Research On Bird Feeding Guilds In Tiantong National Forest Park, Zhejiang Province

In recent years,the guild theory is increasingly applied to the study of bird ecology.The bird guilds can be divided from different angles which will contribute to understand the use of internal resources within the bird community and the interspecific coexistence relationship.And it also reflects the growth of regional forest system development from the side.The author collected bird foraging and habitat data in the study area of Tiantong National Forest Park during October 2015 and September 2016.The classification of bird communities in different seasons can be analyzed by cluster analysis according to the bird's use of food resources in different ways of foraging and different heights,locations,and substrates.In order to understand the habitat selection and coexistence mechanism in the same guild of birds,we analyze the differences in the utilization of habitat types among same bird guild in different seasons from the angle of ecological niche.The results are as follows:1.The Composition of the Birds Fauna in Tiantong National Forest ParkTotally 113 species of birds are recorded during the survey period.Those birds belong to 13 orders and 39 families.Most of them are Passeriformes,including 24 families and 74 species,which account for 65.5%of the total number of bird species.Non-passeriformes birds includes Strigiformes,Falconiformes,Ciconiiformes,Podicipediformes,Coraciiformes,Piciformes and so on.The overall bird species has increased from previous years.There are significant differences in bird diversity throughout a year(p<0.01).The highest value appeared in December and in smmer it presents a lower level.The annual richness shows a significant difference(p<0.01)and also reached the maximum peak in December.The degree of bird is highly significant(p<0.01).Species are at least level(22 species)in July and gradually rise up and reach the maximum(61 species)in October.At this time a large number of migratory birds will stay in this place and share the food and habitat resources with the local resident birds,by which they can reserve energy for continuing migration and foraging.2.Seasonal changes in the structure of bird foraging guilds in Tiantong National Forest ParkAccording to the feeding situation in different seasons,the birds can be divided in to different guilds.They have 6 guilds in spring,a ground feeding guild,a shrub feeding guild,a canopy feeding guild,a air feeding guild,a water feeding guild and a trunk feeding guild.The other seasons only have 5 feeding groups because of the lack of trunk feeding guild.The composition of birds within the guilds has changed greatly in different seasons.And the same bird species in different seasons will belong to different feeding guilds.Such as the Daurian Redstart,in the spring they belong to the ground feeding guild,and they will become shrub feeding in winter.David's Fulvetta are belong to the canopy feeding guild In fall and other seasons in the shrub feeding guild.The clustering result shows the level of polymerization is lower between some birds(d<3.0),which indicating that they have a greater overlap in the way of feeding and there may be a fierce competition between them.3.Coexistence within the Same Guild in Different SeasonsUnivariate analysis of variance shows that there are some differences or significant differences in the four feeding dimensions of a part of bird feeding guilds in different seasons.The study of the utilization of habitat resources by bird communities revealed that the most popular forests is broadleaf forests no matter in which season(32 species,25 species,42 species,30 species).And the number of birds is not equal in different habitat and it will changes as the richness of food resources changes in different season.The comparative analysis of the ecological niche breadth and overlaps of different bird feeding guilds in different seasons reveals that the similar species in feeding selection shows a large difference in seasonal variation.The different birds in the same guild maintain a stable coexistence through the expansion and reduction of ecological niche.Spearman correlation analysis of foraging niche and habitat types niche within the guilds of bird shows that there was no significant correlation between the seasonal variation of the feeding dimension and habitat types niche with the immigration and emigration of migratory birds.The result indicates that migratory birds have had a significant change in the community structure and internal composition of the bird feeding guild,But the migratory birds did not have a greater impact on the foraging of the resident birds.