Zoos play an important role in the care, public engagement, and conservation of many species. But, to save some threatened species, traditional zoos aren’t ideal. Ungulates (hoofed mammals like deer) need lots of land to maintain large populations that have enough genetic diversity to ensure long-term survival. The authors of a new paper published in BioScience, including CPSG Senior Program Officer Phil Miller, propose a novel way to give these species the space they need to thrive.
The 158 urban zoos accredited by the Association of Zoos and Aquariums (AZA) in the United States contain a little less than 11,000 acres of land, with an average of about 70 acres per zoo. This just isn’t enough space to maintain a diverse, healthy population of ungulates. To address this, the study authors propose partnering with breeding centers and private ranches – facilities with substantial land holdings – to build sustainable populations of these animals.
Numbers of the four African antelope species living on land that is part of the Source Population Alliance (SPA) and at North American urban zoos. Source: David Wildt, Philip Miller, Klaus-Peter Koepfli, et al., 2019, Breeding Centers, Private Ranches, and Genomics for Creating Sustainable Wildlife Populations, BioScience, https://doi.org/10.1093/biosci/biz091.
This partnership, which goes by the name of the Source Population Alliance (SPA), demonstrates how linking public and private sector resources can help endangered species survive. Zoos, breeding centers and ranches that become Alliance members can build effective insurance populations of animals whose numbers have dwindled in the wild. Currently, SPA member facilities provide a total of almost 80,000 acres of land for endangered species management. Importantly, population modeling shows that herds managed in this innovative way can grow to a larger abundance, and consequently remain more genetically diverse, than populations with less space.
Estimated future population abundance (top panel) and proportional genetic diversity retained (bottom panel) for simulated urban zoo (red line) and Source Population Alliance (blue line) populations. The green line in the bottom panel marks the level of genetic diversity retention typically targeted in long-term ex situ programs for endangered species. Source: David Wildt, Philip Miller, Klaus-Peter Koepfli, et al., 2019, Breeding Centers, Private Ranches, and Genomics for Creating Sustainable Wildlife Populations, BioScience, https://doi.org/10.1093/biosci/biz091.
The Source Population Alliance approach also embraces the value of efforts to both protect species and their habitats in the wild (in situ) and to maintain insurance populations in captivity (ex situ). In fact, because animals living at spacious breeding centers and private ranches live in environments more like their natural habitats, and because these animals are managed less intensively than those in zoos, the study authors think of their scheme as a third way that blends aspects of both in situ and ex situ conservation. They call it “sorta situ.”
Other authors on the study are from the Center for Species Survival, Conservation Centers for Species Survival, The Wilds, White Oak Conservation, Austin Savanna, African Lion Safari, and Fossil Rim Wildlife Center.
Photo Credit: Haytem93 [CC BY-SA 4.0 (https://creativecommons.org/licenses/by-sa/4.0)]