This is the copy I turned in. I may go back and fix some typos & at least one sentence I meant to change but did not complete the change (so it is fragmented). I was jammed for time to complete this project so it isn't exactly the finished product I had hoped for. I never proofread and edited it for a final version - i turned in this rough draft as a final draft. Still, the professor called it a "perfect paper" shortly after I turned it in (before she actually graded it). This was done for an Anthropology 101 course.

1. Wischnewsky 1/13
Louis Wischnewsky
Professor Monreal
Anthropology 101
28 April 2011
Visiting the Red-Cheeked Gibbon
My recent visit to San Diego Zoo was the second visit to the animal menagerie I have
ever made. A previous visit was made as part of a “short” vacation stop that lasted nearly a full
day. To appreciate the wide array animals at San Diego, my wife and I discovered on that trip
that more than a full day is needed. Recalling a great selection of hominids at San Diego,
wanting to visit the zoo again, and an opportunity to get discount future access, I felt another
visit to San Diego Zoo was ripe for the taking.
Located in the beautiful southern California city of San Diego, the San Diego Zoo is
arguably one of the most popular, famous zoos in the United States. A non-profit organization
founded in 1916, it boasts a membership of over a half-million persons making it the largest
zoological membership in entire world. The zoo itself rests on over 100 acres virtually in the
middle of San Diego and is home to over 4000 rare and endangered animals representing over
800 different species and subspecies. Often humorous, always interesting, and sometimes
exciting, there is ample inter-species mingling that adds to an aura, throughout the zoo, of
animals withing their natural habitats as best as can be expected within the 100 acres (watch out
for the duckling babies that can get under foot in seconds!). For example, always inspirational
are the geese that will aide parental ducks with babysitting those happy, curious ducklings.
Almost a year ago, our lives starting to calm down after a hectic start to the year, my wife
and I felt the need for a short get-away from the grind. I had never been to San Diego, it was
nearby, and Rosalinda had come across a deal on the internet that seemed perfect for what we

2. Wischnewsky 2/13
hoped to accomplish. In association with San Diego Zoo, a hotel on Shelter Island had a special
that made such a trip all the more attractive. Directly across San Diego Bay from the North
Island Naval Air Station and our room overlooking a private marina, the constant views were
awesome. We headed inland on two different days, though, once strolling the diverse vendors of
Old Town and spending another day taking in as much of the zoo as we could. Unfortunately,
after several days of strolling only a few of the many sites of San Diego, our feet, legs, and backs
were unable to carry us through the entire zoo. Enjoying the elevated walks and winding trails of
the zoo, however, we vowed to go back at the first opportunity. It had been my first ever visit to
San Diego Zoo and the first Rosalinda had taken in quite some time.
The zoo had been much fun. We had arrived mi-morning and, because it was directly in
front of us, started down the trails to the monkeys and apes. Huge avian fans, we spent much of
the day exploring various species of birds and sat through a rather humorous show at the Hunte
Amphitheater. There more to watch the animals, we avoided rides except for the Skyfari ride
back to the front of the zoo (our feet were killing us!). Unfortunately, though we spent roughly
six hours at the zoo, we just did not have the energy to take in all the sites and, as mentioned,
vowed a return.
Learning that a trip to a zoo would be expected at some point during the semester, my
wife and I were excited to learn that the San Diego Zoo was an option for this Anthropology
course. Even more exciting was the prospect of getting admission for a heavily discounted price
– and that admission allowing us future visits, as well.
Though we visited forty percent of the zoo on our recent trip, frankly, I did not create a
list of all the primates and varieties of them at the zoo. The volume of species at the zoo alone
dictates that focusing on a single order of animals to the extent of creating a list of all its
members would be cumbersome and most likely call for more than a day or even two of visiting

3. Wischnewsky 3/13
the zoo. The San Diego Zoo website, however, suggests there are three families of primates
represented at the park that consist of thirty-seven genera and 196 species (however, more than
three were observed).
The families include the following
✔ Callitrichidae (marmosets and tamarins)
✔ Cebidae (New World monkeys)
✔ Cercopithecidae (Old World monkeys)
A sampling of the groups I did note include the following:
✗ Red-Cheeked Gibbon
✗ Kikuyu Colobus
✗ Golden bellied Mangabey
✗ Francois' Langur
✗ L'hoest's Guenon
Unfortunately, to have this all flow together, a huge empty space was needed here … maybe this
is a great place for a copy of my ticket!

4. Wischnewsky 4/13
The following is a more detailed account of each species:
Kikuyu Colobus:
✔ Common Name: Kikuyu Colobus, fingernails
a.k.a, black and white colobus
✔ Forearms to hindlimbs ratio: Arms
✔ Scientific Name: colobus guereza appeared 10% to 15% longer than rear
kikuyuensis legs.
✔ Order: Primates ✔ Hand Grip: Did not observe enough
hand use to establish hand grip style
✔ Superfamily: Cercopithecoidea
✔ Primary Locomotion: Not enough
✔ Family: Cercopithecidae movement observed
✔ Subamily: Colobinae ✔ Sexual Dimorphism in size: Some
✔ Genus: Colobus specimens were noticeably, but not
largely, different in size. Sexual
✔ Species: Guereza dimorphism is assumed with males
✔ Number in cage: 3 (observed) about 10% larger than females
✔ Tail type: They have an ornate tail but ✔ Distribution: Kenya, east of the Rift
none exhibited characteristics of being Valley
prehensile ✔ Habitat: Secondary forests near rivers
✔ Nails on all digits? Too far to observe; ✔ Diet: mostly leaves
research indicates negligible
A pair of Kikuyu colobos relaxing at San Diego Zoo.

5. Wischnewsky 5/13
Golden-bellied Mangabey:
✔ Common Name: Golden-bellied they had nails at all
Mangabey
✔ Forearms to hindlimbs ratio: Arms &
✔ Scientific Name: cercocebus legs appeared equal in length
chrysogaster
✔ Hand Grip: small hands seen mostly
✔ Order: Primates used snacking and grooming
✔ Superfamily: Cercopithecoidea ✔ Primary Locomotion: quadrupedal
movement by one specimen in the cage
✔ Family: Cercopithecidae
✔ Sexual Dimorphism: The males
✔ Subfamily: Cercopithecinae appeared roughly 25% larger than the
✔ Genus: Cercocebus females
✔ Species: C. Chrysogaster ✔ Distribution: Democratic Republic of
the Congo, south of the Congo River
✔ Number in cage: 3 (observed)
✔ Habitat: Rain forests
✔ Tail type: non-prehensile
✔ Diet: Fruit, leaves, buds, insects, eggs,
✔ Nails on all digits? Could not see
fingers well enough to identify whether nuts, bark, and birds
A Golden-bellied Mangabey ready for a nap at San Diego Zoo.

6. Wischnewsky 6/13
Francois' Langur:
✔ Common Name: Francois' Langur; ✔ Nails on all digits? Not observable
a.k.a – Francois' Leaf Monkey, Tonkin from point of view
Leaf Monkey, White Side-burned
✔ Forearms to hindlimbs ratio: it
Black Langur
appeared legs were 20% to 30% longer
✔ Scientific Name: Trachypithecus than arms
francoisi
✔ Handgrip: These were at rest so grip
✔ Order: Primates was not observable
✔ Superfamily: Cercopithecoidea ✔ Primary Locomotion: bipedal &
brachiation
✔ Family: Cercopithecidae
✔ Sexual Dimorphism: No
✔ Subfamily: Colobinae
✔ Distribution: Northern Vietnam,
✔ Genus: Trachypithecus
southeastern China
✔ Species: francoisi ✔ Habitat: moist, deciduous forests
✔ Number in cage: 2 (observed)
✔ Diet: Leaves
✔ Tail type: non-prehensile
A pair of Francois' Langurs lounging in the sun at San Diego Zoo.

7. Wischnewsky 7/13
L'hoest's Guenon:
✔ Common Name: L'hoest's Guenon, ✔ Nails on all digits? Not observable
a.k.a. mountain monkey
✔ Forearms to hindlimbs ratio: about
✔ Scientific Name: Cercopithecus lhoesti equal
✔ Order: Primate ✔ Handgrip: looked as if they had full
hand use
✔ Superfamily: Cercopithecoidea
✔ Primary Locomotion: quadrupedal and
✔ Family: Cercopithecidae
bipedal
✔ Subfamily: Cercopithecinae
✔ Sexual Dimorphism: Yes
✔ Genus: Cercopithecus ✔ Distribution: Eastern Democratic
✔ Species: lhoesti Republic of the Congo, Burundi,
Rwanda, and into western Uganda
✔ Number in Cage: 2 (observed)
✔ Habitat: forest from dense to sparse
✔ Tail Type: non-prehensile
✔ Diet: fruit, leaves, eggs, small animals
A pair of L'hoests' Guenons having a snack.

8. Wischnewsky 8/13
In a discreet corner of Monkey Trail, I cam across a little tan colored monkey-like
creature that seemed enthralled by those observing her. It turned out she was what is commonly
called a red-cheeked gibbon and her much darker colored male counterpart had just swung onto
the limb behind her, placing his hands on her shoulders and looking past her at we creatures
outside their cage. It was a very brief scene but was cute enough to elicit warm smiles from both
myself and my wife. I do need to make it clear that the male did not “mount” the female, he
simply made a sort of embrace from behind for just a moment before moving on to other things
of more interest to him. It was as if he was just checking to see what it was that had her curiosity
in a reassuring way. The cute embrace and quiet isolation of the location prompted me to give
these two a longer watch.
First let me provide a general description of the two red-cheeked gibbons I observed. The
males are dark in color, almost black throughout except for their white or light tan colored
cheeks. The cheeks can appear to have a reddish or pinkish hue, thus giving them their common
name. They are not very large, probably weighing twenty-five pounds or less. Their arms are
their longest limbs and those arms appear rather muscular. Using brachiation as their primary
mode of mobility, it is no surprise their arms appear so strong and looked to be nearly 50%
longer than their legs. They do have opposing thumbs, but their elongated hands do not look to
be aided by thumbs during movement by brachiation. It appeared these Gibbons had fingernails,
but whether those nails were extended further than the fingers or were not fully developed on
some fingers was not determinable from my view. Sexual dimorphism regarding size does not
appear to exist. The female appeared smaller than the male, but this was very difficult to tell.
However, sexual dimorphism that easily separates males from females is in this species and
easily observable in that the males are dark as described, with the white or reddish puffy cheeks
but the females are a tan color all over their bodies. Easily, breeding and diet could cause a

9. Wischnewsky 9/13
female to be larger than the males. Thus, the sexual dimorphism appears to exist only in color.
The taxonomic information about this specimen:
Red-Cheeked Gibbon:
✔ Common Name: Red-Cheeked Gibbon ✔ Forearms to hindlimbs ratio: Arms 1.5
x hindlimb length
✔ Scientific Name: nomascus gabriellae
✔ Hand Grip: Almost exclusively
✔ Order: Primates
forefingers, thumbs used during eating,
✔ Superfamily: Hominoidea food gathering, and grooming only
✔ Subfamily: N/A ✔ Primary Locomotion: Brachiation
✔ Family: Hylobatidae ✔ Sexual Dimorphism in size: Not
significant, though the sexes do have
✔ Genus: Nomascus different coloring
✔ Species: Gabriellae ✔ Distribution: South Vietnam, southern
✔ Number in cage: 2 (1 male, 1 female) Laos, western Cambodia.
✔ Tail type: NONE ✔ Habitat: Tall, evergreen forests
✔ Nails on all digits? Appeared so, detail ✔ Diet: mostly fruit & leaves
not possible from vantage point
The male Red-Cheeked Gibbon … and the female Red-Cheeked Gibbon

10. Wischnewsky 10/13
What I observed:
Over the first thirty minutes, the female mostly lunged on a limb at the front of the cage
lazily basking in the sun and watching those passing by. The male moved about some, tinkering
from time to time with leafy snacks. However, just a few minutes over the half hour mark, a very
curious event happened that changed the behavior of both gibbons for a good while. Because the
last fifteen minutes had much activity, I had to change my method of observation. As a result,
below is a chart of what was observed for the first thirty minutes. After that is a log of events
taking place. Both periods were noted in three minute intervals. Some behaviors may have been
missed in the last fifteen minutes of observation because, while there was no erratic or radically
wild behavior, some movement of the two gibbons was fairly rapid. However, I believe any such
behaviors that were missed were observed in subsequent three minute periods.
Number of Occurrences at Interval (First interval was 9:33 AM)
Behavior :33 :36 :39 :42 :45 :48 :51 :54 :57 :00
Sitting 1 1 0 2 1 2 2 2 2 2
Eating 0 0 0 0 1 0 1 0 1 0
Scratching 0 1 2 2 0 0 0 0 1 0
Auto-
0 0 2 1 0 0 1 0 0 0
grooming
Grooming/
0 0 0 0 0 0 0 1 0 0
groomed
Inspecting 0 1 0 0 0 0 0 1 0 2
Courtship/
0 1 2 0 0 0 0 0 0 0
Courted
Present 2 2 2 2 2 2 2 2 2 2
Lounging/
1 1 0 0 1 0 0 0 0 0
Lying back
Hanging 2 0 2 1 1 0 0 2 0 1

11. Wischnewsky 11/13
As mentioned earlier, it was after this first half hour that something happened that
changed the dynamics of the cage and the two gibbons considerably. At 10:02 AM, a guided
group of children passed through the little enclave. These kids were probably ages seven to eight
years old and they were a very loud and raucous group. Though I was able to continue making
notations in three minute intervals, the next set of observations begins at 10:02 AM because that
was when the children came around the corner and seemed to be the likely cause of the behaviors
observed over the next quarter of an hour.
➢ 10:02 AM – Very loud kids.
➢ 10:03 AM – F. moving – front of cage watching kids closely, scratching self; male
rapidly joins her – female begins to make soft “whoo” sound aiming the call toward the
crowds gathering – then her call becomes REALLY loud as if warning – then the male
does it! Both making sound & aiming the calls toward the crowd – female begins to give
a display w/noise, “whooo” call becomes more like howling sounds.
➢ 10:06 AM – M. continues to howl – both have moved around. F soft howl to LOUD
howls – both have moved about. M. continues to howl – F. join now & then & can be
much louder than the M. Both are hanging next to each other. During displays the stay
close to each other – F. tends to be the one putting on displays, though M. has joined for
very brief moments.
➢ 10:09 AM – F. scratches self, moves near ground, then higher up. M. still howling – M
definitely not as loud as F.
➢ 10:12 AM – F. very loud again w/mild display. M still howls, but still relatively soft.
Both continue moving about – sharing pose. M tends to go to F; F. seems upset, shows
teeth in display now. F. has joined M after acting as if threatened.
➢ 10:15 AM – M seems to be cajoling F – his howls are more frequent when more ppl are
present, but softer – hers become very loud, almost scared. At times M faces F as he
makes his calls. She's self cuddled. When she howls, she aims the howls @ viewers while
M. aims his howls away from crowds when louder or at her when he his howling more
softly.

12. Wischnewsky 12/13
It was hard to determine through this observation whether males or females play a
dominant role in red-cheeked gibbon social units. The female did the territorial inspection twice
with the male joining only after she initiated the behavior. Both sexes were about the same size
so sexual dimorphism was not really present to determine if males play a dominant role.
However, the males and females are easily distinguishable by the color of their coats. The female
seemed more concerned with potential threats to the territory. Once the female had a reason to
feel threatened, she put up a noticeable display that the male joined. However, the male was not
as enthusiastic about the display and made his own inspection of the cage/territory. Satisfied
there were no actual threats within their territory, the male became much calmer. A couple of
times he sat or stood very close behind the female, almost in a courtship manner, while lowering
his howls to much softer tones than the female was using. It took the male several minutes to
reassure the female, in this manner, that there were no real threats. Still, the female was not fully
satisfied. Staying close to the male, looking to make sure he was close behind her, she would
then howl in the loud, bitter way at the passersby that were more animate. Throughout the event
displays of warning, with arms waving somewhat pacing in manner that seemed a warning (via
brachiation), were present even with the male.
Aspects of evolution were observable, as well. The forearms, as mentioned, were longer
than the hindlimbs. Since the red-cheeked gibbon obviously moves primarily through
brachiation, the strong, long arms made mobility very easy for this pair. From what I observed,
there was no apparent need for the males and females to have different colored coats. Depending
on the normal habitat, maybe the female's coat could blend with tree trunks better. It did seem
that the male has to win approval of the female and, perhaps, that is part of why the male has a
more ornate appearance. The problem with this hypothesis, though, is that it was definitely the
male that determined whether or not a threat actually existed and the female appeared to need the

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male's reassurance that everything was fine. This indicates to me that the female depends on the
male heavily for security or protection.
It was good to do the observation exercise. When I was an adolescent raising mallard
ducks, I got to know the species very well simply by watching my ducks sometimes for hours at
a time. This exercise reminded me that's really the only way to fully appreciate different
animals. As people, we do try to humanize some of the behaviors we observe in animals. Or so
that is the theory. I tend to think that we do the opposite. What we call humanity could be called
animality. The behaviors that we thus see in ourselves could be sometimes called animification
instead of personification in animals. In any case, whether we consider other species God's
creations or as having evolved from the same source, to get the best appreciation of our earthly
neighbors certainly requires spending time observing them for more than a minute or two passing
by a cage.