GROOMING IN BROWN HOWLER MONKEYS, ALOUATTA-FUSCA

The grooming behavior of a group of brown howler monkeys was studied f or one year in an Atlantic forest reserve of southeastern Brazil. A to tal of 290 grooming bouts were recorded and analyzed. The two adult fe males directed most of the grooming (91%), while the adult male was th e major recipient (37%). Grooming between females, and between them an d their siblings, also occurred quite often. On average, the group spe nt 2% of its daily time grooming, with a higher frequency around noon. There were significant differences, however, in time spent grooming b etween seasons; grooming was more abundant during the coldest seasons (autumn-winter) and rarer in hotter ones (spring-summer). A significan t negative correlation was found between grooming time and temperature , but contrary to expectations, grooming time failed to correlate with both the group's diet and the demands of food-gathering, as measured by travelling time and day range length. A comparison of grooming beha vior with other species of the genus suggests that brown, red (A. seni culus), and black howler monkeys (A. caraya) are more similar to each other than to mantled howlers (A. palliata), a result that probably is linked with the differing social structure and group size of the latt er species. (C) 1995 Wiley-Liss, Inc.