Understanding nutritional condition of animals can provide insight into underlying drivers of population dynamics. To estimate nutritional condition, indices require capture or mortality of animals to obtain measurements of body fat. Advances in technology provide an opportunity to acquire estimates of nutritional condition in a noninvasive way if ocular estimates can be validated. We developed and evaluated a noninvasive, visual index of nutritional condition for mule deer (Odocoileus hemionus) intended to be applied to camera‐trap images or videos. Our index was based on the visibility of 4 skeletal regions that are covered in varying amounts of subcutaneous fat depending upon the nutritional condition of the animal. We compared the visual index of nutritional condition to estimates of percent ingesta‐free body fat (IFBFat) obtained from ultrasonography and physical palpation of captured mule deer (n = 89) in western Wyoming, USA, in December 2015, March 2016, and November 2018. Our visual index of nutritional condition related positively to IFBFat (r² = 0.41). Although further refinement may be warranted to increase predictive power of visual estimates, use of visual approaches to estimate nutritional condition can enhance knowledge that can be gained with a minimal budget, or where more invasive approaches are not possible. © 2020 The Wildlife Society.

中文翻译：

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使用摄影指数评估M鹿的营养状况

了解动物的营养状况可以深入了解种群动态的潜在驱动因素。为了估计营养状况，指数需要捕获动物或杀死动物以获得体内脂肪的测量值。如果可以对眼部估计进行验证，那么技术的进步提供了一种以无创方式获得营养状况估计的机会。我们开发并评估了invasive鹿（Odocoileus hemionus）营养状况的非侵入性视觉指标），旨在应用于相机捕获的图像或视频。我们的指数是根据动物的营养状况，在4个骨骼区域的可见性得出的，这些骨骼区域被不同数量的皮下脂肪覆盖。我们将营养状况的视觉指标与 2015年12月，2016年3月和11月在美国西部怀俄明州通过超声检查和物理触诊捕获的m鹿（n = 89）获得的无摄食体脂肪百分比（IFBFat）进行了比较2018.我们的营养状况视觉指数与IFBFat（r ² = 0.41）。尽管可能需要进一步完善以提高视觉估计的预测能力，但是使用视觉方法估计营养状况可以增加以最小的预算获得的知识，或者在不可能采用更多侵入性方法的情况下。©2020野生动物协会。