Meeting Abstract

33.4  Jan. 5  Size Matters: Male mating tactics in a prosimian primate, slender loris Loris tardigradus KAR GUPTA, K*; KATTI, M; Arizona State University; California State University kaberi@asu.edu

Nocturnal prosimian primates have been used as models to understand early evolution of primate social systems, but their social and mating systems are poorly understood. While simian primates exhibit diverse and complex mating systems with distinct male tactics, viz., mate guarding, territoriality, and sperm competition, prosimians are often viewed as having simple polygynous mating systems. We challenge this view by showing that male slender lorises Loris tardigradus, a small little known prosimian, employ a complex conditional mating strategy incorporating the alternative tactics of roaming and sneaking or territory and mate guarding. We studied the slender loris, a little known nocturnal prosimian, in Kalakad-Mundanthurai Tiger Reserve (KMTR), the southernmost protected area in peninsular India, during June�December 1998 and July 2002�June 2003. We captured, marked with radio-transmitters and focal followed 40 individuals in 10 square km area. We demonstrate that these tactics are mediated through body condition and testis size, resulting in three male types�roamers, settled bachelors, and settled paired. Settlers are in better body condition than roamers. Among settlers, paired males have larger testes than bachelors, suggesting a role for both sperm competition and mate guarding. This study, like other recent work, refines our understanding of prosimian mating systems. Instead of polygyny, lorises show a complex mating system that combines pair living, elements of polygyny, and sperm competition�an unusual combination among primates�and a conditional male mating strategy with alternative tactics.