Radio telemetry helps record the dispersal patterns of birdwing butterflies in mountainous habitats: Golden Birdwing (Troides aeacus) as an example

Abstract

Birdwing butterflies are a monophyletic group of swallowtail butterflies (Papilionidae) protected by national and international laws and often serve as flagships of insect conservation. Selecting the Golden Birdwing (Troides aeacus) as an example, we demonstrate an effective way to simultaneously record the activity of multiple birdwing butterflies using radio telemetry in hard-to-access mountainous terrain. During the summer flight period of T. aeacus (June and July), a single researcher was able to obtain 30-min records of movement patterns for ten individuals for an average of 4 days by fastening 0.22 g transmitters onto the butterflies, in the mountainous valleys of Mt. Gongga, China. The maximum distance the butterflies traveled over the 4 day period was 4314 m away from the starting location. During this time, the average dispersal rate was 38.07 m/h (n = 9, sd = 85.11); average movement speed was 293.48 m/h (n = 9, sd = 121.45). Flight patterns of butterflies collected from low and high elevation habitats showed no significant differences. Activity levels of individuals from both low and high elevation habitats track diurnal fluctuation in temperature. Flight activity is positively correlated with temperature and negatively correlated with humidity. Our data provide basic parameters of real-time flight activity and dispersal ability for a species of conservation importance. The methodology is highly suitable for monitoring endangered lepidopteran species in otherwise difficult-to-access terrain.