论文部分内容阅读
The outbreak of Plateau pika (Ochotona curzoniae) populations along with increased numbers of livestock has contributed to the degradation of the alpine meadow on the Tibetan Plateau.In April 2007,we undertook a single application of fertility control using cereal baits containing either no steroid (control site) ,quinestrol (0.005%) ,progesterone (0.005%) or a combination of the 2 steroids (EP-1; 0.005%) to plateau pika populations in the Guoluo District,south of Qinghai Province,China.In order to evaluate the effects of these treatments,we assessed the abundance of pikas and 3 bird species in the study sites (n=4) during August and September 2007 and 2008.Our results show that there was a significant reduction in pika abundance on the quinestrol-treated site compared with the control site in the second year (2008) after delivering the baits,while bird diversity and species richness did not decline significantly.The abundance of rufous-necked snowfinch and Humes groundpecker showed no significant differences between the 4 treatment sites.However abundance of white-rumped snowfinch was significantly lower in quinestrol treatment site compared to the control site.Reproduction of pikas on the quinestrol treatment site was reduced in 2007 and 2008,and their abundance was lower during 2008.In the absence of significant impacts on avian diversity,the application of quinestrol baits may represent a feasible approach to the management of this small mammal on Tibetan Plateau.