Eyespots have been shown to perform an anti-predator function by intimidating predators.However,whether predators are deterred by the eyespots’mimicking eyes of higher-order predators,or by the conspicuousness of the...Eyespots have been shown to perform an anti-predator function by intimidating predators.However,whether predators are deterred by the eyespots’mimicking eyes of higher-order predators,or by the conspicuousness of the spots,is still being debated.The anti-predator mechanism of eyespots,which involves the predator’s visual perception and cognition,urges to be examined.To explore the“eye mimicry hypothesis”and“conspicuous signal hypothesis,”we designed prey with deceptive eyespots eliciting 2-dimensional(2D)or 3-dimensional(3D)visual illusions for domestic chicks(as predators).For 2D visual illusion,we provided prey with occluded eyespots for chicks.Chicks can“complete”the occluded eyespots into a full 2D concentric circle by the amodal completion mechanism,that is,one of visual illusion.For 3D visual illusion,we created the crescent-shaped sparkles on the eyespots to simulate a visually 3D eye.Our result indicated that(1)2D:chicks hesitated more when facing preys with occluded eyespots than facing preys with broken eyespots and(2)3D:compared to prey with no-sparkle eyespots,chicks spent more time approaching prey with sparkle eyespots and were more likely to approach them tangentially.Thus,the visual illusion perceived by chicks would impact the anti-predation effectiveness of eyespots.Eyespots that more closely resemble the real eyes,especially those with 3-dimensionality,provided more effective protection.Our study supported the eye mimicry hypothesis from the perspective of visual illusion.展开更多
Group living animals form striking aggregation patterns and display synchronization,polarization,and collective intelligence.Though many col-lective behavioral studies have been conducted on small animals like insects...Group living animals form striking aggregation patterns and display synchronization,polarization,and collective intelligence.Though many col-lective behavioral studies have been conducted on small animals like insects and fish,research on large animals is still rare due to the limited availability of field collective data.We used drones to record videos and analyzed the decision-making and behavioral spatial patterns in orienta-tion of Kiang(Tibetan wild ass,Equus kiang).Leadership is unevenly distributed among Kiang,with the minority initiating majority behavior-shift decisions.Decisions of individual to join are driven by imitation between group members,and are largely dependent on the number of members who have already joined.Kiang respond to the behavior and position of neighbors through different strategies.They strongly polarize when moving,therefore adopting a linear alignment.When vigilant,orientation deviation increases as they form a tighter group.They remain scattered while feeding and,in that context,adopt a side-by-side alignment.This study reveals partially-shared decision-making among Kiang,whereby copying neighbors provides the wisdom to thrive in harsh conditions.This study also suggests that animals'spatial patterns in orientation depend largely ontheirbehavioral states inachieving synchronization.展开更多
Environmental DNA(e DNA)methods have emerged as a promising tool for studying a broad spectrum of biological taxa.However,metabarcoding studies of avian biodiversity using e DNA have received little attention.In this ...Environmental DNA(e DNA)methods have emerged as a promising tool for studying a broad spectrum of biological taxa.However,metabarcoding studies of avian biodiversity using e DNA have received little attention.In this study,we compared waterbird biodiversity derived from e DNA metabarcoding with that obtained from traditional point counting surveys at 23 sites in Tai Lake of eastern China and evaluated the accuracy of e DNA metabarcoding for waterbird community studies.The point counting method recorded a higher total number of waterbird species(22)compared to the e DNA technique(16).While e DNA achieved a 74.5%detection rate for waterbird species and was able to identify a significantly greater number of species(12.48±1.97)at each sampling site than point counting method(6.13±2.69),particularly highlighting several rare and elusive species,it failed to detect some species commonly observed by the point counting method.The alpha diversity analysis revealed no significant differences in waterbird diversity between the e DNA method and the point counting method,except that the e DNA method exhibited lower Pielou evenness.Waterbird e DNA sequencing abundance correlated significantly with species occurrence,whereas Spearman's analysis indicated no significant difference between e DNA sequence abundance and species abundance from the point counting method.e DNA method detected no significant difference in waterbird composition between sampling sites,while the point counting method revealed significant differences.Consequently,e DNA is an effective complementary tool for assessing the diversity of wintering waterbirds in lakes,though it is unable to capture the full diversity of waterbird communities.It is crucial to develop sampling strategies that comprehensively monitor species composition and integrate e DNA with traditional survey methods for accurate evaluation of community structure.展开更多
The behavioral responses of birds to urban environments are crucial for their ability to thrive within city landscapes.Various urban birds have demonstrated the capacity to exploit artificial structures as nesting sit...The behavioral responses of birds to urban environments are crucial for their ability to thrive within city landscapes.Various urban birds have demonstrated the capacity to exploit artificial structures as nesting sites due to the limited availability of natural options.This review examines the current state of urban bird nesting behaviors on manmade structures and highlights directions for future research.Nest types frequently observed on these structures include woven,cavity,ground,and mud nests.These adaptive behaviors increase nesting opportunities and improve reproductive success,although they may heighten vulnerability to ecological traps.Proximity to human habitats can promote conservation awareness but also presents potential economic and health-related challenges.Therefore,applying diverse strategies is essential for effectively managing and protecting nests on man-made structures across various circumstances.There is also a need for thorough,long-term studies on the ecological and evolutionary impacts of nest building on artificial structures and the mechanisms influencing nestsite selection.Furthermore,exploring innovative approaches that combine policy implementation and citizen science will be vital for advancing human-bird coexistence.展开更多
基金financially supported by the National Natural Science Foundation of China(Grant No.32471564)。
文摘Eyespots have been shown to perform an anti-predator function by intimidating predators.However,whether predators are deterred by the eyespots’mimicking eyes of higher-order predators,or by the conspicuousness of the spots,is still being debated.The anti-predator mechanism of eyespots,which involves the predator’s visual perception and cognition,urges to be examined.To explore the“eye mimicry hypothesis”and“conspicuous signal hypothesis,”we designed prey with deceptive eyespots eliciting 2-dimensional(2D)or 3-dimensional(3D)visual illusions for domestic chicks(as predators).For 2D visual illusion,we provided prey with occluded eyespots for chicks.Chicks can“complete”the occluded eyespots into a full 2D concentric circle by the amodal completion mechanism,that is,one of visual illusion.For 3D visual illusion,we created the crescent-shaped sparkles on the eyespots to simulate a visually 3D eye.Our result indicated that(1)2D:chicks hesitated more when facing preys with occluded eyespots than facing preys with broken eyespots and(2)3D:compared to prey with no-sparkle eyespots,chicks spent more time approaching prey with sparkle eyespots and were more likely to approach them tangentially.Thus,the visual illusion perceived by chicks would impact the anti-predation effectiveness of eyespots.Eyespots that more closely resemble the real eyes,especially those with 3-dimensionality,provided more effective protection.Our study supported the eye mimicry hypothesis from the perspective of visual illusion.
基金supported by Tibet Major Science and Technology Project(XZ201901-GA-06)National Natural Science Foundation of China(32101237&41871294)National key research and development program(2022YFC3202104).
文摘Group living animals form striking aggregation patterns and display synchronization,polarization,and collective intelligence.Though many col-lective behavioral studies have been conducted on small animals like insects and fish,research on large animals is still rare due to the limited availability of field collective data.We used drones to record videos and analyzed the decision-making and behavioral spatial patterns in orienta-tion of Kiang(Tibetan wild ass,Equus kiang).Leadership is unevenly distributed among Kiang,with the minority initiating majority behavior-shift decisions.Decisions of individual to join are driven by imitation between group members,and are largely dependent on the number of members who have already joined.Kiang respond to the behavior and position of neighbors through different strategies.They strongly polarize when moving,therefore adopting a linear alignment.When vigilant,orientation deviation increases as they form a tighter group.They remain scattered while feeding and,in that context,adopt a side-by-side alignment.This study reveals partially-shared decision-making among Kiang,whereby copying neighbors provides the wisdom to thrive in harsh conditions.This study also suggests that animals'spatial patterns in orientation depend largely ontheirbehavioral states inachieving synchronization.
基金funded by the National Key Research and Development Program of China(Award Number:2022YFC3202104)。
文摘Environmental DNA(e DNA)methods have emerged as a promising tool for studying a broad spectrum of biological taxa.However,metabarcoding studies of avian biodiversity using e DNA have received little attention.In this study,we compared waterbird biodiversity derived from e DNA metabarcoding with that obtained from traditional point counting surveys at 23 sites in Tai Lake of eastern China and evaluated the accuracy of e DNA metabarcoding for waterbird community studies.The point counting method recorded a higher total number of waterbird species(22)compared to the e DNA technique(16).While e DNA achieved a 74.5%detection rate for waterbird species and was able to identify a significantly greater number of species(12.48±1.97)at each sampling site than point counting method(6.13±2.69),particularly highlighting several rare and elusive species,it failed to detect some species commonly observed by the point counting method.The alpha diversity analysis revealed no significant differences in waterbird diversity between the e DNA method and the point counting method,except that the e DNA method exhibited lower Pielou evenness.Waterbird e DNA sequencing abundance correlated significantly with species occurrence,whereas Spearman's analysis indicated no significant difference between e DNA sequence abundance and species abundance from the point counting method.e DNA method detected no significant difference in waterbird composition between sampling sites,while the point counting method revealed significant differences.Consequently,e DNA is an effective complementary tool for assessing the diversity of wintering waterbirds in lakes,though it is unable to capture the full diversity of waterbird communities.It is crucial to develop sampling strategies that comprehensively monitor species composition and integrate e DNA with traditional survey methods for accurate evaluation of community structure.
基金supported by the National Key Research and Development Program(2022YFC3202104)National Natural Science Foundation of China(32101237)Natural Science Foundation of Jiangsu Province(BK20211151)。
文摘The behavioral responses of birds to urban environments are crucial for their ability to thrive within city landscapes.Various urban birds have demonstrated the capacity to exploit artificial structures as nesting sites due to the limited availability of natural options.This review examines the current state of urban bird nesting behaviors on manmade structures and highlights directions for future research.Nest types frequently observed on these structures include woven,cavity,ground,and mud nests.These adaptive behaviors increase nesting opportunities and improve reproductive success,although they may heighten vulnerability to ecological traps.Proximity to human habitats can promote conservation awareness but also presents potential economic and health-related challenges.Therefore,applying diverse strategies is essential for effectively managing and protecting nests on man-made structures across various circumstances.There is also a need for thorough,long-term studies on the ecological and evolutionary impacts of nest building on artificial structures and the mechanisms influencing nestsite selection.Furthermore,exploring innovative approaches that combine policy implementation and citizen science will be vital for advancing human-bird coexistence.
