No abstract

In many animals, males bear bright ornamental color patches that may signal both the 6 direct and indirect benefits that a female might accrue from mating with him. Here we test 7 whether male coloration in the Pipevine Swallowtail butterfly, Battus philenor, predicts two 8 potential direct benefits for females, copulation duration and the quantity of materials the male 9 passes to the female during mating. In this species, males have a bright iridescent blue field on 10 the dorsal hindwing surface while females have little or no dorsal iridescence. Females 11 preferentially mate with males who display a bright and highly chromatic blue on their dorsal 12 hindwing. In this study, we show that the chroma of the blue on the male dorsal hindwing and 13 male body size (forewing length) significantly predict the mass of material or spermatophore that 14 a male forms within the female's copulatory sac during mating. We also found that 15 spermatophore mass correlated negatively with copulation duration, but that color variables did 16 not significantly predict this potential direct benefit. These results suggest that females may 17 enhance the material benefits they receive during mating by mating with males based on the 18 coloration of their dorsal hindwing.