Captive breeding and the reintroduction of Mexican and red wolves

Abstract

Mexican and red wolves were both faced with extinction in the wild until captive populations were established more than two decades ago. These captive populations have been successfully managed genetically to minimize mean kinship and retain genetic variation. Descendants of these animals were subsequently used to start reintroduced populations, which now number about 40-50 Mexican wolves in Arizona and New Mexico and about 100 red wolves in North Carolina. The original captive Mexican wolf population was descended from three founders. Merging this lineage with two other captive lineages, each with two founders, has been successfully carried out in the captive population and is in progress in the reintroduced population. This effort has resulted in increased fitness of cross-lineage wolves, or genetic rescue, in both the captive and reintroduced populations. A number of coyote-red wolf hybrid litters were observed in the late 1990s in the reintroduced red wolf population. Intensive identification and management efforts appear to have resulted in the elimination of this threat. However, population reintroductions of both Mexican and red wolves appear to have reached numbers well below the generally recommended number for recovery and there is no current effort to re-establish other populations.