The Arboreal Ant Mosaic in Two Atlantic Rain Forests

Abstract

Using the "canopy raft" and the "canopy sled," two techniques permitting direct observation and sampling, we studied the arboreal ant mosaic in two equatorial Atlantic forest canopies, one in Cameroon, the other in French Guiana. In both cases, 167 individual trees were sampled. The trees sampled in Cameroon (29 families; 63 species) were occupied by only three dominant ant species: Oecophylla longinoda and two Cremato gaster species, one of them occupying 88.6% of the trees. Camponotus brutus, a sub-dominant species, was recorded on three out of eight trees unoccupied by dominants. The trees sampled in French Guiana (35 families; 90 species) were occupied by 43 dominant and/or sub-dominant ant species, with five dominants noted more frequently than the others: Azteca instabilis (19.2% of the trees), Cephalotes atratus (10.8%), Cremato gaster limata parabiotica, Á. chartifex, and Dolichoderus quad ridentìculatus (9.6% each). The most frequent subfamily of ants was the Myrmicinae in Cameroon (89.2%), and the Dolichoderinae in French Guiana (53%). In Cameroon, trees were noted to be occupied by two or three dominants (i.e., co-dominants), while this situation represented 29.4% of the Guianian trees.