The Fauna of British India, including Ceylon and Burma/Mammalia/Class Mammalia/Subclass Eutheria/Order Primates/Suborder Anthropoidea/Family Simiidæ/Genus Hylobates/Hylobates lar
2. Hylobates lar. The white-handed Gibbon.
- Homo lar, L. Mantissa, App. p. 521 (1771).
- Hylobates lar, Illiger, Prod. p. 68 (1811); Blyth, Cat. p. 5; id. Mam. Birds Burma, p. 1; Tickell, J. A. S. B. xxxiii, p. 196; Sclater, P. Z. S. 1870, pl. v, f. 1; Anderson, An. Zool. Res. p. 5; id. Cat. p. 28.
Myouk-lwai-gyau, Burmese; Ungka étam, Malay.
The skull is shorter in proportion to its length than that of H. hoolock. The orbital ridges in H. lar are more prominent, the muzzle shorter, the nasal orifice less elongated, the teeth smaller, and the palate shorter.
Colour. Black to fulvous or yellowish white, the back sometimes lighter than the lower parts, occasionally much variegated. Hands and feet always pale-coloured, usually white or yellowish white above. There is generally around the nude face a white ring of hair, comprising frontal band, whiskers, and beard; but the development of the ring varies, and in some specimens it is almost obsolete. Naked skin of the face black. According to all accounts, this species is much more variable in colour than H. hoolock, and pale-coloured specimens are far commoner, in some localities predominating.
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Fig. 2.—Hylobates lar. (From a drawing by Col. Tickell.)
Dimensions. An adult male, according to Tickell, measures from crown to rump 19·6 inches, fore limb 25 (humerus 9·5, radius 9·5, hand 6), hind limb 19·5 (femur 7·5, tibia 7·5, foot 4·5). The height, when standing erect, is about 30 inches; some are said to be larger. Females are smaller than males. An adult skull is 4·15 inches long from the occiput, 3·05 from the foramen magnum, 2·95 broad.
Distribution. The white-handed Gibbon is found in Tenasserim in the forests skirting the hills up to an elevation of 3000 or 3500 feet above the sea, and throughout the Malayan peninsula. Tickell says that it ranges as far north as the northern limit of Pegu, but not west of the dividing range between Pegu and Arakan; whilst Anderson states that it is found both in Arakan and Lower Pegu. I doubt the occurrence of this species in the latter countries, and I can find no satisfactory evidence of its existence in the Irawady or Sittoung valleys, although it very probably inhabits the hills east of the Sittoung. Farther information as to the range of H. lar and H. hoolock in Burma is desirable.
Habits. The white-handed Gibbon is said by Tickell, who observed both species in their native forests as well as in captivity, not to be nearly so light and active as the Hoolock, and to walk less readily. The voice, too, is quite distinct, according to the same observer, in the two species. The cry of H. lar has been rendered in musical notation by Tickell, who has given, in the paper quoted above, an admirable account of the animal's habits. It is usually found in parties of from 6 to 20, composed of individuals of all ages.
The present species is said to drink by scooping up water in its hand, and not as the Hoolock does. So entirely does it depend on its hands for locomotion amongst trees, that it carries anything in its feet. Tickell, from whom I take these details, says that he has seen a party of H. lar escape thus with their plunder from a Karen garden in the forest.
In all other respects the habits of this species, so far as they are known, resemble those of H. hoolock. The young, almost always one in number,—twins being as rare as amongst human beings,—are born in the early part of the cold season, and each sticks to the body of its mother for about seven months, after which it begins gradually to shift for itself.
According to Helfer (J. A. S. B. vii, p. 858), the Siamang (Hylobates syndactylus) is found in Southern Tenasserim; but several of Helfer's identifications were incorrect, and as no one has since heard of the animal in the Tenasserim provinces, I agree with Blyth in believing that Heifer must have been mistaken. The Siamang is larger than the other species of Gibbon, standing about 3 feet 2 inches in height, and is perfectly black in colour throughout. It is doubtful if the Siamang occurs elsewhere than in Sumatra, though Wallace states that it is found in the Malay Peninsula, where the only species, except H. lar, noted by Cantor (J. A. S. B. XV, p. 173) is H. agilis. In Siam H. leucogenys (figured P. Z. S, 1877, pl. lxx) is said to occur.
At the same time there appears to be a large, not yet identified, Ape in the mountains of Tenasserim, but whether it belongs to the anthropoid Apes, or is a large tailless or nearly tailless Macacus, it is impossible to say. The only observers who have seen this animal, so far as I am aware, are Mr. W. Davison and Captain C. F. Bingham. The former writes to me that when collecting birds for Mr. Hume, on Muleyit, a mountain about 7000 feet high, east of Moulmain, he came suddenly on a number of Monkeys feeding on the ground in a very dense part of the forest. He had a good look at one standing erect about 10 feet away, and considered it too large for a Hylobates, as its height was about 4 feet. It was, in front, of a deep ferruginous colour, and as it moved away it was distinctly seen to be tailless. Mr. Davison does not remember the colour of the back, but thinks it was the same as that of the underparts. He had only a half-charge of the smallest shot in his gun, so did not fire, and he never saw any of these animals again.
Captain Bingham informs me that a specimen was brought to him in the flesh (but unfortunately so decomposed that only the skeleton could be preserved) of a tailless female Ape, with long grizzled red hair on the outside of the limbs, and standing about 3 feet 6 inches high. This was near the place, Muleyit, where the animals above mentioned were seen by Mr. Davison. The skeleton was subsequently lost or mislaid. The same observer once saw a party of four or five large tailless monkeys at the foot of Muleyit, but these appeared to be black in colour. None of the animals resembled Gibbons.
Both Mr. Davison and Captain Bingham are excellent observers. The only known animal corresponding with their descriptions is the Ourang-outang, but so well-known a form would have been recognized by others. It is perhaps more probable that the animal seen may have been a tailless, or nearly tailless, Macacus.