| According to the principle of competitive exclusion in ecology,if different species with sympatric distribution and ecological similarity can coexist for a long time,they need to be differentiated in multi-dimensional ecological niches(time,space,diet,etc.).The research on niche differentiation of sympatric breeding birds can clarify the ecological needs of birds and their differentiation in multi-dimensional ecological niches,and provide scientific basis for bird protection and habitat management.In this study,artificial nesting boxes were hung in Zuojia Nature Reserve in Jilin Province from March to July in 2021 and 2022 to attract Japanese tit(Parus minor)and Yellow-rumped flycatcher(Ficedula zanthopygia).Fecal samples were collected at the same time of breeding period to analyze the diet of the two birds.The site selection characteristics were analyzed by measuring the height from nest to ground,tree diameter at breast height and percentage of the nest covered.Reproductive parameters of the two species such as first egg laying date,the incubation date and the hatching date were collected to analyze the differences in reproductive time.Based on those analyses,I investigated the niches overlap and differentiation between two bird species.The main results are as follows:1.Japanese tit and Yellow-rumped flycatcher mainly prey on arthropod of Lepidoptera(the relative read abundance was 34.6%and 56.4%,respectively),Araneae(32.2%and 7%)and Diptera(6%and 12.7%),including 52 species of 36 families.There were significant differences between the two species in the consumption of Lepidoptera(Kruskal-Wallis test,χ~2=4.223,P=0.04),and in the utilization of Coleoptera(Kruskal-Wallis test,χ~2=7.818,P=0.005),Diptera(Kruskal-Wallis test,χ~2=7.168,P=0.007)and Elateridae(Chi-square test,χ~2=9.806,P=0.002)There was a significant significant difference in Coleoptera consumption(Chi-square test,χ~2=4.013,P=0.045)between male and female in Japanese tit,and the consumption frequency of males was higher than that of females(84.2%,the percent frequency of occurrence)was higher than that of females(56.7%).The niche overlap of Japanese tit and Yellow-rumped flycatcher was higher,and the width of diet niche of Yellow-rumped flycatcher was higher than Japanese tit,indicating that the food resources of Yellow-rumped flycatcher were more diverse during the breeding period.2.Nest cover(Mann-Whitney U test,P=0.003),density of undergrowth shrubs(P<0.001)and canopy cover(P=0.019)in Yellow-rumped flycatcher were greater than that of Japanese tit,indicating that Yellow-rumped flycatcher has a higher requirement for nest site concealability.The nest niche width of the Yellow-rumped flycatcher is larger than that of Japanese tit,suggesting that the Yellow-rumped flycatcher tends to be a generalised species in nest selection.The nests of the two species overlapped greatly,suggesting that there might be a more intense competition.3.In terms of breeding time,there were significant differences in the length of egg-laying periods between Japanese tit and Yellow-rumped flycatcher(GLMM,P=0.03).There were no significant differences in first egg-laying date,the incubation date,the hatching date and the length of incubation periods,but the peak of egg-laying and incubation date of Yellow-rumped flycatcher was about one month later than that of Japanese tit.This difference in breeding timing can effectively stagger the peak of food demand of nestlings and reproductive energy demand of parent birds,which is conducive to coexist of sympatric species.In conclusion,there were niche differentiation in diet,nest site selection and breeding time niche for sympatric breeding P.minor and F.zanthopygia,which may reduce their interspecific competition and be helpful their stable coexistence.The study would deepen our understanding of the interspecific relationship and interaction between birds and their living environment,and provide some scientific basis for the habitat management and protection of sympatric birds. |
