Yellow-cheeked crested gibbon
- One of the rarest gibbons.
- Females give birth to one young every 2–3 years.
- The yellow-cheeked gibbon sings duets in the morning.
- Males and females have different colouring.
- Lives in monogamous pairs.
- Long arms for brachiation.
- Inhabits Vietnam, Laos and Cambodia.
- Strictly arboreal.
- Feeds on fruits and leaves.
- Status Endangered.
Age
Gabriella's crested gibbon typically lives for 25 to 35 years, with a maximum lifespan of 48 years; the theoretical lifespan ranges from 22 years and 1 month to 40 years and 8 months. The species reaches sexual maturity between 6 and 9 years of age, and the young are born with their eyes open. During the embryonic stage, the embryo develops inside the mother. The infant stage begins immediately after birth, where the young drink milk from the mother and live with their parents in trees for a duration of 1 to 2 years. Following this, the adult stage commences, lasting from 7 to 35 years, during which the gibbons live in family groups, sing songs, and forage for food.
Phenotype
The yellow-cheeked hoolock gibbon has black fur all over its body and bright yellow cheeks, as well as light beige-orange fur with a black crest where a tuft of hair on the head forms a noticeable ruff. Adult individuals have very long forelimbs, allowing them to swing quickly between trees. The infant is covered in light fur and clings tightly to its mother.
Physiology
The body height of Gabriella's crested gibbon ranges from 17.8 centimeters to 4.5 meters, with body length varying from 45 to 60 centimeters and mass ranging from 5 to 7.5 kilograms; the embryo stage presents individuals with a body mass from 1 to 80 grams and a body length from 1 millimeter to 5 centimeters, while the infant stage features individuals with a body mass from 300 grams to 1.8 kilograms and a body length from 20 to 40 centimeters; the adult stage has a body mass from 5 to 7.5 kilograms and a body length from 45 to 60 centimeters.
Habitat
Gabriella's crested gibbon inhabits areas up to 1.5 kilometers above sea level, living in tropical dry forests characterized by heat and a dry season with deciduous trees, and also in tropical moist forests that are consistently hot and humid with large trees and vines. The species occupies terrestrial landscapes and the forest canopy. The climate is always hot and wet, with very high temperatures and humidity year-round and rain nearly every day; summers bring heavy rains, while winters have little precipitation; it is always hot throughout the year, with frequent rains but occasional dryness; and in summer there are abundant rains, while in winter there is almost no precipitation.
Shelter
Gabriella's crested gibbon inhabits the crowns of tall trees and does not have a permanent or long-term shelter. The species does not use any fixed or lasting refuge, and therefore lacks a specific shelter. The sole purpose of the available locations is for rest.
Geography
The Gabriella's crested gibbon is found within the Indomalaya biogeographical region.
Feeding
Gabriella's crested gibbon primarily eats ripe fruits and also consumes young leaves, flowers, and occasionally small insects; the species gathers food by hand from trees, with its diet including fruits, leaves, flowers, insects, nectar, and seeds. The search for and acquisition of food constitutes the species’ feeding strategy, and the daily food requirement ranges from 200 grams to 450 grams. The species preys on two-winged insects, beetles, butterflies, membranous insects, bedbugs, straight-winged insects, dragonflies, mayflies, and net-winged insects.
Reproduction
Gabriella's crested gibbon is a terrestrial species that lives and develops on land, away from bodies of water, and young develop in nests built on the ground or close to it, as well as high in the branches of shrubs or trees. The species reproduces through live birth, with the female giving birth to one offspring after a gestation period of seven months; the male and female form a lasting pair. The mother carries the young on herself for two years, and the size of the litter is one. Sexual reproduction occurs through homogamy, always involving fertilization without generational change. The species reaches maturity from six to nine years of age, and the interval between births is from two to three years.