Butterfly wing colour patterns and flying heights in the seasonally wet forest of Barro Colorado Island, Panama

Abstract

ABSTRACTI investigated the extent to which adult butterflies with different wing colours display preferences for flying heights within a lowland tropical forest. Observations on eight colour groups, some of which comprised putative aposematic models and mimics while others contained nonaposematic species, were made from the forest floor and from a scaffold tower that reached above the canopy. Two groups (yellow pierids and papilionids and orange heliconiines) were most frequently observed in or above the canopy, and other groups were most frequently observed in or below the canopy. The evidence suggests that significant differences exist between some groups, but stratification does not occur among all colour groups. In particular, flight distributions of some mimicry rings overlap considerably. The light environments of different forest layers are variable, and the role that butterfly wing colours play in signalling or avoiding prcdation is little understood. However, the general lack of fine stratification of colour groups suggests that flight preferences do not occur because wing colours and patterns are especially cryptic against the background of particular forest layers.