Influence of the habitat change for birds on community structure

In order to study the influence of habitat change on the community structure of birds, the species and individual numbers in the lakeside developmental land of Thousand-Island Lake have been recorded since January 2009 till December 2010, A fixed sample line was set up in the studied area, and the primary data was obtained about twice a month. In 2009, 1814 individuals were observed belonging to 12 orders, 31 families and 78 species, among which 4 species (Milvus lineatus, Haliastur Indus, Circus cyaneus and Glaucidium cuculoides) are the rank II national key protected species. In 2010, 872 individuals were recorded belonging to 12 orders, 33 families and 77 species, among which 2 species (Milvus lineatus and Glaucidium cuculoides) are the rank II national key protected ones. The total individual number of birds reduced 51.9%. Concerning the species, although the total species number decreased rarely after the habitat change, 23 species fled away and 22 species entered indicating the population similarity index value of 0.55. Among the top 10 species with large number of individuals, 5 species (Spizixos semitorques, Pycnonotus xanthorrhous, Paradoxornis webbianus, Passer montanus and Carduelis sinica) were overlapped indicating the similarity index value of 0.5. Comparison of the data of the corresponding months between two years, the highest similarity (index value>0.6) was from January to February; and the lowest (index value<0.3) from March to May. From June to December, the similarity index value was rebounded to 0.35–0.52 might due to the food tempt. Among the 55 overlapped species, 17 species (Tachybaptus ruficollis, Egretta garzetta, Phasianus colchicus, Streptopelia orientalis, Hirundo rustica, Hirundo daurica, Motacilla alba, Spizixos semitorques, Pycnonotus xanthorrhous, Pycnonotus sinensis, Urocissa erythrorhyncha, Paradoxornis webbianus, Prinia inornata, Passer rutilans, Passer montanus, Lonchura punctulata and Carduelis sinica) showed significant differences in individual number between the unchanged habitat and the changed habitat, including 2 species of water birds and 15 species of forest birds, which indicate these two types of birds were more affected than the others. In other words, the birds living close to the human crowds suffered bigger effect than the birds living away from the crowds. This is considered that the vocals, vehicle and machinery noises, and artificial constructions contributing to habitat change might be one of the main factors. All these analysis suggest the great influence of habitat change caused by human on the bird community structure. The higher diversity, richness and evenness index values in 2010 than in 2009 suggests that environmental modification led to a certain degree of habitat amelioration. Therefore, human being can improve environment by making the plant community structure complexity to increase the habitat heterogeneity, and consequently enhancing the diversity of bird community, as long as the habitat is not fragmented.