Factors affecting equal catchability in two swallowtail butterflies, Papilio polyxenes and P.glaucus

Abstract. 1. Recapture probabilities were analysed for individually marked black swallowtails, Papilio polyxenes F., and tiger swallowtails, P.glaucus L. (Lepidoptera: Papilionidae). 2. Recapture rates differed with sex and behaviour at time of capture for P.polyxenes , but not with age. For P.glaucus , only differences related to behaviour at time of capture were significant. 3. Black swallowtail males that were not physically restrained in identification had a recapture probability (73%) that was significantly higher than the 45% for males that were captured and handled. The higher rate was also exhibited by released, laboratory‐reared males. 4. The capture effect was due to increased dispersal out of the areas and not to avoidance of capture or the capture site.