Population status and identification of potential habitats for the conservation of the Endangered black howler monkey Alouatta pigra in northern Chiapas, Mexico

Yadira M. Bonilla-Sáncheza1, Juan Carlos Serio-Silvaa2 c1, Gilberto Pozo-Montuya1 and Nora Bynuma3

a1 División de Posgrado, Instituto de Ecología AC, Xalapa, Mexico

a2 Departamento de Biodiversidad y Ecología Animal, Instituto de Ecología, AC, Apartado Postal 63, Xalapa, Veracruz 91000, Mexico.

a3 Center for Biodiversity and Conservation, American Museum of Natural History, New York, USA


In the Mexican state of Chiapas the rainforest has been cleared, to make way for crops and extensive cattle ranching, at an annual rate of 12.4% since 2002. The conservation status of the Endangered black howler monkey Alouatta pigra in these fragmented landscapes in north-eastern Chiapas has not previously been examined. We therefore surveyed A. pigra populations in the municipality of Playas de Catazajá during 2004–2006 to obtain population and habitat data for this species in 115 fragments of remnant vegetation. A geographical information system was used to determine the variables (fragment size, and distances to the nearest fragment, human settlement and water body) that could be used to generate an index of habitat potential for A. pigra. We estimated a population of 659 individuals and a mean troop size of 5.0 ± SE 2.3. The adult male : female ratio was 1 : 1.4, the adult female : juvenile ratio 1 : 0.6 and adult female : immature ratio 1 : 0.8. The index of habitat potential indicates that 12% of the fragments have a high conservation potential for A. pigra. This index is a valuable tool for evaluating the conservation status of this species and its habitat, and can be expanded to include additional variables, thus allowing for a more comprehensive assessment.

(Received February 20 2008)

(Reviewed May 20 2008)

(Accepted July 04 2008)