White Clayton M, West George C
Department of Zoology, Brigham Young University, 84602, Provo, Utah, USA.
Institute of Arctic Biology, University of Alaska, 99701, Fairbanks, Alaska, USA.
Oecologia. 1977 Sep;27(3):227-238. doi: 10.1007/BF00347468.
Total lipids were extracted from 161 redpolls (Acanthis spp.) collected each month of the year from October 1962 to September 1963, in interior Alaska. A lipid index (Weight of ether extract x100/live body weight) was calculated for each sample. Lipids were also extracted from sections of pectoral muscle, livers and hearts representing each month.Body weight and lipid index were significantly positively correlated being highest in January and lowest in September. Total lipid content was significantly inversely correlated with air temperature; the high autumn and spring pre-migratory lipid peaks of migratory species were only weakly expressed in the redpolls. Liver lipid showed a significant annual variation being highest in December and lowest in August, while lipid from heart and pectoral muscle did not vary seasonally.Five birds were held in captivity during spring and summer at a constant temperature of 22°C. Food consumption was 5.1 g/day or 22.4 kcal. The caloric value of the most extensively utilized natural food, birch seed (Betula papyrifera), was determined (5.4-5.5 kcal/g dry wt). When esophageal diverticulae are full (2.0 g wet wt) of birch seeds, the resulting energy yield may sustain an individual for only a fraction of a 24 h winter day in contrast to other arctic herbivores (e.g. ptarmigan, Lagopus sp.) in which a full crop may suffice for the full 24 h period.
1962年10月至1963年9月期间，每月从阿拉斯加内陆收集161只普通朱雀（Acanthis spp.），并从中提取总脂质。计算每个样本的脂质指数（乙醚提取物重量×100/活体体重）。还从代表每个月的胸肌、肝脏和心脏切片中提取脂质。体重与脂质指数呈显著正相关，1月份最高，9月份最低。总脂质含量与气温呈显著负相关；迁徙物种秋季和春季迁徙前的脂质高峰在普通朱雀中表现较弱。肝脏脂质呈现出显著的年度变化，12月份最高，8月份最低，而心脏和胸肌中的脂质没有季节性变化。五只鸟在春季和夏季被圈养在22°C的恒温环境中。食物消耗量为5.1克/天或22.4千卡。测定了最广泛食用的天然食物桦树种子（Betula papyrifera）的热值（5.4 - 5.5千卡/克干重）。当食管憩室装满（2.0克湿重）桦树种子时，与其他北极食草动物（如雷鸟，Lagopus sp.）相比，由此产生的能量产量可能仅能维持个体在24小时冬季中的一小部分时间，在其他北极食草动物中，饱腹的嗉囊可能足以维持一整天。
