西藏拉萨越冬黑颈鹤家庭群的警戒同步性
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摘要
以往关于动物警戒行为的研究多以经典随机独立模型为基础,然而,近期一些理论和实证研究则向该模型发出了挑战。根据警戒行为同步性程度的不同,集体警戒可能存在基于模仿的同步警戒和避免重复的协调警戒两种模式。研究了中国雅鲁藏布江自然保护区越冬黑颈鹤家庭群的警戒行为,通过独立样本t检验验证由于年龄和是否携幼所导致的个体警戒水平的差异,通过单因素方差分析比较不同类型家庭群的集体警戒水平,通过配对t检验比较集体警戒的实际观测值和独立假设下的预期值从而确定越冬黑颈鹤家庭群的警戒同步性。结果表明家庭群中的幼年黑颈鹤警戒行为时间显著低于成年黑颈鹤,但幼鹤的存在对成鹤的警戒水平没有显著影响。不同类型黑颈鹤家庭群的集体警戒水平没有差异,但并未如预期表现为同步警戒。警戒行为模式是动物在特定环境中的适应性表现,越冬黑颈鹤生境中不存在落后目标策略的捕食者和高强度的捕食风险,因而可能不足以诱发以降低捕食风险为主要功能的高强度的警戒行为同步性;同时,在资源匮乏的冬季对食物获取的优先性可能也削弱了对同步警戒的需求。
Most previous studies of animal vigilance behavior have been based on Pulliam' s classical model,which emphasizes that individuals' vigilance occurs independently and is,therefore,unaffected by the vigilant state of other individuals in the same group. However,recent theoretical and empirical studies have challenged this model and have reported that,depending on the degree of vigilance synchronization,the collective vigilance can be either imitation-based synchronized vigilance or coordinated vigilance that avoids overlapping bouts. In the present study,we observed the vigilance behavior of wintering black-necked crane( Grus nigricollis) families in the Yarlung Zangbo River Nature Reserve.The black-necked crane is a globally endangered species that lives exclusively in the Tibetan Plateau. We captured videos in the field and then scanned 30-s intervals of the footage to record individual and collective vigilance behavior. Further,we used Student's t-test to determine the effects of age and predation vulnerability at the individual level. The results indicated that juveniles spent significantly less time in vigilance than their parents,mainly owing to lack of vigilance and feeding experience,which necessitates juveniles to spend more time feeding to meet their energetic and developmental requirements.However,the presence of juveniles in family groups had no effect on the vigilance of adult cranes,and according to one-wayANOVA,there was no difference in the collective vigilance of different types of black-necked crane family groups.Meanwhile,a paired t-test,which was used to compare the observed and predicted collective vigilance values in order to determine the vigilance synchronization of wintering black-necked cranes,indicated that there was no synchronization tendency. The difference between the predicted and observed values was not significant between adult cranes,all family members,or adults and juveniles. Vigilance patterns are adaptive behaviors of animals in particular environments. In the wintering habitat of black-necked cranes,there is no targeting predator,and the black-necked cranes are generally protected as a symbol of auspiciousness in the Tibetan area. Although black-necked cranes that forage in farmland are inevitably disturbed by humans,the degree of interference and predation risk is insufficient to induce high-intensity vigilance synchronization that mainly function for reducing predator risk. In addition,when food availability becomes a key factor for survival,energy acquisition takes precedence over safety assurance,and as a result,the need for synchronized vigilance is reduced. Studying vigilance synchronization can reveal the vigilance pattern of black-necked cranes in the field and provide meaningful information for their management and conservation.
Most previous studies of animal vigilance behavior have been based on Pulliam' s classical model,which emphasizes that individuals' vigilance occurs independently and is,therefore,unaffected by the vigilant state of other individuals in the same group. However,recent theoretical and empirical studies have challenged this model and have reported that,depending on the degree of vigilance synchronization,the collective vigilance can be either imitation-based synchronized vigilance or coordinated vigilance that avoids overlapping bouts. In the present study,we observed the vigilance behavior of wintering black-necked crane( Grus nigricollis) families in the Yarlung Zangbo River Nature Reserve.The black-necked crane is a globally endangered species that lives exclusively in the Tibetan Plateau. We captured videos in the field and then scanned 30-s intervals of the footage to record individual and collective vigilance behavior. Further,we used Student's t-test to determine the effects of age and predation vulnerability at the individual level. The results indicated that juveniles spent significantly less time in vigilance than their parents,mainly owing to lack of vigilance and feeding experience,which necessitates juveniles to spend more time feeding to meet their energetic and developmental requirements.However,the presence of juveniles in family groups had no effect on the vigilance of adult cranes,and according to one-wayANOVA,there was no difference in the collective vigilance of different types of black-necked crane family groups.Meanwhile,a paired t-test,which was used to compare the observed and predicted collective vigilance values in order to determine the vigilance synchronization of wintering black-necked cranes,indicated that there was no synchronization tendency. The difference between the predicted and observed values was not significant between adult cranes,all family members,or adults and juveniles. Vigilance patterns are adaptive behaviors of animals in particular environments. In the wintering habitat of black-necked cranes,there is no targeting predator,and the black-necked cranes are generally protected as a symbol of auspiciousness in the Tibetan area. Although black-necked cranes that forage in farmland are inevitably disturbed by humans,the degree of interference and predation risk is insufficient to induce high-intensity vigilance synchronization that mainly function for reducing predator risk. In addition,when food availability becomes a key factor for survival,energy acquisition takes precedence over safety assurance,and as a result,the need for synchronized vigilance is reduced. Studying vigilance synchronization can reveal the vigilance pattern of black-necked cranes in the field and provide meaningful information for their management and conservation.
引文
[1]Childress M J,Lung M A.Predation risk,gender and the group size effect:does elk vigilance depend upon the behaviour of conspecifics?Animal Behaviour,2003,66(2):389-398.
[2]Gaynor K M,Cords M.Antipredator and social monitoring functions of vigilance behaviour in blue monkeys.Animal Behaviour,2012,84(3):531-537.
[3]Pulliam H R.On the advantages of flocking.Journal of Theoretical Biology,1973,38(2):419-422.
[4]Fernández-Juricic E,Siller S,Kacelnik A.Flock density,social foraging,and scanning:an experiment with starlings.Behavioral Ecology,2004,15(3):371-379.
[5]Sirot E.Social information,antipredatory vigilance and flight in bird flocks.Animal Behaviour,2006,72(2):373-382.
[6]Roth II T C,Cox J G,Lima S L.The use and transfer of information about predation risk in flocks of wintering finches.Ethology,2008,114(12):1218-1226.
[7]Beauchamp G.Sleeping gulls monitor the vigilance behaviour of their neighbours.Biology Letters,2009,5(1):9-11.
[8]Pays O,Goulard M,Blomberg S P,Goldizen A W,Sirot E,Jarman P J.The effect of social facilitation on vigilance in the eastern gray kangaroo,Macropus giganteus.Behavioral Ecology,2009,20(3):469-477.
[9]Beauchamp G,Alexander P,Jovani R.Consistent waves of collective vigilance in groups using public information about predation risk.Behavioral Ecology,2011,23(2):368-374.
[10]Xu F,Ma M,Yang W K,Blank D,Ding P,Zhang T.Vigilance in Black-necked Cranes:effects of predation vulnerability and flock size.The Wilson Journal of Ornithology,2013,125(1):208-212.
[11]Kuang F L,Li F S,Liu N,Li F Q.Effect of flock size and position in flock on vigilance of black-necked cranes(Grus nigricollis)in winter.Waterbirds,2014,37(1):94-98.
[12]Yang L,Zhuom C J,Li Z Q.Group size effects on vigilance of wintering black-necked cranes(Grus nigricollis)in Tibet,China.Waterbirds,2016,39(1):108-113.
[13]Ge C,Beauchamp G,Li Z Q.Coordination and synchronisation of anti-predation vigilance in two crane species.PLo S One,2011,6(10):e26447.
[14]Li C L,Beauchamp G,Wang Z,Cui P.Collective vigilance in the wintering hooded crane:the role of flock size and anthropogenic disturbances in a human‐dominated landscape.Ethology,2016,122(12):999-1008.
[15]Bishop M A,Zhuoma C,Song Y L,Harkness J,Gu B Y.Winter habitat use by black-necked cranes Grus nigricollis in Tibet.Wildfowl,1998,49:228-241.
[16]仓决卓玛,杨乐,李建川.西藏黑颈鹤越冬期昼间行为的时间分配.野生动物,2008,29(1):15-20.
[17]仓决卓玛,杨乐,李建川,央金卓嘎.西藏黑颈鹤的保护与研究现状.四川动物,2008,27(3):449-453.
[18]李忠秋.丹顶鹤行为观察的适宜距离:简评观察者效应(英文).Chinese Birds,2011,2(3):147-151.
[19]Pays O,Renaud P C,Loisel P,Petit M,Gerard J F,Jarman P J.Prey synchronize their vigilant behaviour with other group members.Proceedings of the Royal Society B:Biological Sciences,2007,274(1615):1287-1291.
[20]Podgórski T,De Jong S,Bubnicki J W,Kuijper D P J,Churski M,Jdrzejewska B.Drivers of synchronized vigilance in wild boar groups.Behavioral Ecology,2016,27(4):1097-1103.
[21]王凯,杨晓君,赵健林,余红忠,闵龙.云南纳帕海越冬黑颈鹤日间行为模式与年龄和集群的关系.动物学研究,2009,30(1):74-82.
[22]Li Z Q,Wang Z,Ge C.Time budgets of wintering red-crowned cranes:effects of habitat,age and family size.Wetlands,2013,33(2):227-232.
[23]Li C L,Zhou L Z,Xu L,Zhao N N,Beauchamp G.Vigilance and activity time-budget adjustments of wintering hooded cranes,Grus monacha,in human-dominated foraging habitats.PLo S One,2015,10(3):e0118928.
[24]Weathers W W,Sullivan K A.Juvenile foraging proficiency,parental effort,and avian reproductive success.Ecological Monographs,1989,59(3):223-246.
[25]Wang Z,Li Z Q,Beauchamp G,Jiang Z G.Flock size and human disturbance affect vigilance of endangered red-crowned cranes(Grus japonensis).Biological Conservation,2011,144(1):101-105.
[26]Pays O,Sirot E,Fritz H.Collective vigilance in the greater kudu:towards a better understanding of synchronization patterns.Ethology,2012,118(1):1-9.
[27]Pays O,Jarman P J,Loisel P,Gerard J F.Coordination,independence or synchronization of individual vigilance in the eastern grey kangaroo?Animal Behaviour,2007,73(4):595-604.
[28]Quinn J L,Cresswell W.Escape response delays in wintering redshank,Tringa totanus,flocks:perceptual limits and economic decisions.Animal Behaviour,2005,69(6):1285-1292.
[29]Rodríguez-Gironés M A,Vásquez R A.Evolutionary stability of vigilance coordination among social foragers.Proceedings of the Royal Society B:Biological Sciences,2002,269(1502):1803-1810.
[30]Sirot E,Touzalin F.Coordination and synchronization of vigilance in groups of prey:the role of collective detection and predators'preference for stragglers.The American Naturalist,2009,173(1):47-59.
[31]Ward P I.Why birds in flocks do not coordinate their vigilance periods.Journal of Theoretical Biology,1985,114(3):383-385.
[32]Lima S L.Back to the basics of anti-predatory vigilance:the group-Size effect.Animal Behaviour,1995,49(1):11-20.
[33]Ruxton G D,Roberts G.Are vigilance sequences a consequence of intrinsic chaos or external changes?Animal Behaviour,1999,57(2):493-495.
[34]Beauchamp G,Ruxton G D.Changes in vigilance with group size under scramble competition.The American Naturalist,2003,161(4):672-675.
[35]Bishop M A,Li F S.李凤山.农业耕作活动对西藏越冬黑颈鹤食性及食物可获得性的影响.生物多样性,2002,10(4):393-398.
[36]Hilton G M,Cresswell W,Ruxton G D.Intraflock variation in the speed of escape-flight response on attack by an avian predator.Behavioral Ecology,1999,10(4):391-395.
[37]Bednekoff P A,Lima S L.Re-examining safety in numbers:interactions between risk dilution and collective detection depend upon predator targeting behaviour.Proceedings of the Royal Society B:Biological Sciences,1998,265(1409):2021-2026.
[38]Sirot E.Negotiation may lead selfish individuals to cooperate:the example of the collective vigilance game.Proceedings of the Royal Society B:Biological Sciences,2012,279(1739):2862-2867.
[39]李筑眉,李凤山.黑颈鹤研究.上海:上海科技教育出版社,2005:13.
[2]Gaynor K M,Cords M.Antipredator and social monitoring functions of vigilance behaviour in blue monkeys.Animal Behaviour,2012,84(3):531-537.
[3]Pulliam H R.On the advantages of flocking.Journal of Theoretical Biology,1973,38(2):419-422.
[4]Fernández-Juricic E,Siller S,Kacelnik A.Flock density,social foraging,and scanning:an experiment with starlings.Behavioral Ecology,2004,15(3):371-379.
[5]Sirot E.Social information,antipredatory vigilance and flight in bird flocks.Animal Behaviour,2006,72(2):373-382.
[6]Roth II T C,Cox J G,Lima S L.The use and transfer of information about predation risk in flocks of wintering finches.Ethology,2008,114(12):1218-1226.
[7]Beauchamp G.Sleeping gulls monitor the vigilance behaviour of their neighbours.Biology Letters,2009,5(1):9-11.
[8]Pays O,Goulard M,Blomberg S P,Goldizen A W,Sirot E,Jarman P J.The effect of social facilitation on vigilance in the eastern gray kangaroo,Macropus giganteus.Behavioral Ecology,2009,20(3):469-477.
[9]Beauchamp G,Alexander P,Jovani R.Consistent waves of collective vigilance in groups using public information about predation risk.Behavioral Ecology,2011,23(2):368-374.
[10]Xu F,Ma M,Yang W K,Blank D,Ding P,Zhang T.Vigilance in Black-necked Cranes:effects of predation vulnerability and flock size.The Wilson Journal of Ornithology,2013,125(1):208-212.
[11]Kuang F L,Li F S,Liu N,Li F Q.Effect of flock size and position in flock on vigilance of black-necked cranes(Grus nigricollis)in winter.Waterbirds,2014,37(1):94-98.
[12]Yang L,Zhuom C J,Li Z Q.Group size effects on vigilance of wintering black-necked cranes(Grus nigricollis)in Tibet,China.Waterbirds,2016,39(1):108-113.
[13]Ge C,Beauchamp G,Li Z Q.Coordination and synchronisation of anti-predation vigilance in two crane species.PLo S One,2011,6(10):e26447.
[14]Li C L,Beauchamp G,Wang Z,Cui P.Collective vigilance in the wintering hooded crane:the role of flock size and anthropogenic disturbances in a human‐dominated landscape.Ethology,2016,122(12):999-1008.
[15]Bishop M A,Zhuoma C,Song Y L,Harkness J,Gu B Y.Winter habitat use by black-necked cranes Grus nigricollis in Tibet.Wildfowl,1998,49:228-241.
[16]仓决卓玛,杨乐,李建川.西藏黑颈鹤越冬期昼间行为的时间分配.野生动物,2008,29(1):15-20.
[17]仓决卓玛,杨乐,李建川,央金卓嘎.西藏黑颈鹤的保护与研究现状.四川动物,2008,27(3):449-453.
[18]李忠秋.丹顶鹤行为观察的适宜距离:简评观察者效应(英文).Chinese Birds,2011,2(3):147-151.
[19]Pays O,Renaud P C,Loisel P,Petit M,Gerard J F,Jarman P J.Prey synchronize their vigilant behaviour with other group members.Proceedings of the Royal Society B:Biological Sciences,2007,274(1615):1287-1291.
[20]Podgórski T,De Jong S,Bubnicki J W,Kuijper D P J,Churski M,Jdrzejewska B.Drivers of synchronized vigilance in wild boar groups.Behavioral Ecology,2016,27(4):1097-1103.
[21]王凯,杨晓君,赵健林,余红忠,闵龙.云南纳帕海越冬黑颈鹤日间行为模式与年龄和集群的关系.动物学研究,2009,30(1):74-82.
[22]Li Z Q,Wang Z,Ge C.Time budgets of wintering red-crowned cranes:effects of habitat,age and family size.Wetlands,2013,33(2):227-232.
[23]Li C L,Zhou L Z,Xu L,Zhao N N,Beauchamp G.Vigilance and activity time-budget adjustments of wintering hooded cranes,Grus monacha,in human-dominated foraging habitats.PLo S One,2015,10(3):e0118928.
[24]Weathers W W,Sullivan K A.Juvenile foraging proficiency,parental effort,and avian reproductive success.Ecological Monographs,1989,59(3):223-246.
[25]Wang Z,Li Z Q,Beauchamp G,Jiang Z G.Flock size and human disturbance affect vigilance of endangered red-crowned cranes(Grus japonensis).Biological Conservation,2011,144(1):101-105.
[26]Pays O,Sirot E,Fritz H.Collective vigilance in the greater kudu:towards a better understanding of synchronization patterns.Ethology,2012,118(1):1-9.
[27]Pays O,Jarman P J,Loisel P,Gerard J F.Coordination,independence or synchronization of individual vigilance in the eastern grey kangaroo?Animal Behaviour,2007,73(4):595-604.
[28]Quinn J L,Cresswell W.Escape response delays in wintering redshank,Tringa totanus,flocks:perceptual limits and economic decisions.Animal Behaviour,2005,69(6):1285-1292.
[29]Rodríguez-Gironés M A,Vásquez R A.Evolutionary stability of vigilance coordination among social foragers.Proceedings of the Royal Society B:Biological Sciences,2002,269(1502):1803-1810.
[30]Sirot E,Touzalin F.Coordination and synchronization of vigilance in groups of prey:the role of collective detection and predators'preference for stragglers.The American Naturalist,2009,173(1):47-59.
[31]Ward P I.Why birds in flocks do not coordinate their vigilance periods.Journal of Theoretical Biology,1985,114(3):383-385.
[32]Lima S L.Back to the basics of anti-predatory vigilance:the group-Size effect.Animal Behaviour,1995,49(1):11-20.
[33]Ruxton G D,Roberts G.Are vigilance sequences a consequence of intrinsic chaos or external changes?Animal Behaviour,1999,57(2):493-495.
[34]Beauchamp G,Ruxton G D.Changes in vigilance with group size under scramble competition.The American Naturalist,2003,161(4):672-675.
[35]Bishop M A,Li F S.李凤山.农业耕作活动对西藏越冬黑颈鹤食性及食物可获得性的影响.生物多样性,2002,10(4):393-398.
[36]Hilton G M,Cresswell W,Ruxton G D.Intraflock variation in the speed of escape-flight response on attack by an avian predator.Behavioral Ecology,1999,10(4):391-395.
[37]Bednekoff P A,Lima S L.Re-examining safety in numbers:interactions between risk dilution and collective detection depend upon predator targeting behaviour.Proceedings of the Royal Society B:Biological Sciences,1998,265(1409):2021-2026.
[38]Sirot E.Negotiation may lead selfish individuals to cooperate:the example of the collective vigilance game.Proceedings of the Royal Society B:Biological Sciences,2012,279(1739):2862-2867.
[39]李筑眉,李凤山.黑颈鹤研究.上海:上海科技教育出版社,2005:13.