Anybody who has ever opened a guidebook to birds or plants is
familiar with the range maps showing where a particular species
lives. Precise ranges are well known for organisms that are
well-studied, such as birds and trees in North America and
Europe. . In the tropics and for harder to observe organisms, in
contrast, we don't always know exactly where the organisms live.
We understand what limits species ranges and what defines range
edges for only a small handful of organisms. We do know climate
can play a large role in determining range limits, but other
factors such as soils and competing organisms also play roles.
Due to the computer revolution in biology, it has now become
commonplace to build correlational models that link the range of
a species to commonly measured (and easily available) climate
variables like mean annual temperature. These models are used
extensively to provide predictions about where poorly known
species live. They are also increasingly being used to make
predictions about where spe