Although the consequences of the homogenization of Earth’s flora and fauna are not well understood, experts agree that biological invasions pose hazards to rare species. As a result, there is a need for a systematic approach to assess risks from invasive species. The Relative Risk Model can be adapted to assess combinations of rare species, invasive species, and regions. It also can be applied ...

The pronghorn antelope (Antilocapra americana) is the rarest and least-known hoofedmammal classified as a game species in the state of Washington. (Woodland caribou, Rangifer tarandus caribou, are rarer, but are classified as Endangered under both Federal and Washington’s state endangered species statute). Although often called simply “antelope”, pronghorns are not true antelope at all; most au...

T he Endangered Species Act of 1973 addresses the market failure associated with the unpriced social benefits of such species. Robert Barnwell Roosevelt might have been envisioning such an act in his 1865 book Superior Fishing, where he wrote: ‘‘By these means can the seductive little beauties, whether of the feathered, furred, or scaly tribe . . . be preserved through endless time in undiminis...

By identifying the traits that characterize species likely to become endangered or fade to extinction, it is possible to afford them and their habitats extra protection and carefully monitor their status. The tragic losses of so many of these "red flag" species should be avoided in the future, and can be, with remedial action. Ideally, species should be conserved when their populations are stil...

Conservation genetics of endangered species has primarily focused on using neutral markers to determine units of conservation and estimating evolutionary parameters. Because the endangered Sonoran topminnow can be bred in the laboratory and has a relatively short generation length, experiments to examine both detrimental and adaptive variations are also possible. Here, we discuss over two decad...