Title: Modern Primates and Primate Behavior
1Modern Primates and Primate Behavior
- A Survey of Living Primates
- Anthropoids
2Anthropoids (Monkeys, Apes, and Humans)
- The anthropoid (humanlike) primates include
monkeys, apes, and humans. - Although there is much variation among
anthropoids, there are certain features that,
when taken together, distinguish them as a group
from prosimians. - Generally larger body size
- Larger brain (in absolute terms and relative to
body weight) - Reduced reliance on the sense of smell, as
indicated by absence of rhinarium and other
structures. - Increased reliance on vision, with forward-facing
eyes placed at front of face. - Greater degree of color vision.
- Back if eye socket formed by a bony plate.
3- Blood supply to brain different from that of
prosimians. - Fusion of the 2 sides of the mandible at the
midline to form one bone (in prosimians and
tarsiers they are joined by fibrous tissue). - Less specialized dentition, as seen in absence of
the dental comb and some other features. - Difference with regard to female internal
reproductive anatomy. - Longer gestation and maturation periods.
- More mutual grooming.
4- Suborder Anthropoidea is further divided into two
infraorders - Platyrrhini (NWM) flat-nosed
- Platyrrhini means flat nose and the noses of
the Central and South American monkeys have
widely spaced nostrils separated by a broad
septum. - Catarrhini (OWM) monkeys, apes, and humans
downward-facing nose - If you compare this with a typical OW catarrhine
nose (nostrils close together and facing
downward) you will see that they are comma
shaped and close together.
5Whitehead et al. 2005
6Which one is Catarrhini (OWM) and Platyrrhini
(NWM)
7Dental Formula
- NW and OW primates have different dental
formulas, that is, the number of each type of
tooth in each quadrant of the mouth. - OW have 2 incisors, 1 canine, 2 premolers
(bicuspids), and 3 molars - It is written as 2.1.2.3 ? 2 32
- 2.1.2.3
- Some NW anthropoids have 4 extra premolars
- 2.1.3.3 ? 2 36
- 2.1.3.3
- Other NW anthropoids have 4 fewer molars
- 2.1.3.2 ? 2 32
- 2.1.3.2
8- Moreover, because NW monkeys are almost entirely
arboreal, they have evolved long limbs, an some
have clawlike nails. - Several species also have a prehensile tail
giving them 5 grasping limbs - NO OW monkey has this adaptation
- Finally, two groups of platyrrhines, the
marmosets and tamarins, normally give birth to
twins.
9Howler Monkey Note the prehensile tail
10- The OW primates are divided into two
superfamilies. - The monkeys of Europe (now limited to Gibraltar),
Africa, and Asia make up superfamily
Cercopithecoidea - All OWM
- Apes and humans are in the superfamily
Hominoidea, which are then divided into three
families. - Hylobatidae
- Pongiade
- Hominidae
11The Superfamily Hominoida
- Contains the larger, tailless primates.
- The hominoidsapes and humansare generally
larger that the monkeys and have larger brains,
both relatively and absolutely. - Their brains also have neocortexes, meaning that
the hominoids are more intelligent as I have
already defined. - Finally, a series of traits make the hominoids
good suspensor climbers and hangers. - The traits behind this ability are a flexable
shoulder joint, a shoulder blade that is farther
back than in monkeys, and a stronger color bone
(clavicle) for added support.
12Family Hylobatidae
- Includes the gibbons and siamangs of Southeast
Asia and Malaysia. - There are 14 gibbon species and the closely
related siamang are today found in the
southeastern tropical areas of Asia. - These animals are the smallest of the apes, with
long, slender body weighing 13 pounds in the
gibbon and 25 pounds in the siamang. - The most distinctive structural feature of
gibbons and siamamgs is related to an adaptation
to brachiation.
13- Sometimes referred to as the lesser apes they
are noted for their brachiating mode of
locomotion - They have extremely long arms, long permanently
curved fingers, short thumbs, and powerful
shoulder muscles. - This highly specialized locomotor adaptation may
be related to feeding behavior while hanging
beneath branches. - The diet of both species is composed mainly of
fruit. - However, both (especially the siamang) eat a
variety of leaves, insects and flowers. - They also have unusual social organization for
primates. - Male and female hylobatids form monogamous pair,
though not necessarily a permanent one.
14Grey Gibbon (Hylobates muelleri)
15Siamangs (Hylobates syndactylus)
16Pongidae, (great apes)
- There are 4 species within the family
- Orangutan
- Orangutans (Pan pygmaeus) are represented by two
subspecies found today only in heavily forested
areas on the Indonesian islands of Borneo and
Sumatra. - As a result of human predation, they are an
endangered species. - Orangutans are slow cautious climbers whose
locomotor behavior can best be described as
four-handed, referring to the tendency to use
all your limbs for grasping and support.
17- They are mostly arboreal, however, they do
sometimes travel quadrupeadally on the ground. - Pronounced sexual dimorphism (males 200 lbs
females 100 lbs). - In the wild they lead solitary lives, although
adult females are usually accompanied by one or
two dependent offspring. - They are primarily frugivorous, but bark, leaves,
insects, and meant (on rare occasions) may also
be eaten.
18Orangutan (Pongo pygmaeus)
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20Gorilla
- Gorillas (Gorilla gorilla) are the largest of all
living primates. - They are limited to forested areas of western and
eastern equatorial Africa. - Generally, there are three recognized subspecies
- Western lowland gorilla
- Eastern lowland gorilla
- Mountain gorilla
- However, molecular data suggests that only one of
these, the western lowland gorilla is perhaps
sufficiently genetically distinct to warrant a
separate species.
21- The western lowland gorilla is among the most
numerous with perhaps a population size of
110,000. - Systematic studies of the free-ranging WLG did
not begin until the mid-1980s thus knowledge
about social structure and behaviors is still in
its infancy. - In general, it appears that their social
structure is simi8alr to that of mountain
gorillas, but groups are smaller and somewhat
less cohesive. - The eastern lowland gorilla is found near the
boarder of the DRC and numbers about 12,000.
22- The mountain gorilla probably have never been
numerous and number about 600 - Live in groups consisting of 1 (or sometimes 2)
large silverback males, a variable number of
adult females, and their offspring. - Silverback refers to adult males with white hair
across the saddle of their back (12-13 years) - Typically, but not always, both males and females
leave their natal group as young adults. - Females join other groups while males may live
alone for a while, or they may join an all male
group before eventually forming their own group.
23- Gorillas exhibit marked sexual dimorphism with
males (400 lbs) weighing twice as much as females
(100-200 lbs). - As a result of their weight, gorillas (especially
males) are primarly terrestrial and adopt a
semiquadrupedal (knuckle-walking) posture on the
ground. - All gorillas are almist exclusively vegetarian.
- MT gorillas concentrate primarily on leaves,
pith, and stalks. - WLG eat the same foods but also eat considerably
more fruit. - Not the myth of the killer ape.
24Right Western Lowland Gorilla
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27Chimpanzee (Pan troglodytes)
- Chimps are probably the best known of the all the
NHP - Chimp are found in equatorial Africa from the
Atlantic Ocean in the west to Lake Tanganyika in
the east. - Chimps are in many ways structurally similar to
gorillas, with corresponding limb proportions and
upper-body shape. - This similarity is due to commonalities in
locomotion when on the ground (quadruped knuckle
walking). - However, ecological adaptation of chimps and
gorillas differ, with chimps spending more time
in the trees. - Moreover, while gorillas are typically placid and
quiet, chimps are highly excitable, active, and
noisy.
28- Chimps are smaller than orangutans and gorillas,
but they do exhibit sexual dimorphism, just not
as much as orangutans and gorillas. Males just
over 100 lbs and females around 80 lbs. - In addition to knuckle walking, chimps (in
particular young) may brachiate while in the
trees. - On the ground, they frequently walk bipedally for
short distances when carrying food or other
objects. - They eat a variety of food items, including
fruit, leaves, insects, nuts, birds eggs,
berries caterpillars, and small mammals.
29- They live in large fluid communities of as many
as 50 individuals or more. - At the core of a chimp community is a group of
bonded males. - While this relationship is not always peaceful or
stable, these males use each other to defend
their territory. - Adult females tend of forage alone or in the
company of their offspring. - Their social behavior is complex and individuals
form lifelong attachments with friends and
relatives. - The bond between mother and child is strong
lasting their whole lives - Chimps live to their mid-30s early 40s
30Chimpanzees (Pan troglodytes) organize themselves
into complex social structures, requiring
considerable intelligence.
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32Bonobos (Pan paniscus)
- Are found only in an area south of the Zaire
River in the DRC. - They are among the least studied of the great
apes. - There are no accurate counts but it is believed
that their numbers are around 10,000 to 20,000 - They are sometimes called pygmy chimpanzee
because of their strong resemblance but smaller
size. - However, this title is a misnomer because in fact
bonobos exhibit several anatomical and behavioral
differences from chimps.
33- Physically
- They have a more linear body build
- Longer legs relative to arms
- A relatively smaller head
- A darker face from birth
- Tuffs of hair on the side of the face.
- They are more arboreal than chimps and appear to
be less excitable and aggressive. - Physical violence both within and between groups
are uncommon. - These groups are centered around female bonding
not male like chimps. - Bonobo sexuality is different than in chimps.
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