The pitfalls of extrapolation in conservation: movements and habitat use of a threatened toad are different in the boreal forest

Abstract

AbstractWidely distributed species often vary geographically in their ecology. Thus, results of studies done in one part of their range cannot necessarily be extrapolated readily to populations elsewhere. This problem is particularly important for threatened species whose ecology has been studied in a few disconnected locations. The Canadian toad Bufo (Anaxyrus) hemiophrys occupies a large geographic range in western North America, but most studies of its ecology have been done in the prairies, where the species is considered to be closely associated with aquatic habitats. However, B. hemiophrys also occurs in boreal forest, where it faces threats from logging activities, especially if it uses upland habitats far from ponds and lakes. We radio‐tracked 29 toads in the boreal forest of northern Alberta, Canada to determine their patterns of movement and habitat use. Most movements between fixes were <50 m, but toads sometimes made longer movements exceeding 100 m. Over time, however, these short‐term movements combined into large‐scale directional movements that were highly variable among toads in both tortuosity and timing, but which generally took toads into upland forested habitats. Putative hibernacula also were located in upland sites. However, despite this terrestriality, toads still were associated with wetlands, using them significantly more often than would be expected based on their proportionate areal contribution to the landscape. Nonetheless, use of upland sites and long‐distance terrestrial movements differentiate this population of B. hemiophrys from those studied in prairie environments. Conservation plans based on what we know about the species elsewhere therefore would be inappropriate in this region. Management often requires site‐specific information, which can be obtained only from natural‐history studies of the populations in question.