Activity patterns, habitat use and mortality risks of mangabey males living outside social groups

W. Olupot et Pm. Waser, Activity patterns, habitat use and mortality risks of mangabey males living outside social groups, ANIM BEHAV, 61, 2001, pp. 1227-1235
Citations number
Categorie Soggetti
Animal Sciences","Neurosciences & Behavoir
Journal title
ISSN journal
0003-3472 → ACNP
Year of publication
1227 - 1235
SICI code
Isolated individuals of most species are thought to be at a higher risk of mortality from starvation and predation than those in groups. However, supp orting evidence remains scant. As part of a broader study of grey-cheeked m angabey, Lophocebus albigena, dispersal in Kibale National Park, Uganda bet ween October 1996 to February 1999, we investigated starvation and mortalit y risks within a sample of 27 radiotagged mangabey males. Each male was con tacted on average three times a week to collect data on spatial relations, habitat use, activity patterns and fates. We assessed risks by comparing da ta from 'isolated' (greater than or equal to 200 m from the group) males wi th data from 'within-group' males. We assessed starvation risks by comparin g proportions of time spent in feeding, foraging and moving, comparing rate s of movement during focal samples, and comparing proportions of time that males spent in different habitat types and canopy levels. We assessed morta lity risks by comparing scanning rates and mortality events of within-group and isolated males. Isolated males spent significantly more time scanning, but we could detect no other significant differences in time allocated to different activities by the two categories of males. Nor could we detect di fferences between within-group and isolated males in the use of habitat typ es and canopy levels. At least three of five established mortality events i nvolved males known to be isolated from groups. Given that males were found isolated only 11% of the time, it is estimated that isolated males were at least 12 times as likely to die as within-group males. These results sugge st that dispersing males may not face increased risk of starvation, but are at higher risk of mortality (primarily through predation by eagles) than n ondispersing males. (C) 2001 The Association for the Study of Animal Behavi our.