Habitat fragmentation and population size of the black and gold howler monkey (Alouatta caraya) in a semi deciduous forest in northern Argentina.

G.E. ZUNINO, M.M. KOWALEWSKI, L.I. OKLANDER, V. GONZALEZ

AMERICAN JOURNAL OF PRIMATOLOGY

Wiley InterScience

Año: 2007 vol. 69 p. 966 - 975

0275-2565

A population of black and gold howler monkeys (A. caraya) living near the southern limit of its distribution was studied in 2003 in a semideciduous forest located in northern Argentina to evaluate the effects of habitat fragmentation due to logging. Aerial photograph taken in 1982, 1992, and 2001 were used to compare maps of vegetation. These maps were used to evaluate changes in the area covered by forest fragments. From March to June 2003 10-day monthly surveys of howlers were made in each fragment. A total of 233 individual howlers were counted, belonging to 34 groups plus a solitary adult female. Groups ranged from 2 to 19 individuals (average=6.82), and 23.5% of the groups contained more than one adult male. Adults accounted for 55% of the individuals, immatures for 45%, and infants represented 13% of the total. Data obtained were compared with information available for the same population for 1982 and 1995. Results revealed no changes in the area of fragments, or the density. Group sizes and group composition of howlers suggest that the population remained stable over the past twenty-two years. The ecological density appears not to be affected by fragmentation and logging, but crude density was low compared with other less-disturbed habitat. The status of the population remains uncertain due isolation, and there are no protected areas to ensure its stability for the future.