Food selection and reproductive success of Paragymnopleurus sinuatus on three kinds of dung

Dung beetles tunnelers comprise a group of important decomposers in ecosystems. They move animal dung, mainly mammalian excrement, into tunnels for a food supply or for their reproduction. In the Kaohsiung area, three common species of dung beetles are Onthophagus trituber Wiedeman, O. taurinus White, and O. proletarius Harold. The objectives of this study were to investigate the dung preferences of these three species both in the field and laboratory, and to compare their reproductive success when feeding on four kinds of dung. The results indicate that the dung preference of the three Onthophagus species were in the sequence of humans and dogs, monkeys, and cattle. All three species could reproduce successfully using any of these four kinds of dung. Despite there being no significant differences among the size of brood balls, offspring reared with cattle dung had the smallest body size for the same size of brood ball. In conclusion, the three common species of Onthophagus in the Kaohsiung area prefer feeding on dung of omnivorous mammals (humans and dogs) over that of herbivorous mammals (cattle). Both omnivore and herbivore dung can be used by these three Onthophagus species to reproduce successfully, but the body size of offspring tended to be larger when using omnivore dung.