Study On Effects Of Occupancy Of The Plateau Pika(Ochotona Curzoniae) On The Distribution Of Two Alpine Passerine Species

As a small dominant mammal and ecosystem engineer in Qinghai-Tibetan grassland ecosystems,the plateau pika(Ochotona curzoniae)is ecologically important in maintaining species diversity in alpine grassland ecosystems.Its moderate disturbance and excavation activities not only enhance vegetation diversity and abundance in alpine grassland ecosystems,but excavation produces burrows that also provide habitat for a variety of burrowing animals on the plateau.At present,There is a paucity of research and information on the relationship between plateau pika and cavity-nesting plateau birds.In particular,there is a lack of research on the effects of plateau pika occupancy on the distribution of alpine passerine species under the action of different environmental factors and different land-uses.For this reason,the study was conducted from September to October 2021 in the Zhegu steppe,with 40 sample lines,40 sample plots,200 sample squares and 1 km between sample plots.The data were recorded for different land-use type,different environmental factors,as well as for the number of plateau pika populations,the number of burrows,and the absence or occurrence(0/1)of two passerine species,the white-rumped snowfinch(Pyrgilauda taczanowskii)and rufous-necked snowfinch(Montifringilla ruficollis).The correlation between plateau pika occupancy and the distribution of two passerine species,the white-rumped snowfinch and the rufous-necked snowfinch,under different land-uses and environmental factors in the Zhegu steppe was investigated using a single-season occupancy model combined with the sample line method.The purpose of this study is to illustrate how the distribution of two alpine passerine species,the white-rumped snowfinch and the rufous-necked snowfinch,in the Zhegu steppe,and to provide a theoretical basis for the study of the interactions between other plateau birds or other animals under different environmental factors and different land-uses,and thus to provide information for the study of species distribution and species diversity in Plateau grassland ecosystems.The main results are as follows:1.There were two optimal models supporting the data in the single-season occupancy model for plateau pika occupancy and white-rumped snowfinch distribution under different land-uses;namely:Model 1 white-rumped snowfinch site occupancy rate was negatively correlated with different land-uses such as grazing-sand mining,grazing-power pole,grazing-viewing platform,grazing-housing and grazing-crop;and there was a positive correlation between white-rumped Snowfinch site occupancy rate and the number of populations and burrows of plateau pika under these five different land-uses.Model 2white-rumped snowfinch site occupancy rate was negatively correlated with different land-uses such as grazing-sand mining,grazing-electric pole,grazing-viewing platform,grazing-housing and grazing-crop;and there was a positive correlation between white-rumped snowfinch site occupancy rate and the number of populations and burrows of plateau pika under these five different land-uses.2.There were two optimal models supporting the data in the singleseason occupancy model for plateau pika occupancy and rufous-necked snowfinch under distribution different land-uses;namely: model 1rufous-necked snowfinch site occupancy rate was negatively correlated with different land-uses such as grazing-sand mining,grazing-electric pole,grazing-viewing platform and grazing-housing,but positively correlated with land-use grazing-crop;and under these different land-uses,rufous-necked snowfinch site occupancy rate was positively correlated with the number of plateau pika populations;and negatively correlated with the number of burrows.Model 2 rufous-necked snowfinch site occupancy rate was negatively correlated with different land-uses such as grazing-sand mining,grazing-electric pole,grazing-viewing platform and grazing-housing,but positively correlated with land-use grazing-crop,and under these different land-uses,rufous-necked snowfinch site occupancy rate was positively correlated with the number of plateau pika populations;and negatively correlated with the number of burrows.3.There were eight optimal models supporting the data in the single-season occupancy model for plateau pika occupancy and white-rumped snowfinch distribution under different environmental factors,showed that the white-rumped snowfinch was positively correlated with two levels of anthropogenic disturbance,moderate and light,distance from anthropogenic disturbance,elevation,grassland habitat,distance from water sources and distance from roads,and negatively correlated with vegetation cover,Yin and yang slope orientation and scrub habitat.Meanwhile,the white-rumped snowfinche site occupancy rate was positively correlated with the number of plateau pika populations and the number of burrows under the combined effect of these different environmental factors.4.There were nine optimal models supporting the data in the single-season occupancy model for plateau pika occupancy and rufous-necked snowfinch distribution under different environmental factors,showed that the rufous-necked snowfinch site occupancy rate was positively correlated with two levels of anthropogenic disturbance,moderate and light,distance from anthropogenic disturbance,distance from water,grassland habitat,slope orientation on Yin and Yang slopes and slope gradients of 5°,10°,20°,21°,22° and 30°.Meanwhile,the rufous-necked snowfinch site occupancy rate was positively correlated with the number of plateau pika populations and negatively correlated with the number of plateau pika burrows under the combined effect of these different environmental factors.Based on the above research results,it has been effectively demonstrated that the distribution and habitat selection of the white-rumped snowfinch and rufous-necked snowfinch are closely related to the population and burrows of the plateau pika,both under different land-uses and under different environmental factors.The correlation between the distribution of the plateau pika and two alpine passerine species,the white-rumped snowfinch and the rufous-necked snowfinch,can provide a theoretical basis for future studies of the plateau pika and other plateau ground-nesting birds.