Sexual selection in cane toads Rhinella marina： A male＇s body size affects his success and his tactics  

作　　者：Haley BOWCOCK Gregory P. BROWN Richard SHINE 

机构地区：[1]School of Biological Sciences A08, University of Sydney, NSW 2006, Australia

出　　处：《Current Zoology》2013年第6期747-753,共7页动物学报（英文版）

摘　　要：Abstract Male body size can play an important role in the mating systems of anuran amphibians. We conducted labora- tory-based trials with cane toads Rhinella （Bufo） marina from an invasive population in the wet-dry tropics of northern Australia, to clarify the effects of a male＇s body size on his reproductive success and behavior （mate choice）. Males were stimulated with a synthetic hormone to induce reproductive readiness. Larger body size enhanced a male toad＇s ability to displace a smaller rival from amplexus, apparently because of physical strength： more force was required to dislodge a larger than a smaller amplectant male. A male＇s body size also affected his mate-choice criteria. Males of all body sizes were as likely to attempt amplexus with another male as with a female of the same size, and preferred larger rather than smaller sexual targets. However, this size prefe- rence was stronger in larger males and hence, amplexus was size-assortative. This pattern broke down when males were given access to already-amplectant male-female pairs： males of all body sizes readily attempted amplexus with the pair, with no size discrimination. An amplectant pair provides a larger visual stimulus, and prolonged amplexus provides a strong cue for sex iden- tification （one of the individuals involved is almost certainly a female）. Thus, a male cane toad＇s body size affects both his ability to defeat rivals in physical struggles over females, and the criteria he uses when selecting potential mates, but the impacts of that selectivity depend upon the context in which mating occurs

关 键 词：Mating systems Size-assortative mating Large-male advantage ANURANS Invasive species 

分 类 号：S865.9[农业科学—野生动物驯养] U469[农业科学—畜牧兽医]