Abstract # 2365 Event # 88:

Scheduled for Saturday, June 21, 2008 04:30 PM-04:40 PM: Session 11 (Meeting Room 2DEF) Oral Presentation

The abundance, distribution and habitat use of the introduced patas monkey (Erythrocebus patas) population in Puerto Rico

M. Massanet and J. Chism
Winthrop University, Department of Biology, Rock Hill, SC 29733, USA
     Puerto Rico contains a population of introduced free-ranging patas monkeys (Erythrocebus patas). The only previous study of the monkeys’ ecology, in 1993, found a population of around 120 individuals living in four heterosexual groups and several all-male bands (Gónzalez-Martínez, 1998). In 2006 we carried out a follow-up study on this population using group follows and instantaneous scan sampling to collect information on the size, composition, and habitat use of heterosexual groups. Our results indicate that this population now numbers from 514 to 621 individuals living in 9 to 11 heterosexual groups. While the population’s mean group size in 1993 was 26.3 individuals, by 2006 mean group size had increased significantly to 52.21 [t-test, a=0.05]. Utilizing GPS coordinates and a GIS aerial photograph we calculated a study area of 172 km², yielding a population density of 3.02 individuals per km², three to four times higher than densities reported for African patas populations. The 2006 study showed no preference for human-altered versus semi-natural areas whereas in 1993 patas rarely used human-altered areas. This study documents rapid expansion of the patas monkey population in Puerto Rico due, we suggest, to factors such as lack of non-human predators and abundant resources. These factors may also contribute to the large group sizes seen in this population compared to patas populations studied in their natural habitats in Africa.