Biology Reference
In-Depth Information
And if we lose polar bears, it will be because climate change made their required hunting
habitat—sea ice—too rare.
Many species are in fact, to one degree or another, habitat specialists. Think, for example,
about the several species of prairie dogs that once were among the most abundant and wide-
spread vertebrate species in the American West. Prairie dogs can only live in short grasslands,
so they are true habitat specialists, but their habitat was once so abundant that they occurred
at high densities over a vast range. For most species, the condition that enable them to survive
and reproduce at high enough rates to persist over time are quite specific. As habitats change,
for whatever reason, species may have difficulty adapting; some may go into steep decline,
while a few may thrive. Thus, we may be misled if we think of today's habitat specialists as
being different from species we call habitat generalists. All species have some specific hab-
itat requirements, and we need to be alert to changes that may substantially affect their fate.
Currently rare species such as the Kirtland's warbler may require special and urgent atten-
tion, but in the long run, all species are vulnerable.
