The white-nosed coati, Nasua Mai ica, is a common Neotropical carnivor
e with a social structure of band-living adult females and solitary ad
ult males. A coati population on Barro Colorado Island, Panama, was st
udied over a four-year period by mark-recapture radiotelemetry, and di
rect observation of habituated individuals. The population density was
approximately 51.5 individuals/km(2) and the sex ratio was 1:1. Band
size varied from six to 26 individuals (mean = 15.3) with extensive fl
uctuation within and between years. Mean foraging group size was small
er (7.2 individuals) than population group size, and fluctuated with f
ood availability, synchronous parturition, and the emigration of matur
e males. Mean home-range size of six bands was 0.33 km(2), and ranges
of adjacent bands overlapped from 0-66%. One band fissioned during the
study; however, the resulting bands did not disperse from the origina
l home range. Seven adult males had a mean home-range size of 0.37 km(
2), each extensively overlapping the home ranges of several other male
s. Observations of 10 adult males whose natal bands were known indicat
e that when males disperse they do not simultaneously leave the band's
home range. Rather, their home ranges remain within or broadly overla
pping those of their natal bands. This dispersal pattern is unusual wi
thin the order Carnivora.