Demography and mobility of three common understory butterfly species from tropical rain forest of Papua New Guinea

The mobility of butterflies determines their ability to find host plant species, and thus their potential host plant range, as well as their ability to maintain meta-populations in fragmented habitats. While butterfly movement has been extensively studied for temperate species, very little is known for tropical forest species. A mark-release-recapture study of the three most common butterfly species in the understory of a lowland primary rainforest in Papua New Guinea included 3,705, 394 and 317 marked individuals of Danis danis, Taenaris sp. and Parthenos aspila respectively, with 1,031, 78 and 40 butterfly individuals recaptured at least once. Over a period of 6 weeks there were almost 22,000 individuals belonging to these three species hatching within or entering our four study plots totaling 14.58 ha in area. The most abundant species, D. danis, with 20,000 individuals, showed highly variable population densities during the study. The residency time in the studied plots was highest for P. aspila (84 days), as individual butterflies stayed mostly in a single gap; we estimated that less than 1 % of individuals disperse 1 km or more. Similar movement probability was found in D. danis whilst in Taenaris sp., 10 % of the population disperses ≥1 km. Movement distances of D. danis were more than sufficient to locate its host plant, Derris elliptica, which occurred in 61 % of the 20 × 20 m subplots within a 50 ha plot. Compared with temperate species, our three species have much longer life spans, but their movement patterns remain within the known mobility estimates of temperate species. The mobility of D. danis is close to the average for temperate Lycaenidae, while Taenaris sp. is more mobile and P. aspila less mobile than the mean for all temperate species.