Information about competition between carnivore species for food within high altitude regions is limited.Data collected from the Taxkorgan Nature Reserve,China revealed important interactions between snow leopard(Pant...Information about competition between carnivore species for food within high altitude regions is limited.Data collected from the Taxkorgan Nature Reserve,China revealed important interactions between snow leopard(Panthera uncia),grey wolf(Canis lupus),red fox(Vulpes vulpes)and their prey species,including domestic livestock.Sixty-four line transects were conducted in order to identify field signs of habitat occupancy and collect scats for diet analysis.High dietary overlap was observed between all three carnivore species:snow leopard and red fox(Pianka’s index=0.96),red fox and grey wolf(Pianka’s index=0.90),snow leopard and grey wolf(Pianka’s index=0.87).Snow leopard and grey wolf showed significant predation on livestock(36.8%for snow leopard and 29.4%for grey wolf in diet composition).As a pioneering exploration of the endangered snow leopard and its relationship with other species within the alpine ecosystem under livestock grazing pressure,this study contributes a greater understanding of the relationship within carnivore guild in the Pamirs whilst providing implications for conservation planning and project implementation activities in China.展开更多
Microorganisms live in almost every habitat on the earth from the poles to the equator,from forest to desert,from mountain to deep sea,from geysers to karst structures,as well as the body of almost all multicellular o...Microorganisms live in almost every habitat on the earth from the poles to the equator,from forest to desert,from mountain to deep sea,from geysers to karst structures,as well as the body of almost all multicellular organisms from plants to animals.Essentially,species among the microbial populations interact in different ways,as predators and prey,or as symbionts in the form of communities.展开更多
The importance of predation risk as a key driver of evolutionary change is exemplified by the Northern Range in Trinidad, where research on guppies living in multiple parallel streams has pro- vided invaluable insight...The importance of predation risk as a key driver of evolutionary change is exemplified by the Northern Range in Trinidad, where research on guppies living in multiple parallel streams has pro- vided invaluable insights into the process of evolution by natural selection. Although Trinidadian guppies are now a textbook example of evolution in action, studies have generally categorized predation as a dichotomous variable, representing high or low risk. Yet, ecologists appreciate that community structure and the attendant predation risk vary substantially over space and time. Here, we use data from a longitudinal study of fish assemblages at 16 different sites in the Northern Range to quantify temporal and spatial variation in predation risk. Specifically we ask： 1） Is there evidence for a gradient in predation risk？ 2） Does the ranking of sites （by risk） change with the defi- nition of the predator community （in terms of species composition and abundance currency）, and 3） Are site rankings consistent over time？ We find compelling evidence that sites lie along a contin- uum of risk. However, site rankings along this gradient depend on how predation is quantified in terms of the species considered to be predators and the abundance currency is used. Nonetheless, for a given categorization and currency, rankings are relatively consistent over time. Our study sug- gests that consideration of predation gradients will lead to a more nuanced understanding of the role of predation risk in behavioral and evolutionary ecology. It also emphasizes the need to justify and report the definition of predation risk being used.展开更多
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
Anomalocaridids were large predators of the Cambrian seas at the top of the trophic pyramid.Complete anomalocaridid specimens have been rarely discovered and the rigid isolated frontal appendages and mouthparts are mo...Anomalocaridids were large predators of the Cambrian seas at the top of the trophic pyramid.Complete anomalocaridid specimens have been rarely discovered and the rigid isolated frontal appendages and mouthparts are more commonly preserved.Here we study new material of the frontal appendages from the Wulongqing Formation,Cambrian Stage 4,Series 2 near Kunming,eastern Yunnan.Two new forms of anomalocaridid frontal appendages are described,namely Anomalocaris kunmingensis sp.nov.and Paranomalocaris multisegmentalis gen.nov.,sp.nov.The frontal appendage of A.kunmingensis sp.nov.probably comprises15 podomeres of which the first one has a weakened skeletoned,the second one is armed with small spines,and the third one is armed with remarkably robust proximal ventral spines with 6 anisomerous auxiliary spines;paired auxiliary spines are associated with podomeres 4–14;podomeres 12–14 are armed with paired dorsal spines,and the last podomere bears 2 distal spines,one spine distinctly larger than the other.The frontal appendage of P.multisegmentalis tapered backwards,consisting of 22 visible podomeres;the most ventral spine is armed with 5 pairs of auxiliary spines,and podomeres 12–21 bear dorsal spines,the last podomere with 2 small distal spines.The new material provides additional evidence for our understanding of the diversity of anomalocaridids in the Cambrian.The morphology of these new finds may indicate the importance of different feeding strategies of anomalocaridids in the Cambrian ecosystem.展开更多
基金supported by the State Forestry Administration of China (SFA)Snow Leopard Network, the Snow Leopard Trust, Panthera+1 种基金Beijing Forestry University and the University of Oxfordthe great support from the Forestry Department of Xinjiang Uygur Autonomous Region, Wildlife Conservation Division of Kashi Region, Taxkorgan Nagure Reserve Administration, Livestock Husbandry Bureau of Taxkorgan County, and government of Mariang community
文摘Information about competition between carnivore species for food within high altitude regions is limited.Data collected from the Taxkorgan Nature Reserve,China revealed important interactions between snow leopard(Panthera uncia),grey wolf(Canis lupus),red fox(Vulpes vulpes)and their prey species,including domestic livestock.Sixty-four line transects were conducted in order to identify field signs of habitat occupancy and collect scats for diet analysis.High dietary overlap was observed between all three carnivore species:snow leopard and red fox(Pianka’s index=0.96),red fox and grey wolf(Pianka’s index=0.90),snow leopard and grey wolf(Pianka’s index=0.87).Snow leopard and grey wolf showed significant predation on livestock(36.8%for snow leopard and 29.4%for grey wolf in diet composition).As a pioneering exploration of the endangered snow leopard and its relationship with other species within the alpine ecosystem under livestock grazing pressure,this study contributes a greater understanding of the relationship within carnivore guild in the Pamirs whilst providing implications for conservation planning and project implementation activities in China.
文摘Microorganisms live in almost every habitat on the earth from the poles to the equator,from forest to desert,from mountain to deep sea,from geysers to karst structures,as well as the body of almost all multicellular organisms from plants to animals.Essentially,species among the microbial populations interact in different ways,as predators and prey,or as symbionts in the form of communities.
文摘The importance of predation risk as a key driver of evolutionary change is exemplified by the Northern Range in Trinidad, where research on guppies living in multiple parallel streams has pro- vided invaluable insights into the process of evolution by natural selection. Although Trinidadian guppies are now a textbook example of evolution in action, studies have generally categorized predation as a dichotomous variable, representing high or low risk. Yet, ecologists appreciate that community structure and the attendant predation risk vary substantially over space and time. Here, we use data from a longitudinal study of fish assemblages at 16 different sites in the Northern Range to quantify temporal and spatial variation in predation risk. Specifically we ask： 1） Is there evidence for a gradient in predation risk？ 2） Does the ranking of sites （by risk） change with the defi- nition of the predator community （in terms of species composition and abundance currency）, and 3） Are site rankings consistent over time？ We find compelling evidence that sites lie along a contin- uum of risk. However, site rankings along this gradient depend on how predation is quantified in terms of the species considered to be predators and the abundance currency is used. Nonetheless, for a given categorization and currency, rankings are relatively consistent over time. Our study sug- gests that consideration of predation gradients will lead to a more nuanced understanding of the role of predation risk in behavioral and evolutionary ecology. It also emphasizes the need to justify and report the definition of predation risk being used.
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
基金supported by the Chinese Academy of Sciences (KZZD-EW-02)the National Basic Research Program of China (2013CB835000)the National Natural Science Foundation of China (41222013, 40872010, 400772020 and J1210006)
文摘Anomalocaridids were large predators of the Cambrian seas at the top of the trophic pyramid.Complete anomalocaridid specimens have been rarely discovered and the rigid isolated frontal appendages and mouthparts are more commonly preserved.Here we study new material of the frontal appendages from the Wulongqing Formation,Cambrian Stage 4,Series 2 near Kunming,eastern Yunnan.Two new forms of anomalocaridid frontal appendages are described,namely Anomalocaris kunmingensis sp.nov.and Paranomalocaris multisegmentalis gen.nov.,sp.nov.The frontal appendage of A.kunmingensis sp.nov.probably comprises15 podomeres of which the first one has a weakened skeletoned,the second one is armed with small spines,and the third one is armed with remarkably robust proximal ventral spines with 6 anisomerous auxiliary spines;paired auxiliary spines are associated with podomeres 4–14;podomeres 12–14 are armed with paired dorsal spines,and the last podomere bears 2 distal spines,one spine distinctly larger than the other.The frontal appendage of P.multisegmentalis tapered backwards,consisting of 22 visible podomeres;the most ventral spine is armed with 5 pairs of auxiliary spines,and podomeres 12–21 bear dorsal spines,the last podomere with 2 small distal spines.The new material provides additional evidence for our understanding of the diversity of anomalocaridids in the Cambrian.The morphology of these new finds may indicate the importance of different feeding strategies of anomalocaridids in the Cambrian ecosystem.
