Yellow-bellied Marmot Alarm
Dr. Daniel T. Blumstein
University of California Los Angeles
What are marmot alarm
- Yellow-bellied marmots
(Marmota flaviventris) are sciurid rodents who are related to ground squirrels
and prairie dogs. Like all other marmots, yellow-bellied marmots whistle or
chirp when alarmed by a variety of predators, hence a common name "whistle
pig". Sometimes, they make a "chucking" sound, perhaps the
impetus for another common name, "rock chuck". When marmots are
very scared, the pace of their chirps quickens producing a "trill".
Collectively, these vocalizations are referred to as "alarm calls"
and individuals who hear them respond by immediately looking around and returning
to their burrows if they are not already at one.
When do marmots call?
- Marmots typically alarm
call when they see natural predators, such as coyotes, foxes, badgers, and
sometimes when they see eagles and other large birds. Depending upon where
marmots live and how used they are to people, marmots may alarm call when
they see a person. In areas where people are common (e.g., parks, hiking trails,
popular mountain summits), marmots may not alarm call and in fact may pay
little attention to people (or they may view people as sources of food!).
Marmots seem not to loose their fear of dogs though, and even in places where
dogs are common, dogs tend to scare marmots into calling. Other more natural
stimuli such as deer have different effects depending upon the marmots' history
of association with them. At Capitol Reef National Park, marmots live cheek
to jowl with numerous deer and virtually ignore them. In Colorado, marmots
may call hundreds of times to a deer foraging quietly nearby.
Why do marmots call?
- 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
What do alarm calls mean?
- Some species of animals
produce different types of calls in different situations. Many ground squirrels
"whistle" when they see a hawk and "trill" or "chutter"
when they see a coyote. When there is a strong association between the type
of stimulus and the type of vocalization, such calls function as rudimentary
words: animals hearing them know what type of predator is around and respond
Do yellow-bellied marmots
have different words for predators?
- In a word, no. Yellow-bellied
marmot chirps are their most common vocalization (97% of all vocalizations
are chirps). Chirps are very short vocalizations (typically 50 milliseconds
long) whose pitch, duration, and overall shape varies a bit. Yet, there is
no consistent association between the type of the predator and the acoustic
structure of their chirps. Yellow-bellied marmots chirp faster and produce
more chirps when they see canids (i.e., dogs, coyotes, etc.) and when alarming
stimuli get closer. The most extreme form of this is seen when marmots begin
trilling: quickly paced chips sometimes given as they disappear into their
burrows when being chased by canids or badgers. However, because marmots may
give the same number of chirps to different alarming stimuli, yellow-bellied
marmot alarm calls can not be said to be like rudimentary words: their calls
do convey the degree of risk a caller is experiencing and marmots who hear
the calls respond accordingly.
Do marmots sound the
same all over?
- Yellow-bellied marmots
sound like yellow-bellied marmots pretty much wherever you go. Individual
marmots may sound slightly different, but there is no evidence of dialects
in their alarm calls. Once you learn the distinctive call of the yellow-bellied
marmot, you'll be able to identify them throughout their Western North American
to The Marmot Burrow