| In the spring-summer of2010and2011, we worked on the Passeriformes birds at the Wawushan Nature Reserve in Sichuan, China, including following aspects: competition and coexistence during the breeding season, nest-site selection, impact of human activities and so on. This thesis contains three parts, the first is about niche separation and coexistence between the Rufous-vented Tit (Parus rubidiventris) and Coal Tit (P. ater); the second is the nest-site selection of the Golden Bush Robin (Tarsiger chrysaeus); the third is to investigate the difference of nest-site selection between the tree nesting birds (such as the Aberrant Bush Warlber(Cettia flavolivaceus)) and the ground nesting birds (such as the Golden Bush Robin), and effects of human activities. The main results are as follows:(1) Being potential rivals, the Rufous-vented Tit and Coal Tit are occurred in the same habitat at the plateau of Wawushan in Sichuan, China. Their nest-sites are both located at arbor layer. For vertical distribution, the niche width of Coal Tit (5.237) is significantly higher than that of Rufous-vented Tit (2.792), however, there is no significant difference for horizontal distribution and active matrix, with the total value of niche overlap over0.7in three dimensions, but the two species of tits show preferences and focus on resource utilization of all these three dimensions. The parameters of most body’s measurements for these two tits are significantly different, except for the bill width, which may result from environmental adaptations. There is no significant difference for all the parameters of the nest-site selection of the two species, indicating that appropriate cavity nest sites might be their main competition factor. The population size of these two species may vary with their residence types. We suggest that the separation of spatial niche and food niche, appropriate population size and ratio might be the important factors for their coexistence.(2) The Principal Component Analysis shows that the main factors affecting the nest-site selection of the Golden Bush Robin include nest location, moss cover and arbor cover. The slopes suitable for nesting might be the basic conditions of their nest site selection. Human disturbance and the activities of small mammals might be important factors affecting nest site selection, distribution and quantity of their nests.(3) Human activities and different environmental factors made different effect on the birds with different nesting types. There is no significant difference for all11environment factors related to tree nesting birds, between the areas open or not open to the tourists, however, for ground nesting birds, there are significant differences for four factors, including the slope direction, slope degree, distance from nest to water resource and the height of nest from the ground. This suggested that there might be some differences for ground nesting birds in these two different areas. There is no significant difference for the breeding results and reproductive investment of the Golden Bush Robin in these two areas. We defined three areas (Mild, Moderate and Severe) concerning the intensity of human disturbance, The density of tree-nesting nests in these three areas are different, with Moderate disturbance area being highest, and the sequence is Moderate> Mild> Severe. For the density of ground nesting nests, it decreased with the increase of human activities, with the sequence of Mild> Moderate> Severe. So the birds with two types of nesting varied in their reaction of disturbance. We suggest that during the process of trade-off of pros and cons resulted from human activity, tree-nesting and ground nesting birds might adopt different strategy. |
PDF Full Text Request