... Congo ...
by Infocostarica Staff

The howler is the most abundant as well as the largest of Central American monkeys. It inhabits both lowland and mountainous forests throughout Costa Rica. Fortunately it is less sensitive to habitat destruction than the spider monkey and can be found clinging precariously to existence in many relic patches of forest.

This monkey is best known for the stentorian vocalizations of the adult males. These noisy calls can be heard for more than 1km in dense forests and are frequently given at daylight and sunset as well as in answer to such stimuli as people, airplanes, rain, thunder, and other howlers. The vocalizations are believed to be a spaced instrument, and they may also help as a means of interaction within a social group.

An adult male Costa Rican howler weighs 6 to 7 kg. Adult female howlers weigh 4 to 5 kg. Adults are black with brown or blond saddles and have long guard hairs on their flanks. These protector hairs give them their common name, mantled howling monkeys. At birth infants weight about 0.4 kg and are silver to golden brown. They get the grown pelage by 12 weeks of age and begin to move away from their mothers about the corresponding time.

Alimentary analyses indicate that mature leaves that were eaten contained significantly more protein, more methioine, and lower fiber than those that were not eaten. Further, grown leaves that were eaten did not differ significantly from fresh leaves that were ingested.

It appears that the consideration group was selecting an optimal nourishment, at last in terms of maximizing entire protein and certain basic amino acids while minimizing the intake of fiber and plant secondary compounds. Faced with a extensive diversity of mature leaves the howlers can do select the best items accessible. Phenophase availability changes over the year, and this is reflected in the daily diet organization. The study group preferred new leaves and flowers to mature leaves. Consequently, while the late dry and early wet seasons when this phenophases are obtainable new leaves and flowers may constitute the whole daily diet. Similarly, during the late wet season fruit and mature leaves make up the bulk of the diet.

Alouatta palliata frequently inhabits both lowland and mountainous forests from southern Mexico to northwestern South America. In Costa Rica they are the last remaining non-human primates in several relict patches of forest.