Populations of the spot-legged treefrogs(Polypedates megacephalus) in China show significant morphological variation,but no has yet been conducted to investigate the correlation between morphological variation and gen...Populations of the spot-legged treefrogs(Polypedates megacephalus) in China show significant morphological variation,but no has yet been conducted to investigate the correlation between morphological variation and genetic/ecological divergence.In this study,mitochondrial DNA sequences from the 12S rRNA gene(374 bp) were amplified from 25 individual spot-legged treefrogs from southern Yunnan,China.The phylogenetic analysis using Bayesian Inference determined two haplotype clades,different from those detected by Richards and Moore(1998).Our results suggest that the phylogenetic lineages reconstructed in this study are not correlated with morphology,thus indicating that the populations in southern Yunnan may be P.leucomystax rather than P.megacephalus.展开更多
Disentangling the influence of multiple signal components on receivers and elucidating general processes influencing complex signal evolution are difficult tasks. In this study we test mate preferences of female squir...Disentangling the influence of multiple signal components on receivers and elucidating general processes influencing complex signal evolution are difficult tasks. In this study we test mate preferences of female squirrel treefrogs Hyla squirella and female tungara frogs Physalaemus pustulosus for similar combinations of acoustic and visual components of their multimodal courtship signals. In a two-choice playback experiment with squirrel treefrogs, the visual stimulus of a male model significantly increased the attractivness of a relatively unattractive slow call rate. A previous study demonstrated that faster call rates are more attractive to female squirrel treefrogs, and all else being equal, models of male frogs with large body stripes are more attractive. In a similar experiment with female tungara frogs, the visual stimulus of a robotic frog failed to increase the attractiveness of a relatively unattractive call. Females also showed no preference for the distinct stripe on the robot that males commonly bear on their throat. Thus, features of conspicuous signal components such as body stripes are not universally important and signal function is likely to differ even among species with similar ecologies and communication systems. Finally, we discuss the putative information content of anuran signals and suggest that the categorization of redundant versus multiple messages may not be sufficient as a general explanation for the evolution of multimodal signaling. Instead of relying on untested assumptions concerning the information content of signals, we discuss the value of initially collecting comparative empirical data sets related to receiver responses.展开更多
Niche differentiation enables ecologically similar species to coexist by lessening competition over food and/or shelters and may be critical for reproductive isolation between closely related species in close proximit...Niche differentiation enables ecologically similar species to coexist by lessening competition over food and/or shelters and may be critical for reproductive isolation between closely related species in close proximity.Because no extra traits need to evolve,spatial and temporal differentiation may readily take place to complement other isolating mechanisms.Two closely related treefrog species occur together in Korea:the endangered Hyla suweonensis and the widespread Hyla japonica.Advertisement calls are differentiated,but it is unclear whether call difference is sufficient for reproductive isolation.We tracked individuals of both species to study fine-scale differentiation in microhabitat use in the diel cycle of the breeding season using a harmonic direction finder.tracking male movement patterns of both species revealed spatial and temporal differentiation in microhabitat use for calling and resting during the breeding season.Males of both H.suweonensis and H.japonica occurred in all 5 microhabitats identified in this study:rice paddy,ground,buried,grass and bush.Both treefrog species showed general similarities in calling from rice paddies and resting in grass and bush.However,H.suweonensis moved into rice paddies and produced advertisement calls 3 h earlier than H.japonica.These differences likely minimize contact between the species and provide an additional isolating mechanism.In addition,the activity of H.suweonensis may be contributing to the decline of this species,as resting in grass would increase dangers from predatory birds and habitat disturbance.展开更多
基金funded by the National Natural Science Foundation of China(NSF30870281)
文摘Populations of the spot-legged treefrogs(Polypedates megacephalus) in China show significant morphological variation,but no has yet been conducted to investigate the correlation between morphological variation and genetic/ecological divergence.In this study,mitochondrial DNA sequences from the 12S rRNA gene(374 bp) were amplified from 25 individual spot-legged treefrogs from southern Yunnan,China.The phylogenetic analysis using Bayesian Inference determined two haplotype clades,different from those detected by Richards and Moore(1998).Our results suggest that the phylogenetic lineages reconstructed in this study are not correlated with morphology,thus indicating that the populations in southern Yunnan may be P.leucomystax rather than P.megacephalus.
文摘Disentangling the influence of multiple signal components on receivers and elucidating general processes influencing complex signal evolution are difficult tasks. In this study we test mate preferences of female squirrel treefrogs Hyla squirella and female tungara frogs Physalaemus pustulosus for similar combinations of acoustic and visual components of their multimodal courtship signals. In a two-choice playback experiment with squirrel treefrogs, the visual stimulus of a male model significantly increased the attractivness of a relatively unattractive slow call rate. A previous study demonstrated that faster call rates are more attractive to female squirrel treefrogs, and all else being equal, models of male frogs with large body stripes are more attractive. In a similar experiment with female tungara frogs, the visual stimulus of a robotic frog failed to increase the attractiveness of a relatively unattractive call. Females also showed no preference for the distinct stripe on the robot that males commonly bear on their throat. Thus, features of conspicuous signal components such as body stripes are not universally important and signal function is likely to differ even among species with similar ecologies and communication systems. Finally, we discuss the putative information content of anuran signals and suggest that the categorization of redundant versus multiple messages may not be sufficient as a general explanation for the evolution of multimodal signaling. Instead of relying on untested assumptions concerning the information content of signals, we discuss the value of initially collecting comparative empirical data sets related to receiver responses.
基金supported financially by the National Research Foundation of Korea(grant number 2012R1A2A2A01046977).
文摘Niche differentiation enables ecologically similar species to coexist by lessening competition over food and/or shelters and may be critical for reproductive isolation between closely related species in close proximity.Because no extra traits need to evolve,spatial and temporal differentiation may readily take place to complement other isolating mechanisms.Two closely related treefrog species occur together in Korea:the endangered Hyla suweonensis and the widespread Hyla japonica.Advertisement calls are differentiated,but it is unclear whether call difference is sufficient for reproductive isolation.We tracked individuals of both species to study fine-scale differentiation in microhabitat use in the diel cycle of the breeding season using a harmonic direction finder.tracking male movement patterns of both species revealed spatial and temporal differentiation in microhabitat use for calling and resting during the breeding season.Males of both H.suweonensis and H.japonica occurred in all 5 microhabitats identified in this study:rice paddy,ground,buried,grass and bush.Both treefrog species showed general similarities in calling from rice paddies and resting in grass and bush.However,H.suweonensis moved into rice paddies and produced advertisement calls 3 h earlier than H.japonica.These differences likely minimize contact between the species and provide an additional isolating mechanism.In addition,the activity of H.suweonensis may be contributing to the decline of this species,as resting in grass would increase dangers from predatory birds and habitat disturbance.
