Many animals are marked with conspicuous circular features often called ＇eyespots＇, which intimidate predators, preventing or halting an attack. It has long been assumed that eyespots work by mimicking the eyes of l...Many animals are marked with conspicuous circular features often called ＇eyespots＇, which intimidate predators, preventing or halting an attack. It has long been assumed that eyespots work by mimicking the eyes of larger animals, but recent experiments have indicated that conspicuousness and contrast is important in eyespot function, and not eye mimicry. We undertake two further experiments to distinguish between the conspicuousness and mimicry hypotheses, by using artificial prey presented to wild avian predators in the field. In experiment 1, we test if eyespot effectiveness depends on the marking shape （bar or circle） and arrangement （eye-like and non-eye-like positions）. We find no difference between shapes or arrangement; all spots were equally effective in scaring birds. In experiment 2, we test if the often yellow and black colors of eyespots mimic the eyes of birds of prey. We find no effect of shape, and no advantage to yellow and black spots over non-eye-like but equally conspicuous colors. The consistent finding is that eyespot function lies in being a conspicuous signal to predators, and not necessarily due to eye mimicry [ Current Zoology 55 （5） ： 319 - 326, 2009].展开更多
1 Introduction Sensory ecology deals with how animals capture information from their environment,and the sensory systems involved in doing so(Hailman,1977;Lygoe,1979;Dusenbery, 1992;Mappes and Stevens 2010).Although the
The diversity of anti-predator adaptations in the natural world has long been an active area of research in evolutionary and behavioural biology. A common visually-obvious feature found on prey are ＇eyespots＇, being...The diversity of anti-predator adaptations in the natural world has long been an active area of research in evolutionary and behavioural biology. A common visually-obvious feature found on prey are ＇eyespots＇, being approximately circular mark- ings often with concentric rings and conspicuous colours. These are found on a range of animals, especially adult and larval Lepidoptera and fish. One of the most widespread functions of eyespots seems to be to intimidate or startle predators： delaying, preventing or halting an attack. However, while the fact that they can influence predators in this way is tmcuntroversial, the mechanism（s） behind why they are effective is debated. Traditionally, they have been assumed to work by mimicking the eyes of the predator＇s own enemies, and much research in this field is conducted under the implicit or explicit assumption that this theory is correct. However, eyespots might work simply by being highly salient stimuli that promote sensory overload, biases, or neo- phobic reactions in predators. A range of recent studies has aimed to test these alternatives. Here, we critically evaluate this work and what it tells us about the mechanisms underlying eyespot function. We conclude that although eye mimicry is plausible, there remains a lack of evidence to support it and most observations are at least equally consistent with alternative mechanisms. Finally we also discuss how the debate can be resolved展开更多
1 Introduction The study of anti-predator coloration and behaviour has a long and rich history in biology. It has from the very outset of Darwin＇s theory of natural selection provided numerous areas to test mechanis...1 Introduction The study of anti-predator coloration and behaviour has a long and rich history in biology. It has from the very outset of Darwin＇s theory of natural selection provided numerous areas to test mechanisms and function in evolution. While Darwin perhaps concentrated most of his attention regarding animal coloration on his theory of sexual selection （Darwin, 1871）, his contem- poraries placed much greater emphasis and time to explain the variety of ways that coloration and behaviour protected animals from attack from predators.展开更多
基金supported by a Research Fellowship from Girton College,Cambridge,and a Royal Society Research Grantby an Association for the Study of Animal Behaviour Undergraduate Project Scholarship+1 种基金by a Nuffield Undergraduate Science Bursaryby a Department of Zoology J Arthur Ramsay Trust Fund
文摘Many animals are marked with conspicuous circular features often called ＇eyespots＇, which intimidate predators, preventing or halting an attack. It has long been assumed that eyespots work by mimicking the eyes of larger animals, but recent experiments have indicated that conspicuousness and contrast is important in eyespot function, and not eye mimicry. We undertake two further experiments to distinguish between the conspicuousness and mimicry hypotheses, by using artificial prey presented to wild avian predators in the field. In experiment 1, we test if eyespot effectiveness depends on the marking shape （bar or circle） and arrangement （eye-like and non-eye-like positions）. We find no difference between shapes or arrangement; all spots were equally effective in scaring birds. In experiment 2, we test if the often yellow and black colors of eyespots mimic the eyes of birds of prey. We find no effect of shape, and no advantage to yellow and black spots over non-eye-like but equally conspicuous colors. The consistent finding is that eyespot function lies in being a conspicuous signal to predators, and not necessarily due to eye mimicry [ Current Zoology 55 （5） ： 319 - 326, 2009].
基金supported by a Biotechnology and Biological Sciences Research Council David Phillips Fellowship (BB/G022887/1)
文摘1 Introduction Sensory ecology deals with how animals capture information from their environment,and the sensory systems involved in doing so(Hailman,1977;Lygoe,1979;Dusenbery, 1992;Mappes and Stevens 2010).Although the
文摘The diversity of anti-predator adaptations in the natural world has long been an active area of research in evolutionary and behavioural biology. A common visually-obvious feature found on prey are ＇eyespots＇, being approximately circular mark- ings often with concentric rings and conspicuous colours. These are found on a range of animals, especially adult and larval Lepidoptera and fish. One of the most widespread functions of eyespots seems to be to intimidate or startle predators： delaying, preventing or halting an attack. However, while the fact that they can influence predators in this way is tmcuntroversial, the mechanism（s） behind why they are effective is debated. Traditionally, they have been assumed to work by mimicking the eyes of the predator＇s own enemies, and much research in this field is conducted under the implicit or explicit assumption that this theory is correct. However, eyespots might work simply by being highly salient stimuli that promote sensory overload, biases, or neo- phobic reactions in predators. A range of recent studies has aimed to test these alternatives. Here, we critically evaluate this work and what it tells us about the mechanisms underlying eyespot function. We conclude that although eye mimicry is plausible, there remains a lack of evidence to support it and most observations are at least equally consistent with alternative mechanisms. Finally we also discuss how the debate can be resolved
文摘1 Introduction The study of anti-predator coloration and behaviour has a long and rich history in biology. It has from the very outset of Darwin＇s theory of natural selection provided numerous areas to test mechanisms and function in evolution. While Darwin perhaps concentrated most of his attention regarding animal coloration on his theory of sexual selection （Darwin, 1871）, his contem- poraries placed much greater emphasis and time to explain the variety of ways that coloration and behaviour protected animals from attack from predators.
