Reintroduction Programs

Reintroduction programs, by which animals raised or rehabilitated in AZA-accredited zoos or aquariums are released into their natural habitats, are powerful tools used for stabilizing, re-establishing, or increasing in situ animal populations that have suffered significant declines. Reintroductions may include animals that have spent some of their early life-stages being cared for in a “head-start” program that gives them a greater chance of survival than those born in the wild, those brought in for rehabilitation from illness or injury, those moved from one area for release elsewhere, or those that are offspring of animals that have had several generations cared for by AZA-accredited institutions.

AZA, the U.S. Fish and Wildlife Service (USFWS), and the International Union for the Conservation of Nature's (IUCN)/Species Survival Commission (SSC) play key roles in advancing the science of reintroduction programs in which AZA Animal Programs or its accredited institutions participate. Numerous reference materials and tools have been developed to advance the science and success of reintroductions.

Examples of AZA Reintroduction Programs

Black-footed Ferrets: The last 18 black-footed ferrets were placed in the care of AZA-accredited institutions. Due to the efforts of the AZA Black-footed Ferret SSP Program and other conservation partners, these animals have successfully reproduced and over 4,500 animals have been reintroduced into in situ populations. Learn more about this species’ road to recovery.

California Condors: In 1982, only 22 California condors existed in the wild, however conservation breeding and management of these animals in AZA-accredited institutions increased this population to almost 200 birds within 20 years, and by 2014, their population totaled 425 animals, including 219 living in the wild. To learn more about the condor's ex situ rearing efforts visit the San Diego Zoo website. Visit the USFWS Endangered Species Program to view a video of this success story.

Freshwater Mussels: Freshwater mussels are an imperiled group of North American animals with nearly 42% of the species found in the Ohio River basin. In 2001, the Columbus Zoo and AquariumOhio State UniversityOhio Department of Natural Resources Division of WildlifeU.S. Fish and Wildlife Service, Columbus Recreation and Parks Department and the Wilds founded the Freshwater Mussel Conservation and Research Center.  This Center has developed innovative methods and research which has yielded the exceptional propagation, culture, translocation, and introduction of numerous state and federally listed freshwater mussel species back into Ohio streams and rivers.

Golden Lion Tamarin: In 2003, the golden lion tamarin was downlisted by the IUCN from Critically Endangered to Endangered as a result of nearly thirty years of conservation efforts involving the Golden Lion Tamarin Conservation Program (GLTCP) at the Smithsonian National Zoological Park and the Associação Mico-Leao-Dourado in Rio de Janeiro. Conservation efforts included the establishment of a new population through translocation of 47 individuals in six groups, each isolated and evidently otherwise doomed in tiny isolated forests elsewhere, to a new protected area, the União Biological Reserve. Currently, about one-third of the wild population are descendants of the reintroduction program which has contributed significantly not only to the numbers of living in the wild, but also to the protection of 3,100 ha of forests within their range.

Karner Blue Butterfly: While healthy populations of the federally endangered Karner blue butterfly remain in a handful of its historic range states, the Karner blue butterfly disappeared from Ohio in 1992. In 1998, the Toledo Zoo became the first institution to breed the Karner blue butterfly for reintroduction into the wild at restored sites and later offered assistance to the Detroit Zoo, so that butterflies could be released at a site in southeast Michigan. To learn more about these efforts visit the Toledo Zoo and Detroit Zoo. Visit the USFWS Endangered Species Program to view a video about the Karner blue butterfly.

Oregon Spotted Frog: In 2014, the Oregon spotted frog was listed as threatened under the Endangered Species Act, after having been lost from almost 80% of its historic range. The Vancouver Aquarium, working with the Oregon Spotted Frog Recovery Team in Canada on a headstart program, bred this species for the first time in 2010 and release tadpoles and metamorphs into native habitat. Other partners, led by the Washington Department of Fish and Wildlife, are engaged in its recovery in the United States, including the Oregon ZooNorthwest Trek Wildlife ParkPoint Defiance Zoo & Aquarium, and Woodland Park Zoo. Visit the USFWS Endangered Species Program to view a video about how Oregon spotted frogs were raised from eggs and released into their native habitat.

Palila Hawaiian Songbird: The palila is one of the endangered Hawaiian honeycreeper species and efforts to expand the palila population back to its historic range at Pu`u Mali have included experimental releases of captive-bred birds, as well translocation of wild birds by the US Geological Survey. To learn more about how the palila is being bred for release to the wild visit the San Diego Zoo. Visit the USFWS Endangered Species Program to view a video about this project.

Red Wolf: The red wolf is one of the world's most endangered wild canids. Once common throughout the southeastern United States, red wolf populations were decimated by the 1960s due to intensive predator control programs and loss of habitat. A remnant population of red wolves was found along the Gulf Coast of Texas and Louisiana and efforts were initiated to locate and capture as many wild red wolves as possible. Of the 17 remaining wolves captured by biologists, 14 became the founders of a successful captive breeding program. To learn more about the red wolf breeding and reintroduction program visit the Point Defiance Zoo and Aquarium website. Visit the USFWS Endangered Species Program to view a video about this recovery effort.

Wyoming Toad: The Wyoming toad suffered rapid and dramatic population declines until 1994 when the wild population was officially classified as extinct and only one ex situ population remained. The ex situ population was successfully managed to produce tadpoles and toadlets that continue to be reintroduced into the wild. Unfortunately, the wild populations are not yet self-sustaining and still rely on regular releases. Read more about the Wyoming toad SSP Program in the U.S. Endangered Species Bulletin. Visit the USFWS Endangered Species Program to view a video about the Wyoming Toad.  

More Reintroduction Projects

To learn about other reintroduction projects AZA-accredited zoos and aquariums are studying, developing, or conducting, explore the Conservation and Research Database. Log in to AZA’s website, and select the Conservation and Research link. For reintroduction-related research projects, select “Research” as the project category, “Species and/or Habitat Conservation” as the keyword category, and “Reintroduction and Translocation” as the keyword. For field projects, select “Field Conservation” as the project category, “Ex Situ-Related” as the keyword category, and “Reintroduction” as the keyword.

AZA Guidelines for Reintroduction of Animals

AZA asserts that the scientific and ethical complexity of reintroduction necessitates guidelines for those who plan, conduct, fund, regulate and publicize reintroductions and in 1992 developed a bibliography that identified a variety of documents addressing reintroduction guidelines.  These guidelines are often contradictory and AZA has suggested that sincere consideration be given to all bibliographic sources and guidelines during the planning stages of reintroduction, and that reintroduction be regarded as science, with surveys of the pertinent literature, interdisciplinary participation, formulation of testable hypotheses and goals, thorough documentation, rapid publication of results, and review of the program by independent referees be incorporated.  Read more about the AZA Guidelines for Reintroduction of Animals.

IUCN/SSC Re-Introduction Specialist Group

The Re-Introduction Specialist Group (RSG) promotes the reintroduction of viable populations of animals and plants back to their natural ecosystems, contributing to conservation efforts worldwide. The RSG manages a network of global voluntary members to provide reintroduction practitioners with tools such as reintroduction guidelines, networking resources, and publications to provide a means for distributing information on reintroduction projects. Practitioners are encouraged to explore the RSG’s website for the most  current resources about reintroduction and other conservation translocation efforts.

Avian Reintroduction and Translocation Database

In 2008, the Lincoln Park Zoo established an Avian Reintroduction and Translocation Database (ARTD) to centralize information about the species, release sites, and release events that take place around the world. The database describes every aspect of the reintroduction effort for each species including the variables that impact the efficacy of releases, species biology and ecology, habitat suitability, demography, and genetics.

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