Perching in an assemblage of Scarabaeinae in forest of French Guiana

Perching was a common behaviour among the species of an assemblage of Scarabaeinae in a pristine forest in French Guiana. Forty three perching dung beetles were recorded during 7 years sampling. Small diurnal tunellers (mean size 7.0 mm) dominated on isolated leaves, around defecations of Howler monkey or human feces, at an average height of 62.8 cm. Perching height were positively correlated with body size except for five large species, of which three possessed chemical defense. Two mimetic complexes were identified. Aggregation away from any resource was shown. Monkeys' defecations attracted many dung beetles including several arboreal Canthon (Glaphyrocanthon) forming dung balls on leaves. Other species were perching to wait to meet a sexual partner or perform kleptoparasitism. Olfactory signals seemed to play a role in various perching situations. Competition and predation may be the major constraints in perching.