This page was done as part of an assignment
for Animal Behavior at Davidson College.
Mating System
Howler monkeys exhibit female defense
polygyny and the mating system is characterized as a harem system.
The food that the howlers eat is too abundant for the males to defend for
female consumption so they keep the females from associating from other
males. Each troop of howlers may contain one or several males, but
the multi-males troops are essentially unimale because only the dominant
male has access to the females(Smuts et al. 1987). He usually fathers all
of the offspring (Smuts et al. 1987). The hierarchy between
males is not linear because there is one dominant male over all the other
males. Births occur all year long and there is usually 1-2 years
between births (Smuts et al. 1987). Mature males emigrate and leave
the troop and some females may emigrate to avoid female/female competition(Smuts
et al. 1987). Most females do remain in their natal group however(Smuts
et al. 1987). Extra-pair copulations have been observed in some species.
Male/Male Relationships
There is much competition between males. Male takeovers of troops are common and large wounds on the male bodies are common as a result of fighting. Some troops can be described as age-graded because one male does most of the breeding and he is related to all the males that are younger than him (Smuts et al. 1987).
Female/Female Relationships
Researchers suggest that females
howlers can control the size of the troop if certain females are reproductively
repress other females and thus do not allow them to breed(Smuts et al.
1987). Although complete repression has not been observed.
Offspring/Parental Relationships
A new infant becomes the attention of several females in the troop especially those without offspring (Smuts et al. 1987). For the first 5 weeks, an infant clings to the mother and, at 10 weeks it begins exploratory feeding (Smuts et al. 1987). Male infanticide occurs when a new male takes over the troop. Infanticide reduces time between births so that the new male can mate with the resident females.
This page was done as part of an assignment
for Animal Behavior at Davidson College.