Participants in mixed-species bird flocks(MSFs)have been shown to associate with species that are similar in body size,diet,and evolutionary history,suggesting that facilitation structures these assemblages.In additio...Participants in mixed-species bird flocks(MSFs)have been shown to associate with species that are similar in body size,diet,and evolutionary history,suggesting that facilitation structures these assemblages.In addition,several studies have suggested that species in MsFs resemble each other in their plumage,but this question has not been systematically investigated for any MsF system.During the nonbreeding season of 2020 and 2021,we sampled 585 MSFs on 14 transects in 2 habitats of Tongbiguang Nature Reserve in western Yunnan Province,China.We performed social network analysis and the Multiple Regression Quadratic Assignment Procedure to evaluate the effect of 4 species traits(body size,overall plumage color,distinctive plumage patterns,and diet)and evolutionary history on species association strength at the whole-MSF and within-MSF levels.All 41 significant relationships showed that species with stronger associations were more similar in their various traits.Body size had the strongest effect on association strength,followed by phylogeny,plumage patterns,and plumage color;diet had the weakest effect.Our results are consistent with the hypotheses that the benefits of associating with phenotypically similar species outweigh the potential costs of interspecific competition,and that trait matching can occur in plumage characteristics,albeit more weakly than in other traits.Several explanations exist as to why similarities in plumage may occur in MSFs,including that they could reduce predators'ability to target phenotypically"odd"individuals.Whether trait matching in plumage occurs through assortative processes in ecological time or is influenced by co-evolution requires furtherstudy.展开更多
The human central nervous system（CNS）has a markedly poor capacity for regenerating its axons following injury.This appears to be due to two main causes：1）a developmentally regulated decline in regenerative capacit...The human central nervous system（CNS）has a markedly poor capacity for regenerating its axons following injury.This appears to be due to two main causes：1）a developmentally regulated decline in regenerative capacity within mature CNS neurons,and 2）the presence of biological components that constitute barriers to axon regeneration（e.g.,growth-inhibitory molecules）.展开更多
基金funded by postdoctoral funding to LZ from Guangxi University(A3360051014,A3360051010)from the Guangxi Key Laboratory of Forest Ecology and Conservation(AE33600102).
文摘Participants in mixed-species bird flocks(MSFs)have been shown to associate with species that are similar in body size,diet,and evolutionary history,suggesting that facilitation structures these assemblages.In addition,several studies have suggested that species in MsFs resemble each other in their plumage,but this question has not been systematically investigated for any MsF system.During the nonbreeding season of 2020 and 2021,we sampled 585 MSFs on 14 transects in 2 habitats of Tongbiguang Nature Reserve in western Yunnan Province,China.We performed social network analysis and the Multiple Regression Quadratic Assignment Procedure to evaluate the effect of 4 species traits(body size,overall plumage color,distinctive plumage patterns,and diet)and evolutionary history on species association strength at the whole-MSF and within-MSF levels.All 41 significant relationships showed that species with stronger associations were more similar in their various traits.Body size had the strongest effect on association strength,followed by phylogeny,plumage patterns,and plumage color;diet had the weakest effect.Our results are consistent with the hypotheses that the benefits of associating with phenotypically similar species outweigh the potential costs of interspecific competition,and that trait matching can occur in plumage characteristics,albeit more weakly than in other traits.Several explanations exist as to why similarities in plumage may occur in MSFs,including that they could reduce predators'ability to target phenotypically"odd"individuals.Whether trait matching in plumage occurs through assortative processes in ecological time or is influenced by co-evolution requires furtherstudy.
文摘The human central nervous system（CNS）has a markedly poor capacity for regenerating its axons following injury.This appears to be due to two main causes：1）a developmentally regulated decline in regenerative capacity within mature CNS neurons,and 2）the presence of biological components that constitute barriers to axon regeneration（e.g.,growth-inhibitory molecules）.
