmental Magazine. SEND YOUR ENVIRONMENTAL QUESTIONS TO: EarthTalk , P.O. Box 5098, Westport, CT 06881; [email protected] . Read past columns at: www.emagazine.com/earthtalk/archives.php . EarthTalk is now a book! Details and order information at: www.emagazine.com/earthtalkbook .

The Case for Zoos: A Scientist’s Perspective

Andrew Cunningham

Deputy Director of Science

Andrew Cunningham, Deputy Director of Science, considers why zoos are important... and whether we actually need them at all any more. 

How can zoos justify their ongoing existence in this modern age, when information and images of any species under the sun is just a click of the mouse away?

Certainly this is a question that even I still ask myself occasionally, two years away from my 30 year anniversary as a veterinarian and conservation scientist within the Zoological Society of London’s academic faculty, the Institute of Zoology.

Working for a research institution linked to one of the world’s most famous zoos means we’re able to see first-hand the impact zoos have on conservation, with global research projects benefitting from the input and support from zoos.  

Do all zoos deserve to keep operating?

Certainly standards of animal welfare, enrichment and conservation work in the zoos of many developed countries have come on leaps and bounds in recent decades, but there are still sadly zoos in some parts of the world where radical improvements in animal welfare and management are required.

All zoos should not be tarred with the one brush, however. 

The positive effects of zoos

Let’s also consider the many positive impacts that well-managed, scientific zoos can have.

For example, there are few more effective ways to demonstrate the amazing diversity of life on Earth to those who don’t have the privilege of seeing the huge range of wild animals in their natural habitats around the world.

Enabling visitors to see animals up close has a lasting effect on how they view the natural world.

The concepts of zoos as ‘arks’ can be overblown at times but, speaking as someone with a background in wildlife veterinary science, I can personally vouch for how important insights gained in zoos can be for the conservation of wildlife in the field, both in terms of understanding animal behaviour and for exploring best-practice in managing threatened species in their natural habitats. 

The project I was involved in to save vultures from extinction in Asia was just one field conservation project that very clearly benefited from insights gained in zoos – the design and management of breeding centres was informed by the zoological world, and knowledge gained from investigating and treating disease in zoo animals proved invaluable in the wild.

Other examples include the ongoing battle against the chytrid fungus that’s currently devastating amphibian populations worldwide.

Again, zoos like ZSL and our partners around the world have a definite role to play in terms of maintaining breeding populations in captivity for species facing imminent extinction in the wild and in bringing this important story to the public through our exhibits.

Public knowledge and pressure inform human behaviours and government policies which, in turn, impact the conservation of animals in the wild.  

Modern zoos maintain high animal welfare standards while also running conservation projects in the field. They do, however, need to keep pushing themselves to demonstrate and communicate the impacts their work is having on the ground, including the incorporation of public outreach both locally and at conservation field sites.

There is a need for greater collaboration between those at the coal face of zoological science and those managing animal collections, to ensure this connection between zoos, field conservation and public education is as tangible, genuine and widely-understood as possible.

But given the dramatic and accelerating collapse in biodiversity currently being witnessed all around the world, the case for responsibly-managed zoos remains strong.

We know we can, and we will, find the solutions to create a better future, because the possibilities to revive nature are endless if we stand together.

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• Published: 28 June 2018

Evaluating the Contribution of North American Zoos and Aquariums to Endangered Species Recovery

• Judy P. Che-Castaldo   ORCID: orcid.org/0000-0002-9118-9202 1 ,
• Shelly A. Grow 2 &
• Lisa J. Faust 1  

Scientific Reports volume  8 , Article number:  9789 ( 2018 ) Cite this article

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• Biodiversity
• Conservation biology

The challenge of recovering threatened species necessitates collaboration among diverse conservation partners. Zoos and aquariums have long partnered with other conservation organizations and government agencies to help recover species through a range of in situ and ex situ conservation projects. These efforts tend to be conducted by individual facilities and for individual species, and thus the scope and magnitude of these actions at the national level are not well understood. Here we evaluate the means and extent to which North American zoos and aquariums contribute to the recovery of species listed under the U.S. Endangered Species Act (ESA), by synthesizing data from federal recovery plans for listed species and from annual surveys conducted by the Association of Zoos and Aquariums. We found that in addition to managing ex situ assurance populations, zoos frequently conduct conservation research and field-based population monitoring and assessments. Cooperatively managed populations in zoos tend to focus on species that are not listed on the ESA or on foreign listings, and thus it may be beneficial for zoos to manage more native threatened species. Our results highlight the existing contributions, but also identify additional opportunities for the zoo community to help recover threatened species.

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Introduction.

Due to the magnitude and complexity of the global extinction crisis, successful species conservation will require the engagement of all potential partners: state and federal agencies, non-governmental organizations, local communities and resource users, industry stakeholders, and wildlife managers 1 . These diverse partners each bring unique perspectives, expertise, and resources, not all of which will be appropriate or necessary in every case. However, a clear understanding of the potential contributions of each partner will help to identify the most relevant entities to call upon in each case.

Zoos and aquariums (hereafter, “zoos”) are becoming more broadly recognized as important partners for conserving threatened species 2 , 3 . There is a long history of zoos engaging in species recovery, from the American bison and California condor to the black-footed ferret and Panamanian golden frog 4 . However, the role of zoos in species conservation has often focused on ex situ species management, in particular ex situ breeding 5 , 6 . For example, the Conservation Measures Partnership’s Actions Classification 7 identifies 30 distinct types of conservation actions, but specifies a role for zoos in only two of those ( ex situ conservation, outreach and communications). The conservation value of ex situ breeding has also been somewhat controversial, with views ranging from it being a last resort that diverts resources from in situ efforts 8 , to part of a continuum of management actions for threatened species 9 . Even when ex situ breeding is acknowledged as part of the conservation strategy, the ability of zoos to sustain demographically and genetically viable populations for the long-term has been questioned 10 , 11 . Undoubtedly these issues and concerns must continue to be explored, but zoos also contribute to other conservation efforts beyond ex situ breeding 12 , 13 , 14 .

Several publications have explored generally how zoos contribute to species conservation, discussing both in situ and ex situ actions. Ex situ actions can directly target the species ( e . g ., ex situ population management, rehabilitation, gene banking) 7 , or indirectly support conservation through public outreach, biological and veterinary research, and fundraising for other organizations and projects 3 , 14 , 15 . In situ actions can include engaging and educating communities in the species’ native range, protecting and restoring habitat, supplying animals and/or staff for reintroductions, and field-based monitoring 3 , 15 . Although there are many case studies of these individual actions, the extent to which zoos contribute to conservation through these actions is not well understood. One study has evaluated the impacts of a subset of in situ conservation projects branded by the World Association of Zoos and Aquariums 16 , and another summarized the number of breeding and reintroduction projects for threatened species conducted by four Canadian zoos 12 . Thus far, no study has quantified both the in situ and ex situ conservation actions conducted by zoos at a national scale.

In the U.S., all institutions accredited by the Association of Zoos and Aquariums (AZA) include species conservation as a key part of their missions, in accordance with accreditation standards. To fulfill this part of their missions, zoos carry out an array of in situ and ex situ initiatives 4 , and collaborate with other conservation organizations and government agencies. This includes the agencies [U.S. Fish and Wildlife Service (USFWS) and National Oceanic and Atmospheric Administration (NOAA) Fisheries] that implement the U.S. Endangered Species Act (ESA), which was enacted in 1973 to protect threatened species through both extinction prevention and recovery actions 17 . However, the extent and scope of these zoo conservation efforts have not been systematically evaluated beyond annual reports within the zoo community.

The goal of this study was to evaluate the contribution of zoos to the recovery of threatened species in the U.S. by quantifying and summarizing their conservation activities. Our analysis consisted of three parts: (1) Summarize the management actions for which zoos are the responsible parties, based on data from federal recovery plans for listed species; (2) Summarize the recent conservation activities reported by AZA-accredited facilities in responses to the association’s annual field conservation and research surveys; and (3) Quantify the number of listed species that currently have managed populations in AZA facilities in order to identify additional opportunities for species conservation. Using multiple datasets allowed us to compare the contributions as self-reported by AZA facilities against those as recognized by the agencies responsible for implementing the ESA. Due to the scope of our study, we did not aim to quantify the impacts of these conservation activities, although it would be a valuable assessment that could be implemented following the methods of Mace et al . 18 .

In this study we focused on the terrestrial (including invertebrate and amphibian) and avian species listed under the ESA as of February 2017. Therefore, the large number of zoo conservation projects on marine and aquatic species, and the small number on plant species, were outside the scope of this assessment. Zoo conservation projects involving species with other risk statuses ( e . g ., Candidate, Under Review, or Proposed status under the ESA; state-listed; those ranked as Threatened (VU, EN, CR) or Extinct in the Wild (EW) under the IUCN Red List but not listed under the ESA) were also not represented in this assessment. Additionally, we focused on listed species whose native range included the U.S. ( i . e ., U.S. or U.S./foreign listings under the ESA; “U.S. listings” hereafter) in the first two parts of our analysis, but explored the overlap between both U.S. and foreign listings with managed zoo programs in the last section.

Roles of Zoos and Aquariums in Recovery Plans

The ESA requires every listed species to have a recovery plan, which documents the management actions and the criteria that determine when the species can be delisted. We gathered recovery plan data from the USFWS Recovery Plan Ad Hoc Report database ( http://ecos.fws.gov/ecp0/ore-input/ad-hoc-recovery-actions-public-report-input ), by querying all recovery actions that list a zoo, aquarium, or AZA (“zoos”) as the responsible party. As of September 2016, the recovery plans for 73 listed species (15.1% of the 482 listings that have recovery plans) named zoos as responsible for at least one recovery action. Of these, we focused on the 54 terrestrial and avian animals (6 amphibians, 31 birds, 7 invertebrates, and 10 mammals) for this analysis. Forty-two of these species are currently listed as Endangered and eight as Threatened, one is not listed due to extinction but was a species of concern at the time of recovery planning ( Moho bishopi ), and three have been delisted since the plan was written due to recovery ( Urocyon littoralis subspecies littoralis , santacruzae , and santarosae ).

In total, there were 38 recovery plans (some plans included more than one species) that described 468 recovery actions for which zoos were the responsible party. These actions involved 39 individual zoos or aquariums, or else listed AZA as the responsible party (see Table  S1 for complete list of institutions). We determined 11 keywords to represent the major types of conservation activities attributed to zoos (Table  1 ), which were derived through an iterative process. We started with 52 keywords used by AZA to categorize zoo conservation and science projects (see next section), and condensed them into 9 categories ( e . g ., anti-poaching/patrolling, disaster/emergency response, human-wildlife conflict, and wildlife trade were grouped into “threat mitigation”). We assigned these broader keywords to each recovery action based on the action descriptions from the plans, and added two keywords (fundraising, management/planning) to describe recovery actions that did not fit into existing keywords. In some cases multiple keywords were assigned to an action, resulting in a total of 605 keywords assigned.

The majority of recovery actions related to managing and/or maintaining an assurance population (36.1% of keywords), research (27.4%), and population augmentation (23.5%; Fig.  1A ). Research included a broad range of topics relevant to species recovery, from investigating the impacts of contaminants, to modeling disease dynamics, to evaluating methods for habitat restoration. Besides population augmentation, other in situ recovery actions primarily consisted of population monitoring and assessments (12.4%), but there were also a small number of projects related to mitigating threats (1.7%) and to protecting and restoring habitat (0.9%). An unexpected type of zoo recovery action was management and planning (8.3%), which included projects that either involved or supported decision-making by the recovery team, such as coordinating program components, prioritizing tasks, or evaluating existing strategies. These tasks help to improve efficiency and flexibility and therefore can contribute greatly to the success of a conservation program. Other previously recognized contributions from zoos such as education and outreach 7 , 19 and husbandry knowledge and veterinary care 13 were also represented in recovery plans (7.5% and 7.1%, respectively). Finally, zoos contributed to conservation by providing project funds (4.5%), which were raised not only through visitor fees 8 but also by securing state, federal, and private grants. The keyword related to providing rescue, rehabilitation, or sanctuary facilities did not apply to any zoo-based recovery actions described in these plans. However, they may be more likely to be included in plans for ESA-listed marine species ( e . g ., sea turtles).

Conservation activities carried out by North American zoos and aquariums for species listed under the Endangered Species Act, sorted by type using 11 keywords. The number of instances of each keyword is shown at the base of the bars. ( A ) Distribution of the 468 recovery actions for which zoos and aquariums are the responsible party as described in recovery plans; a total of 606 keywords were assigned. ( B ) Distribution of the 644 field conservation and research project submissions by zoos to the 2013–2015 Annual Report on Conservation and Science (ARCS) survey; a total of 786 keywords were assigned.

Recovery actions were distributed unevenly across taxa (Fig.  2A ), with the majority of actions pertaining to birds (357 out of 468 actions). This was because the Revised Hawaiian Forest Birds Recovery Plan 20 included a very similar set of up to 19 recovery actions for each of 19 different bird species (for a total of 289 recovery actions) that involved either the San Diego Zoological Society or the Honolulu Zoo. To compare recovery action types among taxonomic groups, we further clustered the 11 project keywords into three broader categories: ex situ , in situ , and knowledge/capacity. Ex situ included the projects related to animal care and management at zoos (i.e., assurance population, husbandry/veterinary care, rescue/rehabilitation/sanctuary), whereas in situ included projects that took place at the species’ native range (i.e., population augmentation, monitoring/assessments, threat mitigation, and habitat creation/restoration/protection). The remaining project types all focused on increasing biological knowledge or the capacity for conservation (i.e. research, education/outreach, management/planning, fundraising). For birds, all three categories of projects were similarly common, with a slightly lower proportion of in situ projects (Fig.  2A ). In contrast, in situ projects were the most common category for invertebrates. Knowledge and capacity-building projects (primarily research) were the most common type of zoo recovery action for mammals and amphibians, accounting for 56% and 40% of their action keywords, respectively.

Conservation activities carried out by North American zoos and aquariums for species listed under the Endangered Species Act, by taxonomic group. Activities were aggregated into three categories based on the activity type keywords: conservation knowledge or capacity (research, education/outreach, management/planning, fundraising), ex situ (assurance population, husbandry/veterinary care, rescue/rehab/sanctuary), and in situ (population augmentation, monitoring/assessments, threat mitigation, and habitat creation/restoration/protection). The total instances of keywords for each taxonomic group are shown in parentheses. ( A ) Distribution of the 468 recovery actions for which zoos and aquariums are the responsible party from recovery plans; a total of 606 keywords were assigned. ( B ) Distribution of the 644 field conservation and research project submissions by zoos to the 2013–2015 Annual Report on Conservation and Science (ARCS) survey; a total of 786 keywords were assigned.

In addition to working with federal agencies in recovery programs, zoos also collaborate with other partners, including academic institutions, research institutions, or universities (collectively “academic institutions”) and other non-governmental organizations (NGOs). Thus we also examined the involvement of these two types of partners in the recovery actions that specified zoos as a responsible party. All four recovery actions related to habitat creation/restoration/protection listed either academic institutions (2 actions) or other NGOs (2 actions) as additional responsible parties, suggesting such field projects may require larger collaborations to implement. Academic institutions were involved in nearly half of the actions with research as a keyword (54 out of 128 actions), but did not collaborate with zoos as much on other types of recovery actions (<13% for all other types). Other NGOs partnered with zoos most frequently on actions related to assurance populations (26 out of 169 actions) and research (26 out of 128 actions), but proportionally they collaborated primarily on actions related to education and outreach (14 out of 35 actions) and threat mitigation (2 out of 8 actions).

Although recovery plans provide an official documentation of the extent to which zoos participate in recovery programs when the plans were created, they do not provide the full picture. Nearly one-third of all U.S. listed animals do not have a recovery plan (482 out of 710 listed animal species had plans as of September 2016), and finalized plans are rarely updated and therefore tend to exclude more recent or current projects. Additionally, a zoo’s involvement may not have been explicitly described as a recovery action, or only the primary holding facilities may have been identified when multiple institutions are involved.

Conservation Activities Reported by Zoos and Aquariums

We next summarized zoo conservation activities based on the AZA’s field conservation and research surveys from 2013–2015. These surveys are used to produce the association’s Annual Report on Conservation and Science (ARCS; http://www.aza.org/annual-report-on-conservation-and-science ). In the field conservation survey, AZA member institutions report only their conservation efforts that have direct impacts on animals and habitats in the wild. In the research survey, they report on any hypothesis-driven research conducted at these institutions or by their staff and the resulting publications. Response rates differed between surveys and years, with 86–92% of institutions responding for the field conservation survey and 52–64% responding for the research survey between 2013–2015. Although this dataset likely underrepresents the conservation and research projects in zoos for listed species, it still provides the most comprehensive current summary of these activities across AZA. Because of the specific focus of these surveys, the responses would also exclude education programs that do not directly target the local communities in the species’ native range. Therefore our analysis leaves out many of the conservation-oriented education projects carried out by zoos, which can also have significant impacts on achieving biodiversity conservation 21 .

We queried the database of field conservation and research survey responses for references to ESA-listed species in the project titles, descriptions, or the selected focal species. We tallied the number of conservation project submissions, representing unique combinations of institutions, projects, and species. That is, the same project may involve multiple institutions, and we count these as unique projects for each institution. This is because each institution may submit the project under a different name or description, thereby making it difficult to consistently delineate unique projects. Between 2013–2015, 142 AZA institutions reported a total of 644 active conservation projects involving 74 ESA-listed, U.S. terrestrial and avian species (23 mammals, 21 birds, 12 amphibians, 11 reptiles, and 7 invertebrates). Of these, 50 are currently listed as Endangered and 24 as Threatened. Although 54 of the 74 listings have finalized recovery plans, only 18 of those plans mentioned zoos as responsible parties for recovery actions.

Similar to the actions from recovery plans, we assigned each zoo project from the survey data to one or more of the 11 keywords representing different types of conservation activities (Table  1 ). Of the 786 keywords assigned, most were related to research (25.2%), monitoring/assessments (17.6%), population augmentation (16.0%), and managing assurance populations (12.7%; Fig.  1B ). Fundraising directed to recovery programs or conservation organizations (for purposes unspecified in the survey response) accounted for 11.3% of the keywords. Projects related to education and outreach (targeting local communities in the species’ native range) accounted for 5.2% of the keywords, and all other keywords were used fewer than 3% of the time. Compared to the conservation actions described in recovery plans, zoos reported a smaller proportion of activities related to assurance populations, but a larger proportion related to monitoring and assessments, and to habitat creation/restoration/protection. This suggests that zoos are contributing more to in situ conservation projects than is recognized in recovery plans. Zoos also reported more fundraising projects than represented in recovery plans, and additionally reported several projects related to providing rescue, rehabilitation, or sanctuary facilities. Both data sources agreed that research made up a large proportion of the conservation activities in zoos, and that there was great variation in the types of research conducted. Research projects reported by zoos ranged from understanding the genetic structure of Hawaiian petrel ( Pterodroma sandwichensis ) populations, to measuring stress levels of Guam kingfishers ( Todiramphus cinnamominus ) in human care, to developing gene banking methods for black-footed ferrets ( Mustela nigripes ).

Comparing among taxonomic groups, the majority of zoo conservation projects involved listed mammal species (318 of 644 projects), and only 25 projects involved invertebrates. Although the distribution of projects among taxa is similar to a previous assessment of in situ conservation efforts by zoos around the world 16 , none of the mammalian species in our dataset were primates due to our focus on U.S. species. Based on the keyword categories we assigned to each project, we found in situ projects were most common for listed amphibians and invertebrates (Fig.  2B ), and they primarily consisted of population augmentation projects. Knowledge and capacity projects were least common for amphibians and invertebrates, but they made up the largest proportion of projects for mammals, birds, and reptiles (consisting primarily of research projects). Ex situ projects made up less than 20% of all conservation projects reported by zoos for listed mammals, birds, and reptiles. Compared to the actions from recovery plans, a larger proportion of in situ projects were reported by zoos for all taxonomic groups, and a smaller proportion of ex situ projects were reported for all taxa except amphibians (Fig.  2 ).

We estimated the amount that AZA zoos spend on listed species by summing the project expenditures reported in the ARCS surveys. From 2013–2015, total spending on the reported field conservation and research projects specifically targeting the 74 ESA-listed species summed to $28.9 million, or on average $9.6 million per year. For context, the reported average spending per year on the same set of species in 2013–2015 was $146.4 million by all federal agencies, and $7.9 million by all state agencies 22 , 23 , 24 . Among the different types of conservation activities, the majority of funds were spent on assurance populations, followed by population monitoring and assessment and research (Fig.  3A ). Comparing across taxa, expenditures were greatest on conservation projects for bird and mammal species (Fig.  3B ).

Spending by North American zoos and aquariums on conservation projects for species listed under the Endangered Species Act, as reported in the 2013–2015 Annual Report on Conservation and Science (ARCS) survey. The proportional spending (out of the total $28.9 M spent across 3 years) is shown by ( A ) project keyword and ( B ) taxonomic group.

Listed Species with Managed Populations in Zoos and Aquariums

The recovery plans and AZA surveys provide an overview of the extent to which zoos currently contribute to recovering listed species. However, additional opportunities for conservation may exist, as a number of ESA-listed species have ex situ populations in zoos that are cooperatively managed. Since the 1980s, zoos have collaborated in managing the animals in their care through goal setting, cooperative breeding, and exchanging animals across institutions, with the aim of improving the health (e.g., demographic viability, genetic diversity) of those zoo animal populations 25 , 26 . In North America, cooperatively managed populations are those with a Species Survival Plan ® (SSP) program, which is implemented by AZA member institutions. SSPs may also coordinate the conservation, research, and educational initiatives among institutions to support in situ species recovery. These programs therefore represent opportunities for zoos to contribute further to conservation efforts, because they have an established management structure and working partnerships across institutions. Cooperative management also generates a great deal of species-specific knowledge on breeding, veterinary care, behavior, and demography, which can inform or facilitate conservation actions. For example, knowledge on how to breed animals successfully and to care for and rear offspring may be important for helping to improve reproduction of a threatened species. Further, the establishment of an SSP program demonstrates a long-term commitment to the species by multiple AZA institutions, which may be leveraged to promote engagement in and support for wild populations of the same species.

Overall, 143 of the 482 SSP programs (29.7%) were for ESA-listed species, representing 154 listings (which included separate listings for Distinct Population Segments or subspecies of the same species). The majority of these were for species listed as Endangered (83.4%) and as foreign (77.9%). Of the 387 listings for U.S. terrestrial and avian species, 36 (9.3%) currently have zoo populations managed by an SSP program. Interestingly, only 14 of the 54 species whose recovery plans specified roles for zoos had SSP populations, and 24 of the 74 species identified in the AZA surveys had SSP populations. Only 10 species overlapped across the three datasets, meaning they have recovery plans that specified a role for zoos, conservation projects reported by zoos in AZA surveys, and zoo populations managed by an SSP program. This finding suggests that an SSP program is not required for zoos to participate in recovery programs, and many zoos work with listed species outside of the SSP framework. On the other hand, there are additional SSP programs that could participate in that species’ recovery but currently do not.

Most of the SSP programs for listed species involved mammals, with existing programs for 21 of the 74 (28.4%) U.S. mammal listings (Fig.  4A ). All other listed taxa were much less represented, especially invertebrates, for which the American burying beetle was the only listing (out of 148) with an SSP program. The picture was similar when including both U.S. and foreign listings, with 84 additional SSP programs for foreign-listed mammals, and a smaller number of additional SSP programs for foreign-listed birds and reptiles (14 and 13, respectively; Fig.  4B ). In summary, the majority of SSP programs did not manage listed species, but those that did tended to focus on species that were more at risk (listed as Endangered rather than Threatened). There was also a taxonomic bias for SSP programs to focus on mammals and a geographic bias for non-U.S. species, many of which were native to African and Central American countries. Our results parallel findings from a previous study that zoo and aquarium collections favor larger vertebrate species 5 . However, the bias of SSP programs toward non-U.S. species contrasts with an earlier finding that zoos tended to focus on mammal and bird species that are native to economically developed countries 27 .

The proportion of terrestrial and avian animal species listed under the Endangered Species Act that have cooperatively managed populations in AZA-accredited zoos and aquariums, by taxonomic group and listing status (T = Threatened, E = Endangered). ( A ) The proportion of U.S. listings with managed programs for the listed species. ( B ) The proportion of U.S. and foreign listings with managed programs for the listed species. ( C ) The proportion of U.S. listings with managed programs for a congener of the listed species. ( D ) The proportion of U.S. and foreign listings with managed programs for a congener of the listed species.

Zoos have the potential to contribute even further to species recovery, as shown by the number of listed species that have a congener with a managed SSP population in zoos (Fig.  4C,D ). Management of a closely related species in the same genus produces valuable husbandry and biological information that may be useful for informing the conservation of the listed species. Institutions holding the congeners may also develop education programs or design exhibits to promote conservation actions for the closely related listed species. Additionally, since zoos already have the resources and facilities to house a closely related species, it may be possible for those institutions to house the more threatened species instead, if ex situ breeding or rehabilitation is deemed beneficial (of course, species-specific behaviors and requirements will determine the extent to which that would be feasible, while threats and recovery strategies will determine the appropriateness of an ex situ breeding program). Across all taxa, there were SSP programs for the congeners of 70 out of 387 (18.1%) U.S. listings, and 299 out of 969 (30.9%) U.S. and foreign listings of terrestrial and avian species. In particular, there were managed programs for the congeners of 36.5% and 41.4% of U.S. listings for mammals and reptiles, respectively (Fig.  4C ), and 51.5% and 53.2% of total (U.S. and foreign) listings for mammals and reptiles, respectively (Fig.  4D ). This represents a significant body of knowledge and resources that could greatly enhance species recovery efforts, but have yet to be broadly utilized.

Our evaluation showed that zoos contribute to a diverse array of in situ and ex situ conservation efforts, and serve as important partners in the recovery of threatened species in the U.S. Zoo conservation activities (Table  1 ) spanned many of the conservation actions previously described 7 . Beyond maintaining ex situ populations 5 and increasing public understanding of biodiversity 21 , zoos carry out many more in situ projects than typically recognized (though see Olive and Jansen 12 ), including a large number of monitoring projects. We also found that zoos conduct a range of field- and zoo-based conservation research projects, which were nearly as numerous as ex situ breeding efforts (Fig.  1 ). Biodiversity monitoring and research both help to support successful species recovery, but they are not commonly viewed as significant ways in which zoos contribute to conservation. Our findings support earlier studies that showed these critical conservation actions are increasingly being funded or conducted by NGOs 28 , 29 , including zoos.

However, additional opportunities exist. We found that similar to zoo holdings overall 27 , managed SSP populations currently focus on non-threatened species. Among listed species, however, managed programs do tend to prioritize species that are more at risk of extinction. There are many considerations that determine the selection of species for zoo exhibits, and management programs are increasingly including conservation status in their decision-making. However, if a species is especially difficult to house, cannot reproduce successfully, or has low survivorship in zoos, then establishing ex situ populations may not be feasible or worthwhile. Further, there are ways to contribute to conservation even if zoos are managing the less at-risk species that are closely related to a threatened species, as discussed above.

U.S. zoos may also increase their conservation efforts by managing more native threatened species, as our results showed a tendency for SSP programs to focus on foreign-listed species. Ex situ populations would ideally be established in the species’ native range 2 , but currently >90% of the U.S. listed avian and terrestrial species do not have an SSP population in North American zoos. Further research is needed to evaluate whether and the extent to which those listed species would benefit from ex situ population management. Zoos are also carrying out relatively few education and outreach programs that directly impact listed species in the wild (Fig.  1B ). By including more native threatened species, zoos could develop associated education and outreach programs to engage the community most likely to impact the species and promote direct conservation actions. Of course, zoo education programs that do not directly affect wild populations are still valuable 21 , and we reiterate that our review did not summarize the magnitude of those existing efforts.

Finally, our findings suggest a need for greater coordination across zoos and better engagement with other conservation science partners. For example, 40 institutions reported working on various field conservation and research projects for the polar bear in the AZA surveys, but it is unclear the extent to which these efforts were coordinated to maximize their effectiveness. Only 5 recovery plans (for 5 species) named two or more zoos as the responsible party for any recovery action, suggesting such coordination among zoos is infrequent or poorly represented in plans. Only a quarter of the recovery plan actions conducted by zoos involved either academic or NGO partners, although integrating efforts into larger collaborations could lead to better outcomes 29 . However, coordination with other conservation partners may be increasing, as more partnerships between zoos and academic institutions are being formed ( e . g ., Smithsonian-Mason School of Conservation, the Phoenix Zoo - Arizona State University conservation partnership, the Living Earth Collaborative). Other zoo partnerships supporting species recovery include concentrated breeding centers and consortiums such as the Conservation Centers for Species Survival (C2S2), and AZA’s SAFE: Saving Animals From Extinction, a conservation framework launched in 2015 that prioritizes collaboration 14 . There are also efforts to integrate ex situ and in situ species management through the IUCN Conservation Planning Specialist Group’s One Plan Approach 30 , 31 .

In this assessment we focused on terrestrial and avian species listed under the ESA. Thus, the role of zoos in helping to conserve marine animals, plants, and species with other risk statuses remain to be examined. Additionally, further research is needed to evaluate the impacts of the many zoo conservation projects 18 , which could inform and improve future efforts. In summary, our study highlights the wide-ranging conservation actions conducted by North American zoos, and identify opportunities for better integration with the broader conservation community. By evaluating the current role of zoos in species conservation, our study provides a better understanding of the expertise, resources, and opportunities that zoos can offer as one of the many necessary partners in recovering threatened species.

Data availability

The recovery plan data analyzed in the current study are included in the Supplementary Information (Table  S2 ). The AZA survey data, except financial information, are available on AZA’s website ( http://www.aza.org/field-conservation ; http://www.aza.org/research-and-science ). Additional data are available from the corresponding author on reasonable request.

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Acknowledgements

We thank all of the AZA-accredited zoos, aquariums, and certified facilities that submitted information about their field conservation and research to AZA’s annual surveys. We also thank AZA’s Field Conservation and Research and Technology Committees for helping to refine surveys, review data submissions, and work with AZA members on their submissions. We thank A. Ahmad and S.Y. Kim for assistance with data compilation.

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J.P.C., S.G. and L.J.F. co-developed the project. S.G. compiled and analyzed the AZA survey data, and J.P.C. compiled and analyzed the recovery plan and managed program data, and prepared the manuscript and figures. All authors reviewed the manuscript.

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Correspondence to Judy P. Che-Castaldo .

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Che-Castaldo, J.P., Grow, S.A. & Faust, L.J. Evaluating the Contribution of North American Zoos and Aquariums to Endangered Species Recovery. Sci Rep 8 , 9789 (2018). https://doi.org/10.1038/s41598-018-27806-2

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DOI : https://doi.org/10.1038/s41598-018-27806-2

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