californianus), Kihansi spray toad (Nectophrynoides aspergini), Mauritius kestrel (Falco punctatus), Black Robin (Petroica traversi), and black-footed ferret (Mustela nigripes), which would all be extinct without zoo intervention.
Nonetheless, it remains unclear how relevant captive breeding programs in zoos have been or could be to conservation translocations in general. A global but dated review by Beck et al. (1994) showed zoos contributed to 59% of 129 reintroduction projects involving captive bred individuals. More recently, a review based on the Global Re-introduction Perspectives (GRP) case study series (Soorae 2008, 2010, 2011, 2013, 2016) published by the IUCN Reintroduction Specialist Group indicated that zoos were involved in only 35% of conservation translocations and contributed captive-bred individuals for release into the wild in only 20% of cases (Gilbert et al. 2017). We wondered whether such trends are representative in general and indicative of North American activities. North America is one of the world regions with the highest conservation translocation activity globally (Seddon et al. 2014), and North American zoos accredited by the Association of Zoos and Aquaria (AZA) annually spend on average US$160 million on conservation initiatives (AZA 2018), almost half of the US$350 million raised annually for conservation by zoo and aquarium associations around the world (Conde et al. 2011; Barongi et al. 2015).
Although the GRP case studies are a valuable resource, they stem from invited submissions and are not intended as an unbiased or systematic data set of conservation translocations generally. For example, although at least 279 animals species have undergone conservation translocations in North America (Brichieri-Colombi & Moehrenschlager 2016), GRP case studies have been published for only 48 (17%) of these. To expand understanding of the role of captive breeding and specifically of zoos in conservation translocations, we therefore mined less-biased data gleaned from a comprehensive literature review of animal conservation translocations in North America, including Canada, the United States, Mexico, Central America, and the Caribbean (Brichieri-Colombi & Moehrenschlager 2016). We used these data to examine what proportion of North American animal conservation translocations involve captive-bred source populations, and of these, what percentage come from zoos. Moreover, we asked to what extent zoo professionals actively contribute to the science of conservation translocations by reporting their insights and experiences in peer-reviewed journals. As animal-care specialists, educators, communicators, wildlife advocates, and scientists, zoo professionals have a diversity of skills to help advance the effectiveness of conservation translocations (Barongi et al. 2015), but few zoos have traditionally seen systematic research and publication as a priority (Griffith et al. 1989; Carr & Cohen 2011).
Methods
We used the North American Conservation Translocation (NACT) data set compiled by Brichieri-Colombi and Moehrenschlager (2016). This data set comprises publications on North American conservation translocations involving terrestrial, marine and freshwater animals published between 1974 and December 2013. Publications were compiled using the ISI Web of Science and Academic Search Complete search engines, which primarily identified journal publications but also some grey literature, such as agency reports and newspaper and magazine articles. We searched all publications in the data set for the words “zoo∗,” “aquarium,” “safari,” and “society.” We selected these terms by running a word frequency query on the names of all AZA accredited institutions to ensure that our search captured the majority of zoos; 85% of AZA-accredited institutions include one or more of these terms in their name. We selected all articles that contained the terms in the author affiliation, abstract, main text, or acknowledgements sections and then recorded the species involved, type of conservation translocation, zoo name or names, type of zoo involvement (e.g., captive breeding, authorship, funding, veterinary care, etc.), source population (captive or wild), and release location. We included articles that mentioned zoo involvement but did not mention the name of the zoo, but we eliminated articles that only included a general statement about zoos (e.g., “Zoo and botanic garden managers are rethinking their organizational missions”). We used R statistical software (R Core Team 2016) to derive descriptive statistics and run Pearson’s correlations on trends over time. Although we recognize that year of publication is an imperfect indicator of the timing of conservation translocations, we do not believe the variable time lag between implementation and publication introduces systematic biases in our analyses.
Results
Our NACT data set included 1863 articles, of which 231 (12%) did not specify the source of released animals. Of the remainder, 47% (768 articles) reported animals from captive-bred populations, 50% (816) from wild populations, and 3% (48) from both sources. Among the 279 species represented in the NACT database, 58% (162) featured in conservation translocations that released captive-bred animals.
The proportion of species whose conservation translocations involved releases from captive-breeding programs has not changed significantly since the 1970s (r = −0.137, p = 0.374). In fact, the proportion of publications mentioning releases from captive-breeding, which includes multiple articles for some species, has declined
Volume 33, No. 1, 2019
