Biomedical Engineering Reference
In-Depth Information
genetic differences, significant differences in response to
experimental treatment among longtail macaques from
different countries of origin have been reported (
Schmidt
et al., 1977; Migot-Nabias et al., 1999; Menninger et al.,
2002
).
Taiwanese Macaques
Taiwanese macaques, also known as Formosan rock
macaques or black-limbed monkeys, are believed to have
once preferred coastal areas of Taiwan but, largely due to
human activity, today predominantly inhabit the moun-
tainous regions of central and southern Taiwan. They can
live at sea level or at elevations as high as 3400 meters.
They probably once lived in much larger groups than today
and probably suffered a severe loss in population size in
recent times, as most groups now include a single adult
male. However, recent conservation efforts following the
enactment of the Wildlife Conservation Act have signifi-
cantly increased their population size which,
Pigtail Macaques
Pigtail macaques are notable for their arched, intermediate-
size tails that are bare, or nearly bare, at the end (i.e. pig-
like), from which their common name derives. Southern
pigtail macaques (M. nemestrina) have olive brown fur
with white fur on their undersides. The fur of northern
pigtail macaques (M. leonina) is golden brown with streaks
of red fur extending from the outer edges of the eyes to the
ears. Behavioral studies of free-ranging pigtail macaques
have only been conducted on southern pigtail macaques
and the taxonomic status of pigtail macaques in captivity
whose behavior has been studied is problematical (
Groves,
2001
).
in 1989,
numbered only 3000 animals.
They are smaller than rhesus macaques, exhibit
moderate sexual dimorphism in body length and size, year-
round estrus, blue-grey pelage, a hairless, pink face, large
cheek pouches, and a hairless grey-yellow forehead. Black
hands and legs explain their pseudonym “black limbed
monkeys.” They sport tails almost as long as their body
length, in stark contrast to Japanese macaques; the tails
have an olive colored base, grey tip, and black stripes in the
middle. This species was introduced to Japan where they
have naturally hybridized with Japanese macaques
(
Kawamoto et al., 2005
).
Bonnet Macaques
Bonnet macaques (Macaca radiata) have golden to brown
bodies with black ears and lips and tails whose length is
approximately two-thirds of their body length. Females
have red faces. This species gets its name from the char-
acteristic long tuff of hair emerging from the tops of their
heads, resembling a bonnet. Two subspecies are recog-
nized, the more northern variety (M. r. radiata) being the
most widespread. The southern subspecies (M. r. diluta),
restricted to the districts of Karala and Tamil Nadu, is
smaller and paler in pelage, especially on its underbelly,
and its “bonnet” is longer and more yellow. Bonnet
macaques exhibit less sexual dimorphism and more affili-
ative relationships than other species of macaques.
Baboons
Baboons are among the largest of the Old World monkeys.
Excepting humans and the great apes, the baboons are
exceeded in size only by the mandrill and the drill, which
were once, but no longer, included within the genus Papio.
The large size of baboons suits them for use in certain
experiments requiring surgical procedures (
Nyachieo et al.,
2007
). They exhibit fewer aggressive behaviors than rhesus
and, unlike rhesus, are only moderately susceptible to
tuberculosis.
They have sharply sloping, dog-like muzzles, relatively
short tails, exhibit marked sexual dimorphisms, and live in
highly socially structured groups. The baboon taxa are
differentiated by color and size. P. papio is the smallest of
the baboons while P. ursinus is the largest. P. ursinus have
dark brown-gray hair. P. papio, P. cynocephalus, and
P. anubis get their common names (red, yellow, and olive
baboons) from their reddish-brown, yellowish-brown, and
olive colored pelage, respectively.
The earliest taxonomies of genus Papio were based on
morphology and behavior and were not consistent with
those based on subsequent genetic studies. The unusual
behavior (e.g. harem social structure) of P. hamdryas led it
to be taxonomically distinguished from the other taxa,
but molecular studies have led to revisions of this view
and to the consideration of the five major varieties as
different species (
Groves, 2005; Zinner et al., 2009
). This
Japanese Macaques
Japanese macaques are medium size macaques with naked,
pink faces and rumps, relatively short tails (one-quarter
their body length), and a thick coat of fur from gray to
brown in color. Males and females exhibit a marked degree
of sexual dimorphism with respect to size. Both body size
and thickness of fur exhibits a clinal distribution relative to
latitude and average daily temperature, with animals in the
northern extreme of their range being larger and having
thicker fur, in compliance with Bergmann's rule. Two
subspecies, M. f. fuscata and M. f. yakui, are recognized, the
latter being restricted to Yakushima, off the southwestern
coast of Honshu, and classified as endangered. Their
learned behaviors of washing wheat and sweet potatos
before consuming them, bathing in hot springs, and rolling
snowballs have all been the subject of considerable
behavioral research.
