Conspicuous coloration in animals serves many functions such as anti-predation.Anti-predation strategies include motion dazzle and flash behavior.Motion dazzle markings can reduce the probability of being preyed on be...Conspicuous coloration in animals serves many functions such as anti-predation.Anti-predation strategies include motion dazzle and flash behavior.Motion dazzle markings can reduce the probability of being preyed on because the predators misjudge their movement.In flash behavior,prey demonstrate conspicuous cue while fleeing;the predators follow them;however,the prey hide their markings and the predators assume that the prey has vanished.To investigate whether bovids use conspicuous hindquarter markings as an anti-predatory behavior,we undertook phylogenetically controlled analyses to explore under what physiological characteristics and environmental factors bovids might have this color pattern.The results suggested that rump patches and tail markings were more prevalent in bovids living in larger-sized groups,which supports the hypothesis of intraspecific communication.Moreover,we observed the occurrence of conspicuous white hindquarter markings in bovids having smaller body size and living in larger groups,suggesting a motion dazzle function.However,the feature of facultative exposing color patterns(flash markings)was not associated with body size,which was inconsistent with predictions and implied that bovids may not adopt this as an anti-predator strategy.It was concluded that species in bovids with conspicuous white hindquarter markings adopt motion dazzle as an anti-predation strategy while fleeing and escaping from being prey on.展开更多
Exploring the predator prey linkage in food chain system is the most familiar research work in population biology.Recently,some research experiments show that predator-prey interaction not only governed by direct hunt...Exploring the predator prey linkage in food chain system is the most familiar research work in population biology.Recently,some research experiments show that predator-prey interaction not only governed by direct hunting but also influenced by some indirect effect such as fear effect(felt by prey)that may change the physiological behavior of prey.Based upon this fact,we consider a tritrophic food chain model incorporating with anti-predation response(fear effect)and multiple time delays for biomass conversion from prey to middle predator and middle to top predator.We analyze the resulting delay differential equations and explore how the anti-predation response level affects the population dynamics.We also investigate the effect of delay parameters,for which the model system switches its stability through Hopf-bifurcation.We compare all of our results between two different food chain models consisting of two different functional responses.Some numerical simulations are performed to validate the effectiveness of the derived theoretical results.展开更多
Nest predation is the leading cause of reproductive failure in birds and a major driving force in the evolution of anti-predation strategies.Current studies on the anti-predation strategies of birds driven by predatio...Nest predation is the leading cause of reproductive failure in birds and a major driving force in the evolution of anti-predation strategies.Current studies on the anti-predation strategies of birds driven by predation pressure have mainly focused on adults.However,the detection and behavioral responses of nestlings toward predation risk require further investigation.In this study,we examined nestling responses to predator sounds.Two species of nestlings,the Reed Parrotbill(Paradoxornis heudei)and Vinous-throated Parrotbill(Sinosuthora webbiana),were exposed to the Sparrowhawk(Accipiter nisus,less common)and Oriental Magpie(Pica serica,more common),which are predator species,the Oriental Turtle Dove(Streptopelia orientalis),which is a commonly found harmless species,and background noise.Our findings revealed that compared to pre-playback of natural begging and playback of background noise and Oriental Turtle Dove sounds,playback of the two predator types decreased the total begging time and total number of calls of the two nestlings species,with the calls of the Sparrowhawk leading to greater suppression of nestling begging behavior than those of the Oriental Magpie.Therefore,our results indicated that these nestlings were able to distinguish predators from harmless species based on auditory cues.展开更多
Recognition of heterospecific mobbing calls can occur through both innate and learned mechanisms,with the former often explained by two main hypotheses:the acoustic similarity hypothesis,which emphasizes shared acoust...Recognition of heterospecific mobbing calls can occur through both innate and learned mechanisms,with the former often explained by two main hypotheses:the acoustic similarity hypothesis,which emphasizes shared acoustic features,and the phylogenetic conservatism hypothesis,which posits that closely related species may share innate decoding templates.However,it remains unclear whether phylogenetic relatedness alone can drive the recognition of unfamiliar mobbing calls,a question with important implications for understanding the evolution of interspecific communication and anti-predator strategies.We examined the recognition of unfamiliar mobbing calls in Masked Laughingthrushes(Pterorhinus perspicillatus) using playback experiments with three allopatric species' mobbing calls of Leiothrichidae family.Results revealed two key findings:(1) Masked Laughingthrushes exhibited mobbing responses to unfamiliar mobbing calls,though at significantly lower intensity compared to conspecific playbacks.(2) Phylogenetic relatedness significantly predicted mobbing intensity,independent of overall acoustic similarity.These findings improve our understanding of how birds like Masked Laughingthrush instinctively recognize mobbing calls from other species.We show phylogenetic relatedness rather than overall acoustic similarity may be a key to this innate ability.Species that share a common ancestor may possess similar built-in neural systems for decoding alarm signals.We suggest that future research needs to combine neurobiological techniques to determine how inherited biases and feature decoding system together guide variable bird communities to perceive heterospecific mobbing calls.展开更多
Animals must strike a balance between anti-predation behavior and other essential behaviors,such as foraging.Within the same species,strategies may vary on individuals’risk-taking preferences,and in this process the ...Animals must strike a balance between anti-predation behavior and other essential behaviors,such as foraging.Within the same species,strategies may vary on individuals’risk-taking preferences,and in this process the environment is a determinant,in addition to predator regime.The Crested Ibis(Nipponia nippon)exhibits such tendency.This is an endangered species,once inhabiting exclusively in China’s Qinling Mountain.This used to be the sole remaining wild population.However,over recent decades,this population has expanded.A portion has relocated to breed in the lower plain area,which is characterized by elevated level of human activities and landscape complexity.We used flight initiation distance(FID)as an indicator of the ibises’risk-taking preference,particularly their response to human proximity.Additionally,we examined the environmental factors influencing their foraging site selection,including altitude,terrain openness,human activity intensity and human construction.Our findings revealed a significantly shorter FID among individuals relocating to plain habitats,indicating a higher tolerance of human proximity.The results showed that FID decreased with distance to the nearest human settlement.Another finding is that FID was independent of instant human activity intensity and environmental factors(altitude and terrain openness).These different may arise from various combinations of human activity,predation risk,and food abundance within the two habitats.These results provide insights into the in situ conservation of the threatened species within the context of global urbanization.展开更多
Although it is well known that birds can assess predation risk through visual and auditory cues, there has been little research into whether similar processes occur with olfactory cues. We examined the role of odor cu...Although it is well known that birds can assess predation risk through visual and auditory cues, there has been little research into whether similar processes occur with olfactory cues. We examined the role of odor cues in assessing nest predation risk in four species of passerine birds in New Zealand. We compared the ability of two introduced European species （common starling Sturnus vulgaris and song thrush Turdus philomelos） and two native New Zealand species （rifleman Acanthisitta chloris and South Island robin Petroica australis） to respond to the scent of rat urine placed in the nest. Rats are an introduced predator in New Zealand and we expected the native birds, which did not co-evolve with any mammalian predators, to lack behavioral adaptations to the scent of rats at their nest. As expected, both riflemen and robins failed to show any change in their behavior at their nest when rat urine was present compared to a control period in which no scent was present. However, a similar lack of re- sponse was observed in the introduced song thrush; only the common starling changed its behavior in the presence of the rat urine Starlings with rat urine at the nest box were more likely to hesitate before entering and they also approached the nest, but refused to enter more often in the presence of rat scent. Both responses suggest they detected the presence of a predator and changed their behavior to minimize risk to themselves. Although based on a small number of species, our results suggest that responses to pre- dator scent may be less common in New Zealand species, and may be a factor contributing to the vulnerability of native birds to introduced mammalian predators [Current Zoology 61 （1）： 34-41, 2015].展开更多
Camouflage is widespread throughout the animal kingdom allowing individuals to avoid detection and hence save time and energy rather than escape from an approaching predator.Thus,camouflage is likely to have co-evolve...Camouflage is widespread throughout the animal kingdom allowing individuals to avoid detection and hence save time and energy rather than escape from an approaching predator.Thus,camouflage is likely to have co-evolved with antipredator behavior.Here,we propose that camouflage results in dichotomous escape behavior within and among species with classes of individuals and species with cryptic coloration having shorter flight initiation distances(FIDs;the distance at which an individual takes flight when approached by a human).We report the results of 2 tests of this hypothesis.First,bird species with cryptically colored plumage have consistently shorter FID than closely related species without such color.Within species with sexually dimorphic plumage,brightly colored adult male common pheasants Phasianus colchicus and golden pheasants Chrysolophus pictus have long and variable FID,whereas cryptically colored juveniles and adult females have short and invariable FID.Second,FID in females was predicted by presence or absence of cryptic color,FID in males and their interaction.These findings are consistent with the hypothesis that risk-taking behavior has been attuned to camouflage,and that species with different levels of camouflage differ consistently in their FID.展开更多
Correlations among behavioral traits can generate trade-offs and constrain phenotypic evolution. Interspecific hybridization has the potential to alter behavioral trait correlations, but the effect of hybridization on...Correlations among behavioral traits can generate trade-offs and constrain phenotypic evolution. Interspecific hybridization has the potential to alter behavioral trait correlations, but the effect of hybridization on suites of behavioral traits has received relatively little attention. We evaluated how natural hybridization changes the relationship between boldness （time of emergence and proportion of time out of shelter） and response to a simulated predator threat in swordtails （Teleostei： Xiphophorus）. In poeciliid fishes, bold individuals have increased survival in the presence of predators. This non-intuitive observation may arise as a result of bold individuals being more likely to engage in anti-predator behaviors. Contrary to our prediction, bold indi- viduals were less likely to perform a fast-start response to a predator threat. This correlation was consistent among populations and species but was only significant in hybrids. The observed correlation between boldness and anti-predator behavior could im- pact hybrid fitness and the evolvability of hybrid lineages. More generally, our findings suggest that hybridization could influence the integration of behavioral phenotypes, as has been amply documented for morphology. Animal personality and behavioral syndromes could therefore play an important role in the evolutionary fate of natural hybrids [Current Zoology 61 （4）： 596-603, 2015].展开更多
In many butterfly species of the family Lycaenidae, the morphology and color pattern of the hind wings, together with certain behaviors, suggests the presence of a false head （FH） at the posterior end of the perchin...In many butterfly species of the family Lycaenidae, the morphology and color pattern of the hind wings, together with certain behaviors, suggests the presence of a false head （FH） at the posterior end of the perching individual. This FH is consi- dered an adaptation to escape from visually oriented predators. A frequent component of the FH are the tails that presumably resemble the antennae, and the typical hind wings back-and-forth movement along the sagittal plane （HWM） performed while perching apparently move the tails in a way that mimics antennal movement. By exposing 33 individuals from 18 species of Lycaenidae to a stuffed insectivorous bird, we tested two alternative hypotheses regarding HWM. The first hypothesis proposes that, when the butterfly is observed at close range, the HWM distorts the shape of the false head thus reducing its deceiving effect and, therefore, selection will favor butterflies that stop moving their wings when a predator is close by; the second hypothesis says that an increase in the frequency of HWM improves its deflective effect when the butterfly confronts a predator at close range. Our results tend to support the second hypothesis because half of the butterflies started to move their hind wings or increased the rate of HWM when exposed to the stuffed bird; however a substantial proportion of butterflies （30%） stopped moving their hind wings or decreased the rate of HWM as expected from the first hypothesis. Our observations also showed that there is great variation in the rates of HWM, and demonstrated the existence of alternative ways of producing ＂vivid＂ movement of the hind wing tails （the ＂false antennae＂） in the absence of HWM [Current Zoology 61 （4）： 758-764, 2015].展开更多
Assessment of individual costs of the anti-predator defence translating into changes in population parameters is meagre.This is because prey responses are likely to be modulated by additional factors,commonly present ...Assessment of individual costs of the anti-predator defence translating into changes in population parameters is meagre.This is because prey responses are likely to be modulated by additional factors,commonly present in the environment,but often neglected in experimental studies.To evaluate the effect of external factors on prey behavior and physiology,we exposed amphipods Dikerogammarus villosus and Gammarus jazdzewskii to the predation cue of Perca fluviatilis in different densities and light conditions.Singletons of both species exposed to the predation cue in light modified their oxygen consumption(D.villosus:reduction,G.jadzewskii:increase)compared to their respiration in predator-free conditions.However,in the presence of conspecifics or in darkness,their respiration became insensitive to the predation cue.On the other hand,the swimming activity of prey was reduced in the presence of the predation cue irrespective of prey density and light conditions,but singletons were consistently more active than groups.Thus,external factors,such as conspecifics and darkness,constantly or periodically occurring in the field,may reduce the costs of predator non-consumptive effects compared to the costs measured under laboratory conditions(in light or absence of conspecifics).Moreover,we showed that behavioral and physiological parameters of prey may change differently in response to predation risk.Thus,conclusions drawn on the basis of single defence mechanisms and/or results obtained in artificial conditions,not reflecting the environmental complexity,strongly depend on the experimental design and endpoint selection and therefore should be treated with care.展开更多
Abstract Multiple studies have focused on the importance of single modalities （visual, auditory, olfactory） in eliciting anti-predator behavior, however multiple channels are often engaged simultaneously. While exam...Abstract Multiple studies have focused on the importance of single modalities （visual, auditory, olfactory） in eliciting anti-predator behavior, however multiple channels are often engaged simultaneously. While examining responses to multiple cues can potentially reveal more complex behavioral responses, little is known about how multimodal processing evolves. By contrasting response to familiar and novel predators, insights can be gained into the evolution of multimodal responses. We studied brown anoles＇ （Anolis sagrei） response to acoustic and visual predatory cues of a common potential predator, the great-tailed grackle Quiscalus mexicanus and to the American kestrel Falco sparverius, a species found in other populations but not present in our study population. We observed anole behavior before and after a stimulus and quantified rates of looking, display, and locomotion. Anoles increased their rate of locomotion in response to grackle models, an effect modulated by grackle vocalizations. No such response or modulation was seen when anoles were presented with kestrel stimuli. This suggests that the degree of sophistication of anole response to predators is experience dependent and that relaxed selection can result in reduced anti-predator response following loss of predators.展开更多
Anti-predation strategies are critical to animal survival and are fundamental to deciphering predator–prey interactions.As an important defense strategy,sensory predator detection(such as through acoustic and visual ...Anti-predation strategies are critical to animal survival and are fundamental to deciphering predator–prey interactions.As an important defense strategy,sensory predator detection(such as through acoustic and visual cues)enables animals to assess predation risk and execute predator-avoidance behavior;however,there are limited studies on the anti-predation behavior of nocturnal animals.The prey of bats provides an excellent representative system for examining the anti-predation behavior of nocturnal animals.Here,we broadcasted different types of echolocation calls of the bird-eating bat Ia io to two wild passerine birds,namely,Zosterops japonicus and Sinosuthora webbiana,that are preyed upon by I.io,and presented the birds with individual bats under different light intensities.The results showed that both bird species were able to perceive the low-frequency audible portion of the bats’echolocation calls;however,they did not exhibit escape responses to the acoustic stimuli.In the dark and under moonlit conditions,both bird species were unable to respond to active bats at close range and the birds only exhibited evasive flight behavior when bats approached or touched them.These results suggest that nocturnal passerine birds may not be able to use acoustic or visual cues to detect bats and adopt evasive maneuvers to avoid predation.This work suggests that bat predation pressure may not elicit primary predator-avoidance responses in nocturnal passerine birds.The results provide new insights into the anti-predation behavior of nocturnal animals.展开更多
基金This study received support from the Tibet Major Science and Technology Project(XZ201901-GA-06).
文摘Conspicuous coloration in animals serves many functions such as anti-predation.Anti-predation strategies include motion dazzle and flash behavior.Motion dazzle markings can reduce the probability of being preyed on because the predators misjudge their movement.In flash behavior,prey demonstrate conspicuous cue while fleeing;the predators follow them;however,the prey hide their markings and the predators assume that the prey has vanished.To investigate whether bovids use conspicuous hindquarter markings as an anti-predatory behavior,we undertook phylogenetically controlled analyses to explore under what physiological characteristics and environmental factors bovids might have this color pattern.The results suggested that rump patches and tail markings were more prevalent in bovids living in larger-sized groups,which supports the hypothesis of intraspecific communication.Moreover,we observed the occurrence of conspicuous white hindquarter markings in bovids having smaller body size and living in larger groups,suggesting a motion dazzle function.However,the feature of facultative exposing color patterns(flash markings)was not associated with body size,which was inconsistent with predictions and implied that bovids may not adopt this as an anti-predator strategy.It was concluded that species in bovids with conspicuous white hindquarter markings adopt motion dazzle as an anti-predation strategy while fleeing and escaping from being prey on.
文摘Exploring the predator prey linkage in food chain system is the most familiar research work in population biology.Recently,some research experiments show that predator-prey interaction not only governed by direct hunting but also influenced by some indirect effect such as fear effect(felt by prey)that may change the physiological behavior of prey.Based upon this fact,we consider a tritrophic food chain model incorporating with anti-predation response(fear effect)and multiple time delays for biomass conversion from prey to middle predator and middle to top predator.We analyze the resulting delay differential equations and explore how the anti-predation response level affects the population dynamics.We also investigate the effect of delay parameters,for which the model system switches its stability through Hopf-bifurcation.We compare all of our results between two different food chain models consisting of two different functional responses.Some numerical simulations are performed to validate the effectiveness of the derived theoretical results.
基金funded by the National Natural Science Foundation of China (32301295 to J.W.,32101242 to L.M.and 32260253 to L.W.)High-Level Talents Research Start-Up Project of Hebei University (521100222044 to J.W.)。
文摘Nest predation is the leading cause of reproductive failure in birds and a major driving force in the evolution of anti-predation strategies.Current studies on the anti-predation strategies of birds driven by predation pressure have mainly focused on adults.However,the detection and behavioral responses of nestlings toward predation risk require further investigation.In this study,we examined nestling responses to predator sounds.Two species of nestlings,the Reed Parrotbill(Paradoxornis heudei)and Vinous-throated Parrotbill(Sinosuthora webbiana),were exposed to the Sparrowhawk(Accipiter nisus,less common)and Oriental Magpie(Pica serica,more common),which are predator species,the Oriental Turtle Dove(Streptopelia orientalis),which is a commonly found harmless species,and background noise.Our findings revealed that compared to pre-playback of natural begging and playback of background noise and Oriental Turtle Dove sounds,playback of the two predator types decreased the total begging time and total number of calls of the two nestlings species,with the calls of the Sparrowhawk leading to greater suppression of nestling begging behavior than those of the Oriental Magpie.Therefore,our results indicated that these nestlings were able to distinguish predators from harmless species based on auditory cues.
文摘Recognition of heterospecific mobbing calls can occur through both innate and learned mechanisms,with the former often explained by two main hypotheses:the acoustic similarity hypothesis,which emphasizes shared acoustic features,and the phylogenetic conservatism hypothesis,which posits that closely related species may share innate decoding templates.However,it remains unclear whether phylogenetic relatedness alone can drive the recognition of unfamiliar mobbing calls,a question with important implications for understanding the evolution of interspecific communication and anti-predator strategies.We examined the recognition of unfamiliar mobbing calls in Masked Laughingthrushes(Pterorhinus perspicillatus) using playback experiments with three allopatric species' mobbing calls of Leiothrichidae family.Results revealed two key findings:(1) Masked Laughingthrushes exhibited mobbing responses to unfamiliar mobbing calls,though at significantly lower intensity compared to conspecific playbacks.(2) Phylogenetic relatedness significantly predicted mobbing intensity,independent of overall acoustic similarity.These findings improve our understanding of how birds like Masked Laughingthrush instinctively recognize mobbing calls from other species.We show phylogenetic relatedness rather than overall acoustic similarity may be a key to this innate ability.Species that share a common ancestor may possess similar built-in neural systems for decoding alarm signals.We suggest that future research needs to combine neurobiological techniques to determine how inherited biases and feature decoding system together guide variable bird communities to perceive heterospecific mobbing calls.
基金supported by National Natural Science Foundation of China(No.32270554 to CD)。
文摘Animals must strike a balance between anti-predation behavior and other essential behaviors,such as foraging.Within the same species,strategies may vary on individuals’risk-taking preferences,and in this process the environment is a determinant,in addition to predator regime.The Crested Ibis(Nipponia nippon)exhibits such tendency.This is an endangered species,once inhabiting exclusively in China’s Qinling Mountain.This used to be the sole remaining wild population.However,over recent decades,this population has expanded.A portion has relocated to breed in the lower plain area,which is characterized by elevated level of human activities and landscape complexity.We used flight initiation distance(FID)as an indicator of the ibises’risk-taking preference,particularly their response to human proximity.Additionally,we examined the environmental factors influencing their foraging site selection,including altitude,terrain openness,human activity intensity and human construction.Our findings revealed a significantly shorter FID among individuals relocating to plain habitats,indicating a higher tolerance of human proximity.The results showed that FID decreased with distance to the nearest human settlement.Another finding is that FID was independent of instant human activity intensity and environmental factors(altitude and terrain openness).These different may arise from various combinations of human activity,predation risk,and food abundance within the two habitats.These results provide insights into the in situ conservation of the threatened species within the context of global urbanization.
文摘Although it is well known that birds can assess predation risk through visual and auditory cues, there has been little research into whether similar processes occur with olfactory cues. We examined the role of odor cues in assessing nest predation risk in four species of passerine birds in New Zealand. We compared the ability of two introduced European species （common starling Sturnus vulgaris and song thrush Turdus philomelos） and two native New Zealand species （rifleman Acanthisitta chloris and South Island robin Petroica australis） to respond to the scent of rat urine placed in the nest. Rats are an introduced predator in New Zealand and we expected the native birds, which did not co-evolve with any mammalian predators, to lack behavioral adaptations to the scent of rats at their nest. As expected, both riflemen and robins failed to show any change in their behavior at their nest when rat urine was present compared to a control period in which no scent was present. However, a similar lack of re- sponse was observed in the introduced song thrush; only the common starling changed its behavior in the presence of the rat urine Starlings with rat urine at the nest box were more likely to hesitate before entering and they also approached the nest, but refused to enter more often in the presence of rat scent. Both responses suggest they detected the presence of a predator and changed their behavior to minimize risk to themselves. Although based on a small number of species, our results suggest that responses to pre- dator scent may be less common in New Zealand species, and may be a factor contributing to the vulnerability of native birds to introduced mammalian predators [Current Zoology 61 （1）： 34-41, 2015].
基金National Natural Science Foundation of China(Nos 30860044,31472013,and 31772453).D.S.M.S was supported by Coordenaqao de Aperfeiqoamento de Pessoal de Ensino Superior.
文摘Camouflage is widespread throughout the animal kingdom allowing individuals to avoid detection and hence save time and energy rather than escape from an approaching predator.Thus,camouflage is likely to have co-evolved with antipredator behavior.Here,we propose that camouflage results in dichotomous escape behavior within and among species with classes of individuals and species with cryptic coloration having shorter flight initiation distances(FIDs;the distance at which an individual takes flight when approached by a human).We report the results of 2 tests of this hypothesis.First,bird species with cryptically colored plumage have consistently shorter FID than closely related species without such color.Within species with sexually dimorphic plumage,brightly colored adult male common pheasants Phasianus colchicus and golden pheasants Chrysolophus pictus have long and variable FID,whereas cryptically colored juveniles and adult females have short and invariable FID.Second,FID in females was predicted by presence or absence of cryptic color,FID in males and their interaction.These findings are consistent with the hypothesis that risk-taking behavior has been attuned to camouflage,and that species with different levels of camouflage differ consistently in their FID.
基金We would like to thank the Mexican federal government and the state of Hidalgo for providing permits to collect fish and Nick Ratterman, Kirk Winemiller and Lee Fitzgerald for helpful comments on early versions of this manuscript. This work was supported by funding provided by a National Science Foundation grant （I0S-0923825） award- ed to G.G.R.R.E. was supported by an Undergraduate Program in Biological and Mathematical Sciences （UBM National Science Foundation grant （DBI-1029401） directed by Dr. Jay Walton. All experiments conducted in this study complied with current state, federal, and local laws in the United States and Mexico.
文摘Correlations among behavioral traits can generate trade-offs and constrain phenotypic evolution. Interspecific hybridization has the potential to alter behavioral trait correlations, but the effect of hybridization on suites of behavioral traits has received relatively little attention. We evaluated how natural hybridization changes the relationship between boldness （time of emergence and proportion of time out of shelter） and response to a simulated predator threat in swordtails （Teleostei： Xiphophorus）. In poeciliid fishes, bold individuals have increased survival in the presence of predators. This non-intuitive observation may arise as a result of bold individuals being more likely to engage in anti-predator behaviors. Contrary to our prediction, bold indi- viduals were less likely to perform a fast-start response to a predator threat. This correlation was consistent among populations and species but was only significant in hybrids. The observed correlation between boldness and anti-predator behavior could im- pact hybrid fitness and the evolvability of hybrid lineages. More generally, our findings suggest that hybridization could influence the integration of behavioral phenotypes, as has been amply documented for morphology. Animal personality and behavioral syndromes could therefore play an important role in the evolutionary fate of natural hybrids [Current Zoology 61 （4）： 596-603, 2015].
文摘In many butterfly species of the family Lycaenidae, the morphology and color pattern of the hind wings, together with certain behaviors, suggests the presence of a false head （FH） at the posterior end of the perching individual. This FH is consi- dered an adaptation to escape from visually oriented predators. A frequent component of the FH are the tails that presumably resemble the antennae, and the typical hind wings back-and-forth movement along the sagittal plane （HWM） performed while perching apparently move the tails in a way that mimics antennal movement. By exposing 33 individuals from 18 species of Lycaenidae to a stuffed insectivorous bird, we tested two alternative hypotheses regarding HWM. The first hypothesis proposes that, when the butterfly is observed at close range, the HWM distorts the shape of the false head thus reducing its deceiving effect and, therefore, selection will favor butterflies that stop moving their wings when a predator is close by; the second hypothesis says that an increase in the frequency of HWM improves its deflective effect when the butterfly confronts a predator at close range. Our results tend to support the second hypothesis because half of the butterflies started to move their hind wings or increased the rate of HWM when exposed to the stuffed bird; however a substantial proportion of butterflies （30%） stopped moving their hind wings or decreased the rate of HWM as expected from the first hypothesis. Our observations also showed that there is great variation in the rates of HWM, and demonstrated the existence of alternative ways of producing ＂vivid＂ movement of the hind wing tails （the ＂false antennae＂） in the absence of HWM [Current Zoology 61 （4）： 758-764, 2015].
基金Our study was supported by the grants of the National Science Centre,Poland No.2016/21/B/NZ8/00418 and 2020/39/D/NZ8/01226.
文摘Assessment of individual costs of the anti-predator defence translating into changes in population parameters is meagre.This is because prey responses are likely to be modulated by additional factors,commonly present in the environment,but often neglected in experimental studies.To evaluate the effect of external factors on prey behavior and physiology,we exposed amphipods Dikerogammarus villosus and Gammarus jazdzewskii to the predation cue of Perca fluviatilis in different densities and light conditions.Singletons of both species exposed to the predation cue in light modified their oxygen consumption(D.villosus:reduction,G.jadzewskii:increase)compared to their respiration in predator-free conditions.However,in the presence of conspecifics or in darkness,their respiration became insensitive to the predation cue.On the other hand,the swimming activity of prey was reduced in the presence of the predation cue irrespective of prey density and light conditions,but singletons were consistently more active than groups.Thus,external factors,such as conspecifics and darkness,constantly or periodically occurring in the field,may reduce the costs of predator non-consumptive effects compared to the costs measured under laboratory conditions(in light or absence of conspecifics).Moreover,we showed that behavioral and physiological parameters of prey may change differently in response to predation risk.Thus,conclusions drawn on the basis of single defence mechanisms and/or results obtained in artificial conditions,not reflecting the environmental complexity,strongly depend on the experimental design and endpoint selection and therefore should be treated with care.
文摘Abstract Multiple studies have focused on the importance of single modalities （visual, auditory, olfactory） in eliciting anti-predator behavior, however multiple channels are often engaged simultaneously. While examining responses to multiple cues can potentially reveal more complex behavioral responses, little is known about how multimodal processing evolves. By contrasting response to familiar and novel predators, insights can be gained into the evolution of multimodal responses. We studied brown anoles＇ （Anolis sagrei） response to acoustic and visual predatory cues of a common potential predator, the great-tailed grackle Quiscalus mexicanus and to the American kestrel Falco sparverius, a species found in other populations but not present in our study population. We observed anole behavior before and after a stimulus and quantified rates of looking, display, and locomotion. Anoles increased their rate of locomotion in response to grackle models, an effect modulated by grackle vocalizations. No such response or modulation was seen when anoles were presented with kestrel stimuli. This suggests that the degree of sophistication of anole response to predators is experience dependent and that relaxed selection can result in reduced anti-predator response following loss of predators.
基金supported by the National Natural Science Foundation of China(Grant No.31922050)the Fund of the Jilin Province Science and Technology Development Project(Grant No.20220101273JC)+1 种基金the Fundamental Research Funds for the Central Universities(Grant Nos.2412023QD026 and 2412023YQ002)the Special Foundation for National Science and Technology Basic Research Program of China(Grant No.2021FY100301).
文摘Anti-predation strategies are critical to animal survival and are fundamental to deciphering predator–prey interactions.As an important defense strategy,sensory predator detection(such as through acoustic and visual cues)enables animals to assess predation risk and execute predator-avoidance behavior;however,there are limited studies on the anti-predation behavior of nocturnal animals.The prey of bats provides an excellent representative system for examining the anti-predation behavior of nocturnal animals.Here,we broadcasted different types of echolocation calls of the bird-eating bat Ia io to two wild passerine birds,namely,Zosterops japonicus and Sinosuthora webbiana,that are preyed upon by I.io,and presented the birds with individual bats under different light intensities.The results showed that both bird species were able to perceive the low-frequency audible portion of the bats’echolocation calls;however,they did not exhibit escape responses to the acoustic stimuli.In the dark and under moonlit conditions,both bird species were unable to respond to active bats at close range and the birds only exhibited evasive flight behavior when bats approached or touched them.These results suggest that nocturnal passerine birds may not be able to use acoustic or visual cues to detect bats and adopt evasive maneuvers to avoid predation.This work suggests that bat predation pressure may not elicit primary predator-avoidance responses in nocturnal passerine birds.The results provide new insights into the anti-predation behavior of nocturnal animals.
