Functionally referential signals are a complex form of communication that conveys information about the external environment.Such signals have been found in a range of mammal and bird species and have helped us unders...Functionally referential signals are a complex form of communication that conveys information about the external environment.Such signals have been found in a range of mammal and bird species and have helped us understand the complexities of animal communication.Corvids are well known for their extraordinary cognitive abilities,but relatively little attention has been paid to their vocal function.Here,we investigated the functionally referential signals of a cooperatively breeding corvid species,Azure-winged Magpie(Cyanopica cyanus).Through field observations,we suggest that Azure-winged Magpie uses referential alarm calls to distinguish two types of threats:’rasp’ calls for terrestrial threats and ’chatter’ calls for aerial threats.A playback experiment revealed that Azure-winged Magpies responded to the two call types with qualitatively different behaviors.They sought cover by flying into the bushes in response to the ’chatter’ calls,and flew to or stayed at higher positions in response to ’rasp’ calls,displaying a shorter response time to ’chatter’ calls.Significant differences in acoustic structure were found between the two types of calls.Given the extensive cognitive abilities of corvids and the fact that referential signals were once thought to be unique to primates,these findings are important for expanding our understanding of social communication and language evolution.展开更多
Recognition and rejection of foreign eggs are effective defense of hosts against brood parasitism.However,brood parasitism can impose various selection pressures on different geographic populations of the same host sp...Recognition and rejection of foreign eggs are effective defense of hosts against brood parasitism.However,brood parasitism can impose various selection pressures on different geographic populations of the same host species.In a multiple cuckoo system in China,Azure-winged Magpies(Cyanopica cyanus)are parasitized by both Indian Cuckoos(Cuculus micropterus)and Asian Koels(Eudynamys scolopaceus).In this study,egg recognition ability and recognition mechanism of the Azure-winged Magpie were investigated using a population in Fusong,southeastern Jilin,China.The results showed that 55.6%(20/36)of the Azure-winged Magpies correctly rejected quail(Coturnix japonica)eggs in their nests,while 13.9%(5/36)of the individuals experienced rejection costs by wrongly rejecting their own eggs.Azure-winged Magpies could accurately reject the experimental eggs when the number of such eggs in the nests was the same as that of the magpie eggs.However,Azure-winged Magpies do not recognize and reject conspecific eggs(0/28).The present study indicates that the Azure-winged Magpie has moderate egg recognition ability toward non-mimetic quail eggs and shows a true recognition mechanism with rejecting foreign eggs by accurately recognizing their own eggs.However,they cannot recognize conspecific eggs.展开更多
String-pulling is one of the most widely used paradigms in an imal cog nition research. We in vestigated how azure-wi nged magpies Cyanopica cyan us solve multiple-string problems that they have never encountered befo...String-pulling is one of the most widely used paradigms in an imal cog nition research. We in vestigated how azure-wi nged magpies Cyanopica cyan us solve multiple-string problems that they have never encountered before. In Experiment 1, the strings were arranged in parallel, slanted, or crossed to investigate what rules azure-winged magpies use to solve multiple spatial relations of strings. Experiment 2 assessed whether the subjects understood the connection between the string and the bait while taking advantage of broken strings. In Experiment 3, the subjects were confronted with strings of different lengths attached to rewards in order to explore whether the string length, as a proxy for the pulling efficiency or reward distanee, was crucial for the birds' choice of which string to pull. Gen erally, the birds were successful in tasks where the reward was close to the correct string's end, and they relied on a "proximity rule" in most cases. The results showed that azure-winged magpies had a partial understanding of the physical principles underlying the string-pulling but were stumped by complex spatial relations. They likely relied on simple strategies such as the proximity rule to solve the tasks. The effects of in dividual difference and experiential learning on string-pulling performance are also discussed.展开更多
基金funded by the National Natural Science Foundation of China (Grant No. 32170516, 31872243 to Y.Z.)。
文摘Functionally referential signals are a complex form of communication that conveys information about the external environment.Such signals have been found in a range of mammal and bird species and have helped us understand the complexities of animal communication.Corvids are well known for their extraordinary cognitive abilities,but relatively little attention has been paid to their vocal function.Here,we investigated the functionally referential signals of a cooperatively breeding corvid species,Azure-winged Magpie(Cyanopica cyanus).Through field observations,we suggest that Azure-winged Magpie uses referential alarm calls to distinguish two types of threats:’rasp’ calls for terrestrial threats and ’chatter’ calls for aerial threats.A playback experiment revealed that Azure-winged Magpies responded to the two call types with qualitatively different behaviors.They sought cover by flying into the bushes in response to the ’chatter’ calls,and flew to or stayed at higher positions in response to ’rasp’ calls,displaying a shorter response time to ’chatter’ calls.Significant differences in acoustic structure were found between the two types of calls.Given the extensive cognitive abilities of corvids and the fact that referential signals were once thought to be unique to primates,these findings are important for expanding our understanding of social communication and language evolution.
基金funded by Key R&D projects in Ningxia (talent introduction project,2021BEB04015)Fundamental Research Funds for Central Universities,North Minzu University (2021KYQD05)+1 种基金supported by the National Natural Science Foundation of China (Nos.32160242 to JL,31960105 and 32260253 to LW,31970427 and32270526 to WL)supported by the specific research fund of The Innovation Platform for Academicians of Hainan Province
文摘Recognition and rejection of foreign eggs are effective defense of hosts against brood parasitism.However,brood parasitism can impose various selection pressures on different geographic populations of the same host species.In a multiple cuckoo system in China,Azure-winged Magpies(Cyanopica cyanus)are parasitized by both Indian Cuckoos(Cuculus micropterus)and Asian Koels(Eudynamys scolopaceus).In this study,egg recognition ability and recognition mechanism of the Azure-winged Magpie were investigated using a population in Fusong,southeastern Jilin,China.The results showed that 55.6%(20/36)of the Azure-winged Magpies correctly rejected quail(Coturnix japonica)eggs in their nests,while 13.9%(5/36)of the individuals experienced rejection costs by wrongly rejecting their own eggs.Azure-winged Magpies could accurately reject the experimental eggs when the number of such eggs in the nests was the same as that of the magpie eggs.However,Azure-winged Magpies do not recognize and reject conspecific eggs(0/28).The present study indicates that the Azure-winged Magpie has moderate egg recognition ability toward non-mimetic quail eggs and shows a true recognition mechanism with rejecting foreign eggs by accurately recognizing their own eggs.However,they cannot recognize conspecific eggs.
基金National Natural Science Foundation of China (no. 31772470, J1210026)Project of National Biodiversity Observation Network-Bird (2016-2018).
文摘String-pulling is one of the most widely used paradigms in an imal cog nition research. We in vestigated how azure-wi nged magpies Cyanopica cyan us solve multiple-string problems that they have never encountered before. In Experiment 1, the strings were arranged in parallel, slanted, or crossed to investigate what rules azure-winged magpies use to solve multiple spatial relations of strings. Experiment 2 assessed whether the subjects understood the connection between the string and the bait while taking advantage of broken strings. In Experiment 3, the subjects were confronted with strings of different lengths attached to rewards in order to explore whether the string length, as a proxy for the pulling efficiency or reward distanee, was crucial for the birds' choice of which string to pull. Gen erally, the birds were successful in tasks where the reward was close to the correct string's end, and they relied on a "proximity rule" in most cases. The results showed that azure-winged magpies had a partial understanding of the physical principles underlying the string-pulling but were stumped by complex spatial relations. They likely relied on simple strategies such as the proximity rule to solve the tasks. The effects of in dividual difference and experiential learning on string-pulling performance are also discussed.
