THE ANIMAL FILES

Northern white-cheeked gibbon

Nomascus leucogenys

The same young gibbon changes coats more than once.

Northern white-cheeked gibbons have striking adult sex differences, but both sexes begin life in pale coats. Long arms support canopy travel, fruit supplies much of the diet, and coordinated male-female songs are a prominent feature of group life.[1]

Follow the evidence ↓
Northern white-cheeked gibbon
Image: Bilby · Commons · CC BY 3.0
Changing coats
Both sexes are pale at birth.[1]
Arms in the canopy
Arms are longer than legs.[1]
Duets and other calls
Male and female contributions differ.[1]

Changing coats

Young have yellow-buff fur, then pass through a dark stage with pale cheeks. Adult males are largely black with white cheek patches; adult females are reddish tan with a dark crown area. One youthful coat does not predict adult sex by colour alone.[1]

Arms in the canopy

Elongated arms aid movement among branches. The species is arboreal and active by day, taking fruit with leaves, buds, flowers and some small animal food. It sleeps on high branches rather than using a ground burrow.[1]

Duets and other calls

Duets combine distinct male and female sequences, while solo calls and occasional juvenile participation are also described. Males can produce booming sounds using a throat sac. Vocal differences are useful alongside the appearance of closely related gibbon species.[1]

A COMMON MIX-UP

Are all white-cheeked gibbons black with white cheeks throughout life?

No. Colour changes with development, and adult females have a different coat from males.[1]

TRY A LITTLE REASONING

Why does a dark juvenile's coat alone not settle its eventual adult appearance?

Reveal the explanation

Both sexes pass through a dark youthful stage before adult sexual colour differences develop.[1]

Sources & editorial notes

Adapted and translated from the cited Wikipedia revisions, with source-linked reasoning. Image credit and licence are listed separately above.

Adapted and translated from Wikipedia contributors; exact revisions are linked below. CC BY-SA 4.0

  1. Wikipedia contributors — Northern white-cheeked gibbon (cited revision)
  2. NCBI Taxonomy — Nomascus leucogenys

Last fact check:

One discovery leads to another

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