Seasonal acclimatization of metabolism in Eurasian tree sparrows (Passer montanus

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• 作者：Wei-Hong Zheng ; Ming Li ; Jin-Song Liu ; Shu-Li Shao
• 关键词：Basal metabolic rate (BMR) ; Thermoregulation ; Eurasian tree sparrow (Passer montanus)
• 刊名：Comparative Biochemistry and Physiology - Part A: Molecular & Integrative Physiology
• 出版年：2008
• 出版时间：December 2008
• 年：2008
• 卷：151
• 期：4
• 页码：519-525
• 全文大小：519 K

文摘

Acclimatization to winter conditions is an essential prerequisite for survival of small passerines of the northern temperate zone. Changes in photoperiod, ambient temperature and food availability trigger seasonal acclimatization in physiology and behavior of many birds. In the present study, seasonal adjustments in several physiological, hormonal, and biochemical markers were examined in wild-captured Eurasian tree sparrows (Passer montanus) from the Heilongjiang Province in China. In winter sparrows had higher body mass and basal metabolic rate (BMR). Consistently, the dry mass of liver, heart, gizzard, small intestine, large intestine and total digestive tract were higher in winter than in that in summer. The contents of mitochondrial protein in liver, and state-4 respiration and cytochrome c oxidase (COX) activity in liver and muscle increased significantly in winter. Circulating level of serum triiodothyronine (T₃) was significantly higher in winter than in summer. Together, these data suggest that tree sparrows mainly coped with cold by enhancing thermogenic capacities through increased organ masses and heightened activity of respiratory enzymes activities. The results support the view that prominent winter increases in BMR are manifestations of winter acclimatization in tree sparrows and that seasonal variation in metabolism in sparrows is similar to that in other small temperate-wintering birds.