Butterfly counts at Casuarina Coastal Reserve in the seasonal tropics of northern Australia

Seasonal rhythms underlie most ecological phenomena, but the seasonality of butterfly assemblages in the monsoonal tropics of the Top End of northern Australia remains unquantified. I counted butterflies along a 2.9-km transect through the Casuarina Coastal Reserve near Darwin in northern Australia on 23 occasions during eight census periods over a 14-month period. Both the number of taxa and number of individuals peaked during the wet season, but the latter peak continued into the early dry season. The dry season troughs in activity were about 50% by taxa and 35% by number compared with wet season peaks. Eight taxa demonstrated clear seasonal peaks, four in the wet season, two in the late wet - early dry season and two in the dry season. Much remains to be learnt about the seasonality of butterflies in the Australian monsoon tropics.