A Social Monogamy, Extra-Pair Paternity, and Dispersal in the Large Treeshrew (Tupaia Tana)

Article excerpt

Monogamy occurs in only 5% of mammalian species, but is significantly more common in the Euarchonta: primates, dermopterans, and treeshrews (15% spp.). However, many of these species do not breed monogamously, indicating the need to understand behavioral and genetic monogamy as separate evolutionary phenomena. I examined monogamy in the large treeshrew (Tupaia tana) in Sabah, Malaysia using radiotelemetry data from 46 individuals tracked during and after a fruit masting episode in 1990-1991, during a non-masting period from 2002-2004, and in a selectively logged forest from 2003-2004. I show that large treeshrews exhibit behavioral monogamy in all these ecological situations. However, behavioral monogamy is best characterized as dispersed pair-living, or "asocial monogamy," in this species because male-female pairs travel, forage, and sleep alone on their joint territories. Next, I use microsatellites and mitochondrial DNA d-loop haplotypes to analyze the genetic maternity and paternity of 24 T. tana offspring. I show one of the highest rates of extra-pair paternity (EPP) ever recorded for a behaviorally monogamous mammal. Over 40% of young were sired by males that were not the behavioral partner of their mother, and three litters exhibited evidence of multiple paternity. …