Download - Zoo Lab Report 4:4
Zoo LabThe Observations of Two Different Primates
Biological Anthropology 0103Gabby Bryant
University of Maryland, College Park
Abstract
For this Zoo Lab, we were asked to visit the Smithsonian Zoo in Washington, D.C.
and observe Golden Lion Tamarin and another primate of our choice for thirty minutes
each. This would be used to compare their social behavior and locomotion to hypotheses
that we should have come up with before our observations. As my second primate, I chose
the Black Howler Monkey, which is related to the Golden Lion Tamarin, as they are both
New World Monkeys. During the observation of both of these primates, the Tamarin
displayed the most locomotion and movement, while the Black Howler Monkeys displayed
the most social behavior between the female, male, and their newborn baby. Although they
are very similar genetically, both species acted very differently in their environments and
toward one another, as well as with the humans that were observing them behind glass.
Introduction
The primate world is vast and diverse ranging from tiny marmosets in the forests of
Brazil to the large and proud gorillas in Africa. Each and every primate is unique, and yet so
closely related to other primates. As a whole, primates display three basic traits that link
them together: arboreal adaptation, dietary plasticity, and parental investment; however,
their behavior and morphologies vary from species to species, from large and imposing to
small and fast. For this lab, along with the Golden Lion Tamarin that we were told to study,
I chose the Black Howler Monkey. From the little I knew about both species, I drew some
questions related to their individual social behavior and locomotion. For the Golden Lion
Tamarin, I questioned if they would groom each other, and also if they would ever leave
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their branch perches and walk on the ground of their enclosure. As for the Black Howler
Monkeys, I asked questions when I first saw them, would the male and the female be
affectionate to one another, and if they would use their prehensile tails to swing among the
braches in their enclosure.
The Linnaean Classification system is a system that breaks all living things down
into categories or into “various levels of hierarchical classification”(Larsen, Clark, Spencer):
Kingdom, Subkingdom, Phylum, Subphylum, Superclass, Class, Subclass, Order, Suborder,
Superfamily, Family, Genus, Species, and Subspecies. Using this classification system,
Golden Lion Tamarin and Black Howler Monkeys are actually quite closely related. Alouatta
caraya is the Black Howler Monkey and Leontopithecus rosalia is the Golden Lion Tamarin.
Figure 1 displays the Linnaean Classification of both species of primate. (Eskeleton)
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As shown in the figure above, both the Golden Lion Tamarin and the Black Howler
Monkey share the same Superfamily, however their ancestries split off at the Family level.
They are both part of the Suborder Anthropoidea and the Infraorder Platyrrhini, which
means that they are both New World Monkeys; they are predominantly found in North and
South America.
Both species of primate have very interesting morphological features that vary. The
Golden Lion Tamarin are typically quite small, between six and ten inches long, with a ten
to sixteen inch tail that is non-prehensile, meaning that they cannot use it for swinging or
as an important fifth limb. Their name comes from their color and hair pattern: golden-red
in color and in a mane around a hairless face like a lion (Denver Zoo). Their dental pattern
is 2.1.3.2, which is different than other New World Monkeys and they have a small round
cranium. They have claws instead of nails and their “thumbs are not fully opposable and
their hallux (big toe) is located back from the other digits (similar to a bird’s big toe) and
retained its flat nail” (Zoo Atlanta). This allows the Golden Lion Tamarin to easily jump
from branch to branch and climb tree limbs. They are mostly completely arboreal. Also, like
most other primates, their scapulas are long and narrow.
Black Howler Monkeys, on the other hand, “are the largest monkey in Latin
American rainforests; they grow to be about two to four feet tall and weigh from eight to
twenty-two pounds. They have big necks and lower jaws, where their super-sized vocal
cords are housed” (Honolulu Zoo). Along with their huge vocal cords, they also have a
larger hyoid and angled jaw that allows them to “howl” quite loudly. This howling is used to
defend the Howler Monkey’s territory. Black Howler Monkeys are also not always black;
only the male is black, while the female is a lighter brown color, however they both have
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hairless faces. According to some experts, females are believed to be a brown color as a
survival strategy because it allows them to blend in with colors in the forest (Honolulu
Zoo). Black Howler Monkeys also have a useful prehensile tail. They are also sexually
dimorphic by size and by the size of their canines and have shearing crests that are useful
for their mainly foliage-based diet (Eskeletons).
Both of these species are native to South American and Central American rainforests
and both are arboreal. Golden Lion Tamarin prefer to stay in swampy humid areas in the
sub-canopy of the rainforest where they are protected from flying predators and are closer
to their food sources (Zoo Atlanta). Black Howler Monkeys prefer the larger branches
higher up in the rainforest where they walk from tree to tree in search of fresh, new leaves,
which serves as food (Rainforest Alliance). Both species are also diurnal.
For my trip to the zoo, I have made two hypotheses for both species in relation to
their locomotion and social behavior:
-Golden Lion Tamarin Social Behavior: I hypothesize that two monkeys will groom
one another during my visit.
-Golden Lion Tamarin Locomotion: I hypothesize that the monkey I am observing
will not walk on the ground of its enclose at all.
-Black Howler Monkey Social Behavior (This hypothesize was formulized after I had
been introduced to the enclosure at the zoo): I hypothesize that the male and female
monkeys will be affectionate to one another.
-Black Howler Monkey Locomotion: I hypothesize that the monkey will swing from
one branch to another using its prehensile tail.
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Materials and Methods
I planned to go to the zoo on Monday, April 2nd sometime in the early afternoon.
After a long and arduous metro ride, I finally made it to the National Zoo. I had brought
with me my lab report documents, a couple pencils and pens, and a camera to record the
primates I would be observing. Since I had been to the zoo recently, I knew where to find
the Golden Lion Tamarin, but still was not sure about which other primate I would observe.
I decided to walk around to the outdoor Gorilla enclosure, which was empty, to my dismay.
I thought that observing the Golden Lion Tamarin would be appropriate at that time, while
I was still deciding on the other primate. I walked back to the Small Mammal House and
waited in line as thralls of children in strollers crowded the entry. I had forgotten it was
Spring Break for students in Montgomery County, if not others. As I entered the Small
Mammal House a few minutes later, I quickly saw the first Golden Lion Tamarin enclosure
directly in front of me, which housed two Golden Lion Tamarin and an Elephant Shrew. I
handed my phone to the friend I had come with and asked him to start the stopwatch and
tell me when each minute had passed by. During the thirty minutes at the Golden Lion
Tamarin enclosure, I wrote notes each minute, took a few picture, and was jostled around
by other interested zoo-goers.
After the allotted thirty minutes had expired, I thought it would be a good idea to
continue through the Small Mammal House and explore the other species on display. I
stopped briefly at the Black Howler Monkey enclosure and was pleasantly surprised at
seeing a tiny baby attached to the stomach of the female. I was still not sure about
observing them for thirty minutes because I though observing gorillas would be more
interesting, but after about five minutes of ooing-and-ahhing at this adorable baby and its
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family, I decided to stay and time myself. Like the previous enclose, I took notes every
minute and a few pictures. After finishing with the Black Howler Monkeys, I had had
enough with the thralls of tourists and decided to head back to the metro.
Results
I will preface my results with this picture of me, which was a very embarrassing
picture to take, as I was in line with about ten five-year-olds and their parents:
Golden Lion Tamarin
The Golden Lion Tamarin that I decided to observe was in an enclosure with
another Golden Lion Tamarin and an Elephant Shrew. I believe that the Tamarin that I was
observing was a male and so was the other Tamarin. I will refer to the Tamarin I was
observing as Alpha and the other one as Omega. As I began observing Alpha, he was sitting
like a dog on a branch, simply observing everything around him with quick, jerking head
movements, but he was not paying any attention to Omega. After two minutes, Alpha began
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running up the branch he had been sitting on as Omega seemed to be yelling at him with a
squeaky sound. Alpha was running and jumping around the entire enclosure until he saw
Omega run into their “private hole” in the wall, and proceeded to follow him. When Alpha
exited approximately a minute later, he was holding a grape with one hand while still
walking along on the branches. He then sat on a branch and ate the grape piece by piece
while still ignoring Omega for about three minutes. After seemingly finishing the grape, he
jumped (again with one hand still on part of the remaining grape) to another branch, at
which time the piece of grape fell on the ground. He then retreated back into his hole
behind Omega. A minute later, he came out and quickly ran down a few branches until he
reached the ground where his grape had fallen. He picked up the grape skin, ate it, then
climbed up the metal cage material at the back of the enclosure until he made it to another
branch. For the next six minutes, Alpha jumps around some branches and paused, and then
jumped around again and perched. He seems to have zero interaction with Omega, finding
sniffing branches and stretching more interesting. He then retreated into his hole for
another three minutes. While he is in his hole, an arm reached out from a door below the
hole and threw small live worms into the enclosure. Omega immediately came out and
started picking up the worms from a log on the ground, as did (so it seemed) the elephant
shrew. Alpha slowly came out of the hole and proceeded to urinate off of a branch, then
wandered along a few branches before making his way down to the worm-covered log. He
took a few worms, then retreated into the branches, then came back down and tried to take
a few more. Alpha and Omega had no interaction. Out of nowhere, Omega attacked the
Elephant Shrew, which had been very close to the log, and everyone jumped around the
enclosure for a few seconds. Alpha retreated into the hole. He peaked his head out a few
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time, came out quickly a few minutes later while chewing on something, and then retreated
again.
Black Howler Monkey
I decided to observe the female Black Howler Monkey who’s name, according to the
Smithsonian website, is Chula. The male in the enclosure’s name is Pele, and together they
have a baby who was born on March 22nd (sex unknown) (National Zoo). I first observed
the Chula sitting on a high, thick tree limb with the baby attached to her underside while
Pele tried to get her attention by nudging her and reaching for her. She kept turning her
back on him. Pele them seemed to start humping her from behind. After about a minute,
Chula started walking around the limbs while Pele continued to follow her and nudge her.
If he was behind her, he would try to reach his hand around toward the baby. She
continued walking around for a few minutes while Pele followed her. As they both walked,
Alpha and Omega eating from the tree trunk on the ground with the elephant shrew to the side Alpha perched on a branch
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they would use their tails sometimes to wrap around passing branches. Eventually, he
started walking away and she followed him and they both sat underneath a heat lamp.
After a minute, Pele retreated into his hole and Chula followed him. She came out again as
Pele followed her and they went back up to her original tree branch. For the next couple
minutes, Chula walked around slowly while Pele continued to follow her and reach around
her front toward the baby. She eventually jumped around Pele and perched on top of a high
limb. Pele sat on a lower branch as she watched him watch us (the humans). Pele then
reached out and balanced his arms on the glass of the enclosure as his legs were still on a
limb and balanced there for a few seconds watching everyone. Meanwhile, Chula wrapped
her tail around a smaller branch while she sat and started scratching it and then putting
her fingers, near her nose. She then did the same thing to her back and her toes, and then
her genital area. Pele came back up to her and Chula made a loud sound at him. She then lay
down as Pele tried to nuzzle her. Eventually she ended up sitting with her arms and legs
wrapped around the baby as Pele lay next to her and they both went to sleep. Every few
minutes she would open her eyes and look around, but neither of them moved for the
remainder of the time.
Discussion
I was surprised by both of the species that I observed. I had hypothesized that the
Golden Lion Tamarin would groom one another because I believe that they would be more
social than they seemed, and that they would not go on the ground at all, which they did.
As I was observing Alpha, I noticed that he moved around a lot less than Omega and that he
seemed intimidated by Omega especially when there was food to be had. For the most part,
Alpha and Omega completely ignored each other and never once touched each other.
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Perhaps because they were both males (I am assuming), they had no purpose to interact
with each other. As for locomotion, I believed that Alpha would stay up in the branches and
move around a lot, however, because there was food on the ground, Alpha left the branch
and went to find it. I also found it very interesting that neither Alpha nor Omega really
cared about the elephant shrew until it came near their food.
The Black Howler Monkeys were, by far, the most interesting primate to observe.
Their behavior was fascinating and so was their locomotion. The entire time I was
observing Chula and Pele, Chula was trying to ignore and walk away from Pele as he
continuously followed her around. What was interesting was the speed at which they
moved: each moved very slowly. He seemed to want to take care of the baby or take part in
keeping it safe. Not only did Pele seem to want to take care of the baby, he also seemed to
Chula with her tail wrapped around a branch, baby clinging onto her underside
Chula and Pele sitting together under the heat lamp with the baby clinging to Chula
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want attention from Chula, which she was completely unwilling to give. Chula was not
affectionate to Pele in the least, however Pele did seem to nuzzle her and appreciate her a
little. As I watched Chula and Pele’s interactions, it reminded me of two young people in a
social situation where the female does not want to talk to the male, but the male is trying
his hardest to get her attention and gain her affection. As for using their prehensile tails,
neither Pele nor Chula swung from their tails, probably because the braches/limbs in their
enclosure were much too thick for a tail to wrap around. Chula did, however, wrap her tail
around a small branch when she was scratching herself, showing that it was capable of that
function. Having the baby in this enclosure definitely increased the behavioral observations
that could be made. Chula never seemed to really pay any attention to the baby that was
attached to her underside the entire time-at one point it even looked as though the baby
was feeding-until right at the end of the thirty minutes when she wrapped her entire body
around the baby as if to protect it and keep it warm as they slept.
Overall Locomotion
Climbing
Overall Social Interaction
Touch Between Species
Interaction With Observers
0 1 2 3 4 5 6
Golden Lion TamarinBlack Howler Monkey
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Figure 2 Displays the time spent for each primate between social behavior and locomotion,
out of 6 points.
As shown in the figure above, the Golden Lion Tamarin and Black Howler Monkeys
had much different outcomes between the time they spent interacting with others and the
time they spent moving around. It is clear that the Golden Lion Tamarin spent the most
time moving around, while the Black Howler Monkeys spent the most time interacting with
not only each other, but with the observers of their enclosure, i.e. the humans.
Conclusion
Overall this lab with very interesting and enlightening. Not only were two primates
researched and compared, they were also observed in person to better understand their
social behavior and their locomotion. Had these two species been in their natural habitats
and not in small enclosures in a zoo, they may have acted differently, but their main
characteristics were displayed very well. The Golden Lion Tamarin moved around a lot and
very quickly while searching for food, and Black Howler Monkeys moved around more
slowly while sometimes using their prehensile tails for support. In the end, the baby Black
Howler Monkeys stole my attention and created a very interesting environment to observe.
Had it not been there, my understanding and observations of the Black Howler Monkeys
would have probably been different. In the end, the actions of both primates exemplified
many actions that humans do every single day, just showing how close we as humans are to
our distant relatives, these other primates.
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Bibliography
Larsen, Clark, Spencer. Our Origins: Discovering Physical Anthropology. Page 36. New
York: W. W. Norton &, 2011. Print.
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Honolulu Zoo. "Black Howler Monkey." Association of Zoos and Aquariums, 2008.
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Eskeletons. "Taxonomic Tree." The University of Texas at Austin. Web. 04 Apr.
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<http://nationalzoo.si.edu/Animals/SmallMammals/News/baby-howler.cfm>.
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