How Do Marmosets Work?

These social, tree-dwelling monkeys are some of the smallest in the world. Learn more about them in this episode of BrainStuff, based on this article: https://animals.howstuffworks.com/mammals/marmoset.htm

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Episode Transcript

Speaker 1 (00:01):
Welcome to brain Stuff, a production of iHeartRadio, Hey brain
Stuff Lauren Vogelbaum here Curious, Lively and social. Common Marmosets
are a group of monkeys found primarily in the forested
areas of central Brazil and neighboring areas of South America.
There are more than twenty subspecies of marmosets, including the

(00:24):
pygmy marmoset, which is the world's smallest monkey. It weighs
on average just over four ounces that's about one hundred
and twenty grams and measures just over five inches in
length or about twelve centimeters. Marmosets are members of one
of five families of primates called Plattarines or New World monkeys.

(00:45):
That's because at some point millions of years ago they
separated from the primates of Africa and wound up on
the other side of the Atlantic. The apes and so
called Old World monkeys are catarines. Marsets are almost exclusively
tree dwellers. Their nostrils are rounded and further apart than catarines,
and though they do use their tails for balance, their

(01:07):
tails are not prehensile, meaning they can't grasp things with them.
Those tails are banded and long, usually longer than their bodies.
Even non pygmy types are pretty small. The average male
marmoset weighs about nine ounces or two hundred and fifty grams,
and will be just over seven inches in length that's
about eighteen centimeters. Females are just a little smaller. Their

(01:31):
facial skin is pale, but it darkens in the sun.
They're covered with fur that's flecked with brown, gray, and yellow.
They have large white ear tufts and the white blaze
on their forehead. Their hands and feet look very similar
to squirrels. Their thumbs are not opposable, and they have
claw like nails on all but their big toe. They

(01:53):
use these claws to help them move through the trees quickly,
using all four legs like squirrels, but also to scrap
and scratch tree bark to get at the gums, app
and resin that can make up to seventy percent of
their diet. Marmosets also forage four insects and eat fruit, seeds, fungi, nectar,
and small animals from snails to lizards to nestlings. They're

(02:17):
active for eleven to twelve hours a day after feeding
for an hour or so after waking, marmosets typically alternate
between resting, feeding, and socializing with their family group. According
to researchers, fifty three percent of their time is spent stationary,
sprawled out like their on summer vacation, but it's not

(02:37):
all rolling around the treetops. Being on the small side
means marmosets are particularly vulnerable to predators, especially raptors and owls,
tree snakes, wildcats, and mustelids like weasels, badgers, and ferrets.
In the wild. The average life span of the Carmen
marmoset is twelve years. For the article, this episode is

(02:59):
based on to Works checked in with the Wisconsin National
Primate Research Center at the University of Wisconsin Madison. The
center is currently home to about two hundred and seventy
marmosets who are helping researchers learn more about everything from
parenting to Parkinson's disease. Specifically, Hastiff Works spoke by email

(03:19):
with doctor Marina Emborg, a medical doctor, a professor of
medical physics, and the director of the pre clinical Parkinson's
Research program at the center. She explained that marmosets make
excellent subjects in neurological research for several reasons. Quote, their
shorter life span sixteen years in captivity means they reach

(03:39):
adulthood more quickly, they have babies more quickly. Also, when
you're studying neurogenerative disease like me, you need an older subject.
A recis monkey, for example, isn't old until it's twenty
five years old, but a marmoset has a shorter life span,
so it essentially speeds up the pace of research. She

(04:01):
says that marmoset's social cohesion they live in extended family
groups of up to fifteen or so also helps ho
stuff Works also spoke about email with doctor Tony Ziegler,
distinguished scientist at the Center who focuses her study on
that social order. Ziegler discovered that when a female marmoset
gets pregnant, a male marmosets are primed to support their

(04:24):
mate in a unique way. She said, marmosets in the
wild and in captivity will ovulate within two weeks after
giving birth and conceive over eighty five percent of the time.
The mom is in a cycle of a five month gestation,
and there are just two weeks out of the year
that she's not pregnant and Marmosets are multiple ovulators. They

(04:46):
give birth to twins and triplets in captivity, not really
in the wild. The twins can weigh twenty percent of
the mother's body weight, so they are a huge energetic
load and the mother needs helpers. The males are actually
going through hormonal changes along with their mates. It's likely
they're getting chemical signal communication that the mate is pregnant,

(05:06):
and they'll gain weight as the mate does during the pregnancy,
and they start having hormonal changes things like the estrogen
prolactin glucocorticoid changes, which is like cortisol before the babies
are born. Ziegler says that experiments in which sixty percent
of marmoset fathers went searching for their offspring when hearing

(05:28):
their recorded cry led her to believe that those marmoset
fathers had been better primed for fatherhood with their mates
and had better social bonding. As Ziegler said, marmosets are
great to work with. Their whole social system is amazing.
They're very curious, they love people. They love to observe
people as much as people love to observe them. It

(05:50):
makes for a great species to work with. Although responsible
Animal research is an important part of medical research that
can save and improve many lives. Marmosets do not make
good pets. They thrive when they're housed with their family members.
Captive marmosets can get bored and require the right sort

(06:11):
of stimulation and activity, which is truly a full time
job for researchers who work with them to provide in
those rare circumstances where they are kept in captivity. Today's
episode is based on an article marmosets are tiny upper
canopy dwelling monkeys on how Stuffworks dot Com written by

(06:32):
Patti Rasnesen. Brain Stuff is production of by Heart Radio
in partnership with how stuffworks dot Com and is produced
by Tyler Klang. Four more podcasts from my heart Radio,
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