Limited contributions of released animals from zoos to North American conservation translocations/Results

by Typhenn A. Brichieri-Colombi, Natasha A. Lloyd, Jana M. McPherson, Axel Moehrenschlager

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 slightly over time (r = −0.353, p = 0.019) (Fig. 1d) despite the increasing annual number of articles (Fig. 1a). Zoos have contributed animals toward releases of only 14% (40) of all animal species featured in published conservation translocations, and 25% of translocated species sourced from captive-bred populations, and this proportion has not changed significantly over time (r = 0.229; p = 0.135). Of the articles that reported captive-bred source populations, 16% (126) mentioned animals bred by zoos (Fig. 1b), and the proportion of zoo-bred source populations increased over time (r = 0.325, p = 0.0313) (Fig. 1d). Captive breeding by zoos was more likely to contribute to North American releases for amphibians (42%), terrestrial invertebrates (29%), mammals (19%), and birds (17%) than reptiles (15%), fish (2%), or marine invertebrates (0). Of the 54 zoos involved, 50 were in North America and 4 in Europe. Of the North American Zoos, 42 were AZA accredited, representing only 18% of 230 AZA institutions.

Zoo involvement of some kind was reported in 13% (242) of all 1863 conservation-translocation relevant papers. Zoo staff coauthored 5% of all papers in the NACT data set and 39% (94) of articles with zoo involvement. The proportion of publications with zoo staff as coauthors increased over time (r = 0.480, p < 0. 01) (Figs. 1c & d) from 0% in 1974 to 42% in 2013.

Figure 1. The number of papers on North American conservation translocations published annually from 1974 to 2013: (a) papers that involved captive breeding relative to all conservation translocation relevant papers in the North American Conservation Translocation (NACT) database, (b) papers that mentioned captive breeding by zoos relative to papers involving any captive breeding, (c) papers authored by zoo employees relative to papers with no authors involved with zoos, and (d) trend in proportions of NACT captive breeding, captive breeding by zoos, and authorship of researchers associated with zoos.