The Hanuman Langur is an Asian monkey; whose social behavior is
uncanny. Their troops consist of both males and females numbering around 125.
The head male—of a troop where there is one male—is competing with other males
to maintain his position as leader. When a group of males overthrow the leader
—so to speak—they kill his offspring. After that “ritual” one male becomes they
new leader. That male then mates with the females of the troop and the process
is repeated. The males gain a reproductive advantage because the females are at
their maximum sexual receptivity when they lose their offspring.
· This species is vulnerable to infanticide.
· Males attack the infants only if they were not present at the time of contraception.
· The males are usually protective of their offspring, however some still kill their own young.
· Ecology pressures that influence sex ratio populations also affect group size and social structure.
· Increasing the Hanuman Langur troop size might prevent takeover and infanticide.
Because the social behavior of the Hanuman Langur depends on ecology...ecological evolution impacts the behavior. The ecology of the Hanuman Langur includes varied troop sizes and varied troop constituents, which evoke different behaviors. As previously stated, troop size impacts the level of infanticide.
Questions for Research
What does the social behavior of hanuman langur imply about evolutionary desires to be a leader or at an advantage by any means?
What does this behavior say about evolution in general?
Hanuman Langur selectivity and evolution…