MALE JUVENILE - A BASIC UNIT OF AN ALL-MALE BAND IN HANUMAN LANGUR, PRESBYTIS ENTELLUS (DUFRESNE, 1797)
L.S. RAJPUROHIT *
DEPARTMENT OF ZOOLOGY, UNIVERSITY OF JODHPUR JODHPUR-342001, INDIA.
*Author to whom correspondence should be addressed.
Abstract
Male replacement or the change of resident adult male is one of the most important social changes, periodically seen in the bisexual troops of Hanuman langurs, Pentellus. The new resident male usually does not tolerate the presence of weaned males in his troop. After taking over, the new leader male becomes extra aggressive and punitive towards the weaned male infants (juveniles). These juvenile males quit their natal troops under stress and try to mingle into the male band available nearby, as they are the basic units of all-male bands. In 60 percent of the observed cases it was found that these males prefer to follow their fathers, who had either formed new male band or joined a band in the neighbourhood on their being dislodged. It has been observed that expulsion of juveniles, follows the disloding of the alpha, which in some cases was found to follow in quick succession. Expulsion takes place between the age of 18-42 months, with an average of 30 months (sample has 91 cases). In this sample, 80 males from different troops were successfully integrated in different male bands. The remaining 11 juvenile males disappeared in the process of expulsion and integration. It seems that the choice of young males to join a particular all-male band is linked to their survivality.