Effects of climate change on the reproduction and offspring sex ratio of plateau pika (Ochotona curzoniae) on the Tibetan Plateau

Abstract Exploring animals’ responses to climate change will improve our understanding of the ecological consequences of such a phenomenon. As the “third pole” of the earth, the Tibetan Plateau is sensitive to climate change. To explore the effects of climate change on the reproduction of small mammals in an arid environment, we tested the reproduction of a native species, plateau pika ( Ochotona curzoniae ), from 2005 to 2009 in Dawu, which is located east of the Tibetan Plateau. The breeding season of this population maintained a stable onset date, but the length of breeding season varied from 53 to 84 days. The April temperature and spring precipitation positively affected the length of the breeding season. The offspring sex ratio was female biased except in 2009, whereas the ratio of recruits per reproductive female ( RRF ) ranged from 2.7 to 4.4. The April temperature and the normalized difference vegetation index (NDVI) in June positively affected the offspring sex ratio, whereas the precipitation in cold seasons and May NDVI positively affected the RRF . Therefore, increased temperature, precipitation, and NDVI may extend the length of the breeding season, increase the sex ratio, and produce more offspring recruits.