Spatial and temporal patterns of territorial mate locating behaviour in Hypolimnas bolina (L.) (Lepidoptera : Nymphalidae)

Male Hypolimnas bolina (L.) (Lepidoptera: Nymphalidae) defend perch sites a s a method of visually locating receptive females. In this study we charted the spatio-temporal activity of perching males in tropical Australia to in vestigate (a) the extent to which male activity is thermally constrained, a nd (b) the physical attributes of selected perching sites. Butterflies were surveyed along two 5-15 m wide open corridors through dense vegetation, an d this allowed the prediction that males should favour narrower corridor se ctions in order to maximize their visual search capability. This prediction was supported. Beyond corridor width, the distribution of favoured perches was not explained any further by patterns of shading, larval food plant di stribution, or the presence of nectar resources. Males were active from 080 0 to 1700 h. but the number of perching individuals varied throughout the d ay, and this pattern varied between the two transects. Most individuals per ched along one transect in the morning (0900-1100 h), whereas activity alon g the other peaked around midday (1100-1300 h). This between-transect diffe rence in male activity followed changes in shading between the transects, h owever this variable did not predict male distribution at the territory sca le. Although ambient and black body temperatures were significantly related to population-level activity. these variables only predicted 15-55%, of th e variance in male counts in individual transects. This result, viewed in c onjunction with the limited available information on female receptivity, su ggests that the timing of mate location in H. bolina may be primarily influ enced by the daily pattern of female availability.