Surviving winter on the Qinghai-Tibetan Plateau: Pikas suppress energy demands and exploit yak feces to survive winter

	Surviving winter on the Qinghai-Tibetan Plateau: Pikas suppress energy demands and exploit yak feces to survive winter
	Speakman, John R.; Chi, Qingsheng; Oldakowski, Lukasz; Fu, Haibo; Fletcher, Quinn E.; Hambly, Catherine; Togo, Jacques; Liu, Xinyu; Piertney, Stuart B.; Wang, Xinghao
刊名	PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
	2021
卷号	118 期号:30
关键词	winter survival metabolic suppression thyroid axis
英文摘要	The Qinghai-Tibetan Plateau, with low precipitation, low oxygen partial pressure, and temperatures routinely dropping below -30 degrees C in winter, presents several physiological challenges to its fauna. Yet it is home to many endemic mammalian species, including the plateau pika (Ochotona curzoniae). How these small animals that are incapable of hibernation survive the winter is an enigma. Measurements of daily energy expenditure (DEE) using the doubly labeled water method show that pikas suppress their DEE during winter. At the same body weight, pikas in winter expend 29.7% less than in summer, despite ambient temperatures being approximately 25 degrees C lower. Combined with resting metabolic rates (RMRs), this gives them an exceptionally low metabolic scope in winter (DEE/RMRt = 1.60 +/- 0.30; RMRt is resting metabolic rate at thermoneutrality). Using implanted body temperature loggers and filming in the wild, we show that this is achieved by reducing body temperature and physical activity. Thyroid hormone (T3 and T4) measurements indicate this metabolic suppression is probably mediated via the thyroid axis. Winter activity was lower at sites where domestic yak (Bos grunniens) densities were higher. Pikas supplement their food intake at these sites by eating yak feces, demonstrated by direct observation, identification of yak DNA in pika stomach contents, and greater convergence in the yak/pika microbiotas in winter. This interspecific coprophagy allows pikas to thrive where yak are abundant and partially explains why pika densities are higher where domestic yak, their supposed direct competitors for food, are more abundant.
内容类型	期刊论文
源URL	[http://210.75.249.4/handle/363003/60766]
专题	西北高原生物研究所_中国科学院西北高原生物研究所
推荐引用方式 GB/T 7714	Speakman, John R.,Chi, Qingsheng,Oldakowski, Lukasz,et al. Surviving winter on the Qinghai-Tibetan Plateau: Pikas suppress energy demands and exploit yak feces to survive winter[J]. PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA,2021,118(30).
APA	Speakman, John R..,Chi, Qingsheng.,Oldakowski, Lukasz.,Fu, Haibo.,Fletcher, Quinn E..,...&Wang, Dehua.(2021).Surviving winter on the Qinghai-Tibetan Plateau: Pikas suppress energy demands and exploit yak feces to survive winter.PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA,118(30).
MLA	Speakman, John R.,et al."Surviving winter on the Qinghai-Tibetan Plateau: Pikas suppress energy demands and exploit yak feces to survive winter".PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA 118.30(2021).