Abstract # 96:

Scheduled for Friday, June 20, 2008 05:00 PM-07:00 PM: Session 12 (Ball Rooms A and B) Poster Presentation

Demography of Alouatta pigra in threated habitat in south-eastern Mexico

Y. M. Bonilla-Sanchez1,2, J. C. Serio-Silva2, G. Pozo-Montuy1,2,3 and N. Bynum4
1Instituto de Neuroetologia-Universidad Veracruzana, Xalapa, Veracruz 91000, Mexico, 2Instituto de Ecologia A.C. Departamento de Biodiversidad y Ecologia Animal, Xalapa Veracruz, Mexico, 3Universidad Juarez Autonoma de Tabasco, 4Center for Biodiversity and Conservation, American Museum of Natural History, New York, USA.
     It has been suggested that agricultural practices and extensive cattle ranching are some of the main causes of fragmentation and habitat loss in the southern of Mexico. Under these conditions the black howler monkey (Alouatta pigra) has been considered as endangered in our country. For this reason, we evaluated the populations and habitat threat of Alouatta pigra in Playas de Catazajá, Chiapas, Mexico. During 2004 - 2006, field work was done to obtain population and habitat data for A. pigra, and a geographical information system was used to determine the habitat thereat variables (area, distance to nearest human settlements and roads) in 70 fragments surveyed (6.39 km2). Our results show different pressures on the disappearance of the fragments of the natural landscape (high=24.3%, medium=75.7%, low=0.0%). Population size was 659 individuals with a mean troop size of 5.0 ± 2.3 ind. We found adult male:female ratio of 1:1.4, adult female:juvenile was 1:0.6 and adult female:immature was 1:0.8. Adults make up 66% of the population, juveniles 21% and infants 13%. In conclusion, most of the fragments are inhabited by troops of howler monkeys, but most are also threatened. It is necessary to protect these sites through activities that pressure humans to decrease deforestation rates in the study area. Financed by Instituto de Ecología A.C and IDESMAC, A.C.