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Nomascus
About Gibbons,
Symphalangus,
Hoolock,
Hylobates
GENUS NOMASCUS
(Miller, 1933)
Crested gibbon
The crown hair of males and immature (black) females stands erect,
with
the male's hair being longer in the crown's center. The nose is long and
slender (Groves, 1972). Females have an elongated clitoris and males
have a long baculum (Groves, 1984); external genitalia of the two sexes
appear similar. Infants are pale at birth. Starting at the fingers,
toes, and face ring, infants gradually change to a black phase. Near the
age of sexual maturity, females change back to the light phase while
males remain black (Pocock, 1905; Delacour, 1951; DePutte &
Lecierc-Cassan, 1981; Liu, et al., 1989; Couturier & Lernould, 1991).
With the exception of the buff-cheeked gibbon (N. gabriellae), males
have a small throat sac.
This genus is characterized by a diploid chromosome number of 52.
Nomascus concolor
concolor (Harlan, 1826). Tonkin black-crested gibbon. Area: N.
Vietnam, between the Black and Red River, Central Yunnan.
Males are black, with crown hair growing upwards and
slightly longer in the center, with longer body hair and few white hairs at
the corner of the mouth. Females can have from buffish to a light tawny
body hair and black-brown or black occipital streak (Ma, Wang, and Poirier,
1988; Geissmann, 1989). Females have a black crown streak and dark hair on
the ventrum (Geissmann, 1995) creating an inverted triangle. Females could
also be buff-tan with black on first digits, chin, with few black hairs on
the genitals, pelvis, legs, around the ears and a creamy-buff throat.
Females have a white patch of hair above the mouth and below the eyes.
Nomascus concolor lu (Delacour, 1951). Laotian black-crested
gibbon. Area: NW Laos.
Males have a trace of grey mixed throughout the body hair.
They have been reported to have a trace of a silver streak above the
temples. However, the description of a subspecific pattern is complicated by
the inclusion of subadults undergoing color transitions (Delacour, 1951).
Two specimens that were collected at Ban Nam Khueng may be Nomascus
concolor lu. The overall pelage of the adult female is tawny-buff with
a black crown. The chest is buff with a few black hairs extending from the
chest and gradually darkening in the genital region, creating a circular
pattern. There are a few black hairs on the fingers and toes. The chin is
black with few black hairs on throat, and with a few black hairs above the
ears. The face ring is slightly lighter than the surrounding hair, and
there are no long guard hairs. The male has short black hair mixed with
longer guard hairs. Until live specimens can be studied it is questionable
if this subspecies is not Nomascus c. concolor (Geissmann, in press). |
Photo by E. Haimoff
Nomascus c. concolor adult male
Photo by T. Geissmann
Nomascus c. concolor adult female |
Photo archive Tierpark Berlin
Nomascus nasutus juvenile female and juvenile
male Nomascus leucogenys siki
Photo archive Tierpark Berlin
Nomascus nasutus infant female |
Nomascus
nasutus (Kunkel d’Herculais, 1884). Eastern
black-crested gibbon. Area: NE Vietnam, east of the Red River and southern
China.
Males and immature have blackish hair, with slightly brownish
hair on the chest, or as much as from the throat to the abdomen. Females are
a buffish to a buffish gray color with a long wide black crown streak that
can go past the nape, and extends to the brow and tapers to a thin face
ring, and becoming thicker at the chin. There is a narrow blackish brown
chest plate slightly wider than the face, beginning at the throat and
tapering at the top of the abdomen.
Article in our newsletter by Tilo Nadler
about this species. |
Photo archive Tierpark Berlin
Nomascus nasutus adult female
Photo archive Tierpark Berlin
Nomascus nasutus adult female |
Photo by Bawangling National Nature
Reserve staff
Nomascus
hainanus adult male |
Nomascus hainanus (Thomas, 1892). Hainan gibbon. Area: Hainan
Island, China
Males have short, black hair, and the crown hair is not as obvious
(Pocock, 1905; Groves, 1972; Ma, Wang, and Poirier, 1988). Females have a
black crown patch, with all other body hair being a brown-yellow, with no
black hairs on the limbs (Ma, Wang, and Poirier, 1988), and white patch of
hair above the mouth and below the eyes.
Article naming this species among the rarest primates in the world, from
IUCN. |
Photo by Bawangling National Nature
Reserve staff
Nomascus
hainanus adult female and infant.
|
|
photo by J. Zuckerman
N. l.
leucogenys adult female (left) & adult male (right)
photo by R. Agha
N. l.
leucogenys adult female (left) holding 6 month old female, with 4.5
year old male. Alan views them in the balcony of their enclosure. |
Nomascus leucogenys leucogenys (Ogilby, 1840). Northern white-cheeked
gibbon.
The male cheek patches connect under a black chin and extend up to
the
top of the ear. Females range in color from dark to light buff to creamy
orange often diffused with tan, grey, or black hairs, with a
small-to-medium-length black crown patch. Females can have brown-black
genitals and black hairs on the tips of fingers and toes. A trace of the
crown patch can extend between the scapulae. Females are sometimes
larger than are males.
Nomascus l. leucogenys
is extinct in southern Yunnan, and
nearly extinct in northern Vietnam, although they can be found in a small portion of Laos.
We currently house three pairs, one of which has two offspring.
Nomascus leucogenys siki (Delacour, 1951). Southern white-cheeked
gibbon. Area: Central Vietnam, Southern Laos.
Males have small white cheek patches that extend as far up as the
eye's
corner, and thin white hair partially encircles the upper lip and
totally encircles the lower lip, terminating in a black chin. Adult
females are more similar in appearance to adult female H. l. leucogenys
than to N. gabriellae females (Geissmann, 1995). |
photo by M. Osterholm
N. l.
leucogenys adult female
photo by R. Wirth
N. leucogenys siki
male
|
photo by A. Mootnick
N.
gabriellae adult female (left) & adult male (right) |
Nomascus gabriellae (Thomas, 1909). Buff-cheeked gibbon. Area:
Southern Vietnam, Southern Laos, Eastern Cambodia.
Males have small, light buff cheek patches that extend to the bottom
of
the orbital ridge and can be slightly separated at the throat. Females
are generally smaller than H. l. leucogenys females and have a black
fringe at the ears. Females are generally buff to strawberry-buff and
can have a very slight grizzling of darker hairs on the chest, on edges
and tips of fingers and toes, and on the outer forearm. Adult females
may have slight red-brown genital hairs, and usually there is a trace of
a white fringe encircling the face. Females are typically smaller than
males. |
About Gibbons,
Symphalangus,
Hoolock,
Hylobates
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