By calling, animals make
themselves more obvious to a potential predator: a good way to find marmots
is to scare them into calling and then locate the caller. In making themselves
more obvious, animals may make themselves more likely to get caught. Thus,
there is an evolutionary quandary: how can alarm calling evolve if it's risky
to the caller? In some species of ground squirrels, individuals alarm call
to warn their genetic relatives: old individuals (usually females) who have
many relatives around call more than younger individuals. Thus, by warning
their descendants, callers are helping to preserve their genes.
Alarm calling in yellow-bellied
marmots is somewhat different. Adult females with newly emergent pups call
much more than all other marmots. Other animals without newly emergent pups
don't call that much even if they have a lot of genetic relatives around.
Thus a considerable amount of alarm calling is a type of direct parental
care where mothers call to protect their offspring. When marmots do call,
they seem to minimize the risk of calling whenever possible. Most alarm
calls are given by marmots who have already run back to their burrow before
calling.