Choice of Oviposition Site by Hyla Chrysoscelis: Role of Predators and Competitors
1989
Resetarits, William J., Jr | Wilbur, Henry M.
The role of predators and competitors in the choice of oviposition site by the treefrog Hyla chrysoscelis was examined in a randomized complete block experiment using 90 replicated experimental ponds. Control ponds containing neither predators nor competitors were contrasted with treatment ponds into which one of four species of predators (Ambystoma maculatum larvae, Enneacanthus chaetodon adults, Notophthalmus viridescens adults, Tramea carolina larvae) or one of two species of competitors (Rana catesbeiana, Hyla chrysoscelis) was added. Treatments had significant effects on the mean number of eggs deposited in ponds. Fewer eggs were laid in ponds with Ambystoma, Enneacanthus, or Hyla, as a result of fewer females laying eggs and fewer eggs laid per visit, compared with control ponds. Notophthalmus, Rana, and Tramea had no effect on the number of eggs laid. Ovipositing Hyla discriminated among potential oviposition sites based on the species present. Choice of oviposition site can determine the success of a female's reproductive investment, and it can be a mechanism affecting the structure of ecological communities as well. Our results emphasize the importance of oviposition site choice in the evolution of reproductive patterns and implicate species avoidance by ovipositing females as a mechanism important in generating variability in ecological communities.
显示更多 [+] 显示较少 [-]