Recent captive-breeding proposals and the return of the ark concept to global species conservation.

Captive breeding for reintroduction is a much discussed tool in the management of endangered species. Although a number of high-profile case studies illustrate the critical role captive breeding can play in preventing species extinction (e.g., Stanley Price 1989; Kleiman & Rylands 2002; Cade & Burnham 2003), the available historical evidence indicates most reintroduction attempts failed (Griffith et al. 1989; Wolf et al. 1996). Over the past decade, the number of reintroduction programs and the body of scientific literature documenting these efforts has increased dramatically (Seddon et al. 2007), but the role of captive breeding remains controversial (e.g., Jule et al. 2008) despite well-documented successes. In its simplest form, the role of captive breeding and reintroduction in conservation is analogous to Noah’s ark. Species threatened with extinction are maintained in captivity, as if aboard an ark escaping the flood, until those factors threatening their existence are removed and they can be returned to the wild. This analogy has been widely used in the popular and scientific literature (Durrell 1976; Soulé et al. 1986; Balmford et al. 1995). Here I focus on the extent to which the importance of captive breeding and reintroduction as a conservation strategy is reflected in planning and policy, particularly by the world’s zoos and aquaria. I tracked policy and opinion in the zoo and conservation biology literature and found a general decline in emphasis on captive breeding since the early 1990s until the recent recommendations for large-scale captive breeding pertaining to hundreds of species from certain taxonomic groups. It is worth considering whether these new proposals are open to the same criticisms as their predecessors and whether they