Most studies exploring abilities of hosts to detect brood parasitism are based on detecting colour and/or pattern differences among parasitic and host eggs or nestlings,while only few were focused on size differences....Most studies exploring abilities of hosts to detect brood parasitism are based on detecting colour and/or pattern differences among parasitic and host eggs or nestlings,while only few were focused on size differences.True recognition and recognition by discordancy are used to explain cognitive mechanisms of host egg recognition;however,only a few studies have found that hosts use recognition by discordancy.This study investigated:1)whether egg and nestling recognitions in the Crested Myna(Acridotheres cristatellus) are based on size cues;2)whether the egg cognitive mechanism is recognition by discordancy based on size cues;and 3) whether the longer the experiment time,the higher the egg recognition rate.Our results showed that the Crested Myna uses egg or nestling size as a recognition cue while the egg and nestling colour and patterning are not associated with egg or nestling rejection,thus the cognitive mechanism of egg recognition in the Crested Myna is recognition by discordancy based on egg size cues.Furthermore,there is a rejection delay in time of egg rejection behaviour of the Crested Myna.Therefore,we suggest that the periodicity of egg rejection experiments could be appropriately extended,especially for species with relatively low egg recognition ability.展开更多
Background:Nest parasitism by cuckoos(Cuculus spp.)results in enormous reproductive failure and forces hosts to evolve antiparasitic strategies,i.e.,recognition of own eggs and rejection of cuckoo eggs.There are often...Background:Nest parasitism by cuckoos(Cuculus spp.)results in enormous reproductive failure and forces hosts to evolve antiparasitic strategies,i.e.,recognition of own eggs and rejection of cuckoo eggs.There are often sexual conflicts between male and female individuals in the expression of antiparasitic behavior due to the differences in reproductive inputs and division of labor.Methods:By adding a foreign egg made of blue soft clay to the host nest during early incubation period in the field,and by removing several host eggs and adding experimental eggs to control the proportion of two egg types in the nest,we examined egg rejection ability,egg recognition mechanism and sexual difference in egg rejection of the Oriental Reed Warbler(Acrocephalus orientalis),one of the major hosts of Common Cuckoos(Cuculus canorus).Results:Our results indicated that Oriental Reed Warblers can recognize and reject nearly 100%(73/75)of the nonmimetic eggs made of blue soft clay,and they could reject foreign eggs with 100%accuracy,regardless of the ratio of experimental eggs and its own eggs in the nest.Furthermore,all cases of egg rejections recorded by videos were only carried out by females.Conclusions:Oriental Reed Warblers have a high egg recognition ability and show a true recognition mechanism.Only female warblers perform egg rejection,suggesting that the sex for host egg incubation seems to play an important role in the evolution of egg recognition mechanisms.展开更多
In the co-evolutionary system of avian brood parasitism,egg recognition and rejection are common and generally act as effective anti-parasitic adaptations by hosts.Accordingly,most studies have examined the role of pa...In the co-evolutionary system of avian brood parasitism,egg recognition and rejection are common and generally act as effective anti-parasitic adaptations by hosts.Accordingly,most studies have examined the role of parasite egg colors and markings in detection cues in hosts;however,studies focusing on the effects of egg size and quantity are relatively scarce and have mostly concentrated on the hosts of parasitic cowbirds.Here,we studied the egg recognition behaviors of a potential host of the Common Cuckoo(Cuculus canorus)—the Green-backed Tit(Parus monticolus),to determine:(1)whether the host uses the sizes of parasite eggs and/or the quantity contrast between parasite and host eggs as cues for recognition,(2)whether the host employs the template or discordant recognition mechanism for egg recognition,and(3)whether the size and quantity of parasite eggs affect the egg rejection modes of the hosts.The results indicate that Green-backed Tits did not use parasite egg size as a primary cue for egg recognition.We hypothesized that both visual and tactile detection might be involved in egg recognition by Green-backed Tits and suggest further studies after controlling for nest light conditions.Differences in egg quantity between parasites and hosts were not used as cues for egg recognition because the hosts employed the template mechanism rather than discordance to recognize parasite eggs.However,both the relative sizes and quantity of parasite and host eggs significantly affected the rejection modes of parasite eggs,and larger or more parasite eggs triggered higher probabilities of nest desertion in hosts.展开更多
With the knowledge that cuckoos and cowbirds lay their eggs parasitically,and that some hosts eject parasitic eggs,ornithologists began to ponder the question of how host females discriminate between a foreign egg and...With the knowledge that cuckoos and cowbirds lay their eggs parasitically,and that some hosts eject parasitic eggs,ornithologists began to ponder the question of how host females discriminate between a foreign egg and their own eggs,wondering how hosts 'know' which egg to remove.Results of one of the rst uncontrolled experiments were inappropriately interpreted to imply ejection was based on discordancy,with hosts simply ejecting the egg in the minority,or the 'odd-looking' egg.Controlled experiments eventually revealed that hosts rst learn the appearance of own their eggs and discriminate between them and any odd egg in their nest,regardless of which egg type is in the minority.Recent work has shown that discordancy may play a role in discrimination by males mated successively with females that lay polymorphic eggs.We examine the details of the early experiments,in light of recent advances in studies of egg recognition.An ability to recognize eggs also has been extended,implicitly,to include obligate brood parasites,as it underlies several hypotheses in explanation of the behavior of parasites toward their hosts.Egg recognition in parasites,however,has not been experimentally con rmed,nor has a mechanism been identi ed by which parasites could discriminate between their own eggs and the other eggs in a nest.We review hypotheses(parasite competition,egg removal and multiple parasitism,ma a,farming) that require the ability of obligate brood parasites to discriminate eggs at di erent levels and the potential mechanisms used by parasites to recognize their own eggs and suggest experiments to test for egg discrimination.An assessment of the egg recognition ability of parasites is germane to our understanding of how parasites counteract defenses of hosts.展开更多
The genus Diaporthe comprises pathogenic,endophytic and saprobic species with both temperate and tropical distributions.Cryptic diversification,phenotypic plasticity and extensive host associations have long complicat...The genus Diaporthe comprises pathogenic,endophytic and saprobic species with both temperate and tropical distributions.Cryptic diversification,phenotypic plasticity and extensive host associations have long complicated accurate identifications of species in this genus.The delimitation of the generic type species Diaporthe eres has been uncertain due to the lack of ex-type cultures.Species limits of D.eres and closely related species were evaluated using molecular phylogenetic analysis of eight genes including nuclear ribosomal internal transcribed spacer(ITS),partial sequences of actin(ACT),DNA-lyase(Apn2),translation elongation factor 1-α(EF1-α),beta-tubulin(TUB),calmodulin(CAL),60s ribosomal protein L37(FG1093)and histone-3(HIS).The occurrence of sequence heterogeneity of ITS within D.eres is observed,which complicates the analysis and may lead to overestimation of the species diversity.The strict criteria of Genealogical Concordance Phylogenetic Species Recognition(GCPSR)were applied to resolve species boundaries based on individual and combined analyses of other seven genes except the ITS.We accept nine distinct phylogenetic species including Diaporthe alleghaniensis,D.alnea,D.bicincta,D.celastrina,D.eres,D.helicis,D.neilliae,D.pulla and D.vaccinii.Epitypes are designated for D.alnea,D.bicincta,D.celastrina,D.eres,D.helicis and D.pulla.Modern descriptions and illustrations are provided for these species.Newly designed primers are introduced to amplify and sequence the Apn2(DNA-lyase)gene in Diaporthe.Based on phylogenetic informativeness profiles,EF1-α,Apn2 and HIS genes are recognised as the best markers for defining species in the D.eres complex.展开更多
Channel confluences are universally present in nature. They can be divided into two types： asymmetrical river confluences and symmetric river confluences. The latter is also called as the Y-shaped confluences. Most o...Channel confluences are universally present in nature. They can be divided into two types： asymmetrical river confluences and symmetric river confluences. The latter is also called as the Y-shaped confluences. Most of previous work has paid more attention to the asymmetrical river confluences, but few studies have been conducted on the Y-shaped confluences. In this article, the effects of bed discordance on the flow patterns at ＂Y＂ shaped open-channel confluences were studied by using a 3-D numerical simulation. It is proved that the model can undertake quantitative assessment of the flow at confluences. The results indicate that there are a lot of differences between the Y-shaped confluence and asymmetrical confluence. The discordant bed height plays an important role at the Y-shaped junction.展开更多
Quantum discord, one of the famous quantum correlations, has been recently generalized to multipartite systems by Radhakrishnan et al. Here we give analytical solutions of the quantum discord for a family of N-qubit q...Quantum discord, one of the famous quantum correlations, has been recently generalized to multipartite systems by Radhakrishnan et al. Here we give analytical solutions of the quantum discord for a family of N-qubit quantum states. For the bipartite system, we derive a zero quantum discord which will remain unchanged under the phase damping channel. For multiparitite systems, it is found that the quantum discord can be classified into three categories and the quantum discord for odd-partite systems can exhibit freezing under the phase damping channel, while the freezing does not exist in the even-partite systems.展开更多
基金supported by the National Natural Science Foundation of China (No.31970427 and 32270526 to WL)supported by the specific research fund of The Innovation Platform for Academicians of Hainan Province
文摘Most studies exploring abilities of hosts to detect brood parasitism are based on detecting colour and/or pattern differences among parasitic and host eggs or nestlings,while only few were focused on size differences.True recognition and recognition by discordancy are used to explain cognitive mechanisms of host egg recognition;however,only a few studies have found that hosts use recognition by discordancy.This study investigated:1)whether egg and nestling recognitions in the Crested Myna(Acridotheres cristatellus) are based on size cues;2)whether the egg cognitive mechanism is recognition by discordancy based on size cues;and 3) whether the longer the experiment time,the higher the egg recognition rate.Our results showed that the Crested Myna uses egg or nestling size as a recognition cue while the egg and nestling colour and patterning are not associated with egg or nestling rejection,thus the cognitive mechanism of egg recognition in the Crested Myna is recognition by discordancy based on egg size cues.Furthermore,there is a rejection delay in time of egg rejection behaviour of the Crested Myna.Therefore,we suggest that the periodicity of egg rejection experiments could be appropriately extended,especially for species with relatively low egg recognition ability.
基金supported by the National Natural Science Foundation of China(No.31970427 to WL and 32101242 to LM)by the Open Foundation of Hebei Key Laboratory of Wetland Ecology and Conservation(hklk201903 to LM)the Natural Science Foundation of Hebei Province of China(C2020101002 to LM)。
文摘Background:Nest parasitism by cuckoos(Cuculus spp.)results in enormous reproductive failure and forces hosts to evolve antiparasitic strategies,i.e.,recognition of own eggs and rejection of cuckoo eggs.There are often sexual conflicts between male and female individuals in the expression of antiparasitic behavior due to the differences in reproductive inputs and division of labor.Methods:By adding a foreign egg made of blue soft clay to the host nest during early incubation period in the field,and by removing several host eggs and adding experimental eggs to control the proportion of two egg types in the nest,we examined egg rejection ability,egg recognition mechanism and sexual difference in egg rejection of the Oriental Reed Warbler(Acrocephalus orientalis),one of the major hosts of Common Cuckoos(Cuculus canorus).Results:Our results indicated that Oriental Reed Warblers can recognize and reject nearly 100%(73/75)of the nonmimetic eggs made of blue soft clay,and they could reject foreign eggs with 100%accuracy,regardless of the ratio of experimental eggs and its own eggs in the nest.Furthermore,all cases of egg rejections recorded by videos were only carried out by females.Conclusions:Oriental Reed Warblers have a high egg recognition ability and show a true recognition mechanism.Only female warblers perform egg rejection,suggesting that the sex for host egg incubation seems to play an important role in the evolution of egg recognition mechanisms.
基金funded by the Education Department of Hainan Province(No.HnjgY,2022–12)the National Natural Science Foundation of China(No.32260127 to C.Y.)Doctoral Start-up Funds of China West Normal University(No.493002 to P.Y.).
文摘In the co-evolutionary system of avian brood parasitism,egg recognition and rejection are common and generally act as effective anti-parasitic adaptations by hosts.Accordingly,most studies have examined the role of parasite egg colors and markings in detection cues in hosts;however,studies focusing on the effects of egg size and quantity are relatively scarce and have mostly concentrated on the hosts of parasitic cowbirds.Here,we studied the egg recognition behaviors of a potential host of the Common Cuckoo(Cuculus canorus)—the Green-backed Tit(Parus monticolus),to determine:(1)whether the host uses the sizes of parasite eggs and/or the quantity contrast between parasite and host eggs as cues for recognition,(2)whether the host employs the template or discordant recognition mechanism for egg recognition,and(3)whether the size and quantity of parasite eggs affect the egg rejection modes of the hosts.The results indicate that Green-backed Tits did not use parasite egg size as a primary cue for egg recognition.We hypothesized that both visual and tactile detection might be involved in egg recognition by Green-backed Tits and suggest further studies after controlling for nest light conditions.Differences in egg quantity between parasites and hosts were not used as cues for egg recognition because the hosts employed the template mechanism rather than discordance to recognize parasite eggs.However,both the relative sizes and quantity of parasite and host eggs significantly affected the rejection modes of parasite eggs,and larger or more parasite eggs triggered higher probabilities of nest desertion in hosts.
基金funded chiefly by grants from the Natural Sciences and Engineering Research Council of Canada
文摘With the knowledge that cuckoos and cowbirds lay their eggs parasitically,and that some hosts eject parasitic eggs,ornithologists began to ponder the question of how host females discriminate between a foreign egg and their own eggs,wondering how hosts 'know' which egg to remove.Results of one of the rst uncontrolled experiments were inappropriately interpreted to imply ejection was based on discordancy,with hosts simply ejecting the egg in the minority,or the 'odd-looking' egg.Controlled experiments eventually revealed that hosts rst learn the appearance of own their eggs and discriminate between them and any odd egg in their nest,regardless of which egg type is in the minority.Recent work has shown that discordancy may play a role in discrimination by males mated successively with females that lay polymorphic eggs.We examine the details of the early experiments,in light of recent advances in studies of egg recognition.An ability to recognize eggs also has been extended,implicitly,to include obligate brood parasites,as it underlies several hypotheses in explanation of the behavior of parasites toward their hosts.Egg recognition in parasites,however,has not been experimentally con rmed,nor has a mechanism been identi ed by which parasites could discriminate between their own eggs and the other eggs in a nest.We review hypotheses(parasite competition,egg removal and multiple parasitism,ma a,farming) that require the ability of obligate brood parasites to discriminate eggs at di erent levels and the potential mechanisms used by parasites to recognize their own eggs and suggest experiments to test for egg discrimination.An assessment of the egg recognition ability of parasites is germane to our understanding of how parasites counteract defenses of hosts.
文摘The genus Diaporthe comprises pathogenic,endophytic and saprobic species with both temperate and tropical distributions.Cryptic diversification,phenotypic plasticity and extensive host associations have long complicated accurate identifications of species in this genus.The delimitation of the generic type species Diaporthe eres has been uncertain due to the lack of ex-type cultures.Species limits of D.eres and closely related species were evaluated using molecular phylogenetic analysis of eight genes including nuclear ribosomal internal transcribed spacer(ITS),partial sequences of actin(ACT),DNA-lyase(Apn2),translation elongation factor 1-α(EF1-α),beta-tubulin(TUB),calmodulin(CAL),60s ribosomal protein L37(FG1093)and histone-3(HIS).The occurrence of sequence heterogeneity of ITS within D.eres is observed,which complicates the analysis and may lead to overestimation of the species diversity.The strict criteria of Genealogical Concordance Phylogenetic Species Recognition(GCPSR)were applied to resolve species boundaries based on individual and combined analyses of other seven genes except the ITS.We accept nine distinct phylogenetic species including Diaporthe alleghaniensis,D.alnea,D.bicincta,D.celastrina,D.eres,D.helicis,D.neilliae,D.pulla and D.vaccinii.Epitypes are designated for D.alnea,D.bicincta,D.celastrina,D.eres,D.helicis and D.pulla.Modern descriptions and illustrations are provided for these species.Newly designed primers are introduced to amplify and sequence the Apn2(DNA-lyase)gene in Diaporthe.Based on phylogenetic informativeness profiles,EF1-α,Apn2 and HIS genes are recognised as the best markers for defining species in the D.eres complex.
基金supported by the National Natural Science Foundation of China(Grant No. 30490235).
文摘Channel confluences are universally present in nature. They can be divided into two types： asymmetrical river confluences and symmetric river confluences. The latter is also called as the Y-shaped confluences. Most of previous work has paid more attention to the asymmetrical river confluences, but few studies have been conducted on the Y-shaped confluences. In this article, the effects of bed discordance on the flow patterns at ＂Y＂ shaped open-channel confluences were studied by using a 3-D numerical simulation. It is proved that the model can undertake quantitative assessment of the flow at confluences. The results indicate that there are a lot of differences between the Y-shaped confluence and asymmetrical confluence. The discordant bed height plays an important role at the Y-shaped junction.
基金partially supported by the National Natural Science Foundation of China (Grant No. 11601338)。
文摘Quantum discord, one of the famous quantum correlations, has been recently generalized to multipartite systems by Radhakrishnan et al. Here we give analytical solutions of the quantum discord for a family of N-qubit quantum states. For the bipartite system, we derive a zero quantum discord which will remain unchanged under the phase damping channel. For multiparitite systems, it is found that the quantum discord can be classified into three categories and the quantum discord for odd-partite systems can exhibit freezing under the phase damping channel, while the freezing does not exist in the even-partite systems.
