Bureaucratic Mischief: Recognizing Endangered Species and Subspecies

Abstract

of the Act by well-intentioned government officials. The listing of certain species as endangered has encouraged an increase in investigation of these taxa, notably in molecular genetics and field ecology (1). In some cases the molecular genetic results contradicted previous ideas about species integrity or taxonomic distinctions that were based on phenotypic (morphological) descriptions. Unfortunately these traditional taxonomic designations have been and continue to be the bases for management and eligibility for protection. This is a significant problem because the Endangered Species Act not only protects listed taxa from hunting, habitat exploitation, and other perils associated with human coexistence, but also provides significant financial resources for the effort to protect these species and to stabilize their populations. To illustrate the problem we summarize the interpretive difficulties posed by molecular results for four endangered groups. The Florida panther. This is a small population of mountain lion (also called cougar or puma) that descended from the Felis concolor coryi subspecies that ranged throughout the southern United States in the 19th century (2). The few remaining panthers (c50) living in southern Florida show significant physiological and reproductive impairments that are likely the consequence of inbreeding depression. A recent allozyme and mitochondrial DNA (mtDNA) analysis of the population revealed that two very distinct genetic stocks were living in Florida (2), one that resembled other North American pumas and another that was more closely related to a puma subspecies that had evolved in South America. Apparently seven animals from a captive stock (that later turned out to be a mixture of authentic F. concolor coryi and South American founders) were released into the Everglades between 1957 and 1967 and promptly forgotten. Today the founder ecosystem contains a mixture of two subspecies. The genetic advantages of introducing some additional genetic material into a population suffering from inbreeding would have been comforting except for one detail. Three opinions from the Solicitor's Office of the Department of the Interior (which is the counsel of the U.S. Fish and Wildlife Service) have ruled with the force of precedent that hybrids between endangered species, subspecies, or populations cannot be protected. Their opinions, referred to here as the Hybrid Policy, concluded that protection of hybrids would not serve to recover listed species and would likely jeopardize S.J. O'Brien is chief of the Laboratory of Viral Carcinogenesis, National Cancer