Demographic data show many populations of Rocky Mountain (Cervus elaphus nelsoni) and Roosevelt (Cervus elaphus roosevelti) elk have been declining over the last few decades. Recent work suggests that forage quality and associated animal nutritional condition, particularly in late summer and early autumn, influence reproduction and survival in elk. Therefore, we estimated seasonal nutritional condition of 861 female elk in 2,114 capture events from 21 herds in Washington, Oregon, Wyoming, Colorado, and South Dakota from 1998 to 2007. We estimated ingesta‐free body fat and body mass, and determined age, pregnancy status, and lactation status. We obtained estimates for most herds in both late winter–early spring (late Feb–early Apr) and in autumn (Nov–early Dec) to identify changes in nutritional condition of individuals across seasons.

中文翻译：

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麋鹿营养状况和繁殖的区域和季节模式

人口统计数据显示落基山（Cervus elaphus nelsoni）和罗斯福（Cervus elaphus roosevelti）的许多种群）麋鹿在过去的几十年中一直在下降。最近的研究表明，饲草质量和相关的动物营养状况，特别是在夏末和初秋，会影响麋鹿的繁殖和生存。因此，我们估算了1998年至2007年华盛顿，俄勒冈州，怀俄明州，科罗拉多州和南达科他州的21个牧群的2114次捕获事件中的861只雌性麋鹿的季节性营养状况。我们估算了无摄取的体脂和体重，并确定了年龄，怀孕状态和哺乳状态。我们获得了冬末至春季（2月下旬至4月初）和秋季（11月至12月上旬）大部分畜群的估计数，以确定各个季节个体的营养状况变化。