a little above that level. Of the 17 named species, 11 are listed as Endangered and 3 are listed as Critically Endangered; the remaining 4 species are so rare and poorly known that they can only be listed as Data Deficient (Fig. 2.4) (SN Stuart et al., 2004). We consider this region to be a hot spot of extinction, and yet it is still very incompletely known. Based on our studies of altitudinal transects elsewhere in Middle America, we expect that the situation we have described for eastern Mexico is typical of mountainous parts of the entire region.
The amphibians at greatest risk of extinction are likely to be those with relatively few populations in areas undergoing rapid habitat conversion because of human activities. Populations that are already reduced in size