Mr. Sanchezvillagra et al., RELATION OF INTERGROUP VARIATION IN ALLOGROOMING TO GROUP SOCIAL-STRUCTURE AND ECTOPARASITE LOADS IN RED HOWLERS (ALOUATTA-SENICULUS), International journal of primatology, 19(3), 1998, pp. 473-491
We compare the allogrooming behavior of 5 troops (average size = 8.2)
of red howlers (Alouatta seniculus) from the Venezuelan Llanos with th
at of other A. seniculus and Alouatta spp. of the genus. lit 126.9 obs
ervation hr, we recorded 118 allogrooming events, with an average bout
length of 109 sec. Females groomed more frequently than males did, bu
t as groomees there is no significant differences between sexes. Adult
males groomed adult females mostly in a sexual context (before copula
tion). Allogrooming rates differ significantly among groups. There are
also significant differences among members of the same troop both as
groomers and groomees, which we explain in the context of the social b
ehavior and history of each troop. There is no significant correlation
between weight of the groomee and duration of the grooming bout. Howe
ver, the examination of grooming rates and ectoparasite load suggests
that allogrooming may have hygienic consequences. Differences in allog
rooming rates among species of Alouatta are related to differences in
group kin structure and patterns of female competition in particular c
oalition formation. We conclude that the social structure and the degr
ee of relatedness among individuals within a group (or among individua
ls in a population in interpopulation comparisons) is a more important
determinant of allogrooming rate than body size or group size. Our re
sults emphasize the importance of considering intergroup and interpopu
lational variation in behavior.