Functional constraints between different types of antipredator behavior should be common,especially if they are on the opposite sides of the behavioral spectrum such as flight and post-capture immobility.We examined a...Functional constraints between different types of antipredator behavior should be common,especially if they are on the opposite sides of the behavioral spectrum such as flight and post-capture immobility.We examined a potential compromise between post-capture immobility displays and sprint speed in dice snakes(Natrix tessellata),using a field-based approach.We sampled snakes(N=238)from two populations:from a dense island population free of mammal predators,and from a less dense mainland population,preyed upon by both bird and mammal predators.We explored the effects of sexual maturity,temperature,body size,presence of palpable food in the gut,and injuries on the occurrence and duration of post-capture immobility as well as sprint speed.Our results confirm the existence of functional constraints between locomotor performance and post-capture immobility in dice snakes.Faster dice snakes start escaping promptly after release,while slower individuals utilize more passive antipredator behaviors such as death feigning.Local adaptations seem to have great influence on behavioral compromise,since the mammal-free island population exhibited a higher incidence of post-capture immobility and a significantly lower sprint speed,compared to the less dense mainland population.Additionally,immature individuals tended to avoid death feigning and their post-capture immobility lasted shorter compared to adult individuals.It remains to be seen how individuals adjust their behavior to accomodate locomotor constraints,and in which specific phases of the predator-prey interaction these adjustments occur.展开更多
Feigning madness without becoming insane is a traditional Chinese stratagem recorded in Thirty-Six Stratagems,one of the most famous military works of ancient China.It can be seen in the military history and the polit...Feigning madness without becoming insane is a traditional Chinese stratagem recorded in Thirty-Six Stratagems,one of the most famous military works of ancient China.It can be seen in the military history and the political history of ancient China.It is a high-level psychological tactic,requiring the users to have extremely strong psychological resilience and great insight.Therefore,adopting the stratagem of feigning madness without becoming insane is the game of smart people.In brief,this stratagem is a kind of psychological defense tactic,helping the users protect themselves and gain enough time to prepare for the counterattack.About this stratagem,in ancient Chinese history,there were many successful examples.At the same time,failed cases are also worth studying.As a matter of fact,this traditional stratagem can be adopted in many different fields such as military,politics,and commerce.Thus,the research about this stratagem will be a good reference for the people of modern times.展开更多
Ulysses, the towering mythological figure and the hero of the world＇s most famous epic The Odyssey, put on the pretence of madness to shirk the Trojan War. This is not mentioned in Homer, but in Fabulae by Gaius Juli...Ulysses, the towering mythological figure and the hero of the world＇s most famous epic The Odyssey, put on the pretence of madness to shirk the Trojan War. This is not mentioned in Homer, but in Fabulae by Gaius Julius Hyginus. Similarly, Hamlet put on an ＂antic disposition＂ after the ghost exhorted him to kill King Claudius. In these two cases taken from mythology and literature, and pertaining to the Classical period and the Elizabethan age respectively, intelligent characters put on the pretence of madness, in their battle with society though they are in control of their senses. It is the aim of this paper to examine the dynamics of reason and non-reason when combined and brought so close to one another, that they could be easily confounded, in light of Derrida＇s reading of Descartes＇ formulations about reason. Since the two examined works pertain to the Classical and Elizabethan ages respectively, the paper will shed light on the historical background of madness in these periods to give a broader perspective of reason and madness in these works.展开更多
Sexual differences in morphology can evolve by sexual selection and/or natural selection.In some species,only males have morphological structures that are used as weapons.Since some weapons may also be used for defens...Sexual differences in morphology can evolve by sexual selection and/or natural selection.In some species,only males have morphological structures that are used as weapons.Since some weapons may also be used for defensive purposes,males and females may behave differently towards predators.In some species of harvestmen(Arachnida and Opiliones),males have sharp apophyses("spines")on their 4th pair of legs whereas females lack them.Those apophyses are used in malemale fights and in antipredatory behaviors.The harvestmen antipredatory repertory also encompasses passive defenses such as thanatosis(death feigning),retaliation(attack on predators),and chemical defense.Due to the sexual differences on weaponry,we hypothesized that males and females of Mischonyx cuspidatus(Gonyleptidae)rely on different defensive strategies.We experimentally induced males and females to perform 3 defensive behaviors:thanatosis,pinching with legs,and chemical release.We predicted that females would engage more in passive and chemical defenses than males,whereas males would rely more on retaliation than females.As expected,females performed thanatosis more often than males.Likewise,males performed retaliation more often than females.We did not find differences in the rate of chemical defense use between the sexes.This study provides evidence that due to sexual dimorphism,alternative antipredatory behaviors may have been selected in the different sexes in M.cuspidatus.展开更多
基金supported by the Prespa-Ohrid Nature Trust and the Aage V.Jensen Foundation via PrespaNet's"Prespa Project(2021-2024)"the Rufford Foundation(grant number 30090-1)the Ministry of Science,Technological Development and Innovation of the Republic of Serbia(grant numbers451-03-0133012020-14/2627,451-03-47/2023-01/200178,451-03-47/2023-01/200007).
文摘Functional constraints between different types of antipredator behavior should be common,especially if they are on the opposite sides of the behavioral spectrum such as flight and post-capture immobility.We examined a potential compromise between post-capture immobility displays and sprint speed in dice snakes(Natrix tessellata),using a field-based approach.We sampled snakes(N=238)from two populations:from a dense island population free of mammal predators,and from a less dense mainland population,preyed upon by both bird and mammal predators.We explored the effects of sexual maturity,temperature,body size,presence of palpable food in the gut,and injuries on the occurrence and duration of post-capture immobility as well as sprint speed.Our results confirm the existence of functional constraints between locomotor performance and post-capture immobility in dice snakes.Faster dice snakes start escaping promptly after release,while slower individuals utilize more passive antipredator behaviors such as death feigning.Local adaptations seem to have great influence on behavioral compromise,since the mammal-free island population exhibited a higher incidence of post-capture immobility and a significantly lower sprint speed,compared to the less dense mainland population.Additionally,immature individuals tended to avoid death feigning and their post-capture immobility lasted shorter compared to adult individuals.It remains to be seen how individuals adjust their behavior to accomodate locomotor constraints,and in which specific phases of the predator-prey interaction these adjustments occur.
文摘Feigning madness without becoming insane is a traditional Chinese stratagem recorded in Thirty-Six Stratagems,one of the most famous military works of ancient China.It can be seen in the military history and the political history of ancient China.It is a high-level psychological tactic,requiring the users to have extremely strong psychological resilience and great insight.Therefore,adopting the stratagem of feigning madness without becoming insane is the game of smart people.In brief,this stratagem is a kind of psychological defense tactic,helping the users protect themselves and gain enough time to prepare for the counterattack.About this stratagem,in ancient Chinese history,there were many successful examples.At the same time,failed cases are also worth studying.As a matter of fact,this traditional stratagem can be adopted in many different fields such as military,politics,and commerce.Thus,the research about this stratagem will be a good reference for the people of modern times.
文摘Ulysses, the towering mythological figure and the hero of the world＇s most famous epic The Odyssey, put on the pretence of madness to shirk the Trojan War. This is not mentioned in Homer, but in Fabulae by Gaius Julius Hyginus. Similarly, Hamlet put on an ＂antic disposition＂ after the ghost exhorted him to kill King Claudius. In these two cases taken from mythology and literature, and pertaining to the Classical period and the Elizabethan age respectively, intelligent characters put on the pretence of madness, in their battle with society though they are in control of their senses. It is the aim of this paper to examine the dynamics of reason and non-reason when combined and brought so close to one another, that they could be easily confounded, in light of Derrida＇s reading of Descartes＇ formulations about reason. Since the two examined works pertain to the Classical and Elizabethan ages respectively, the paper will shed light on the historical background of madness in these periods to give a broader perspective of reason and madness in these works.
文摘Sexual differences in morphology can evolve by sexual selection and/or natural selection.In some species,only males have morphological structures that are used as weapons.Since some weapons may also be used for defensive purposes,males and females may behave differently towards predators.In some species of harvestmen(Arachnida and Opiliones),males have sharp apophyses("spines")on their 4th pair of legs whereas females lack them.Those apophyses are used in malemale fights and in antipredatory behaviors.The harvestmen antipredatory repertory also encompasses passive defenses such as thanatosis(death feigning),retaliation(attack on predators),and chemical defense.Due to the sexual differences on weaponry,we hypothesized that males and females of Mischonyx cuspidatus(Gonyleptidae)rely on different defensive strategies.We experimentally induced males and females to perform 3 defensive behaviors:thanatosis,pinching with legs,and chemical release.We predicted that females would engage more in passive and chemical defenses than males,whereas males would rely more on retaliation than females.As expected,females performed thanatosis more often than males.Likewise,males performed retaliation more often than females.We did not find differences in the rate of chemical defense use between the sexes.This study provides evidence that due to sexual dimorphism,alternative antipredatory behaviors may have been selected in the different sexes in M.cuspidatus.
