Biology 3436F/G Lecture Notes - Lecture 4: Surili, Estrous Cycle, Sept

• School: Western University
• Department: Biology
• Course: Biology 3436F/G
• Professor: Graham Thompson

Document Summary

Dissecting the adaptive significance of behaviour: a case study. Langurs live in social groups of mostly females and usually one dominant, breeding male. Females live in long term stable groups and are related together. Females reproductive life time is pretty long, shared maternal care in these groups. At age, young males leave their natal group, form packs of mostly unrelated males, and become nomadic until they can usurp a dominant to join a group of breeding females. Fe(cid:373)ale al(cid:449)ays has a reside(cid:374)t (cid:373)ale, so the (cid:373)ale that(cid:859)s tra(cid:448)elli(cid:374)g that (cid:449)a(cid:374)ts to take o(cid:448)er has competition. When males join a group of females for the first time (invade), dispense older male that (cid:272)a(cid:374)(cid:859)t defe(cid:374)d hi(cid:373)self, they kill old pups. Not good for his own species to do that. Females go into false estrous (cid:374)ot o(cid:448)ulati(cid:374)g (cid:271)ut gi(cid:448)e (cid:272)ostly sig(cid:374)al that they(cid:859)re o(cid:448)ulati(cid:374)g. When males do join a group, three things can happen: infanticide by males, post-(cid:272)o(cid:374)(cid:272)eptio(cid:374) or (cid:858)false(cid:859) estrous (cid:271)y females.