We present a three-part sensing system to measure the acquisition of foraging proficiency in wild tree squirrels. The first component is the eNut: a 3Dprinted enclosure in the size and shape of a large food item, such as a walnut. The eNut contains an inertial measurement unit (IMU), consisting of an accelerometer and a gyroscope, along with a capsule containing a food reward (e.g. chopped nuts), motivating the squirrel to manipulate the eNut to open the reward capsule. The second component is a radio-frequency identification (RFID) gate that can detect the presence of a known individual. The reader generates time-stamped labels for the analysis of simultaneous video recordings of the squirrel movements. Finally, the third component is a data collection pipeline, which aggregates the sensor data in a cloud backend server. The design process culminated in a fully-functional prototype system tested under three field conditions: two outdoor sites used for juvenile squirrel rehabilitation and a third site with free-ranging adult squirrels. The accuracy of the collected data is assessed by leveraging lab settings in which acceleration and rotation were checked against reference values produced by a testing infrastructure, custom-built for this application. Finally, we present an inventory of food item manipulation movements (rotation, shaking) that are identified and quantified with the eNut system. This system allows a level of granular analyses of foraging decisions that was not feasible with prior technology, which would have important translational value in paradigms of animal behavior and wildlife rehabilitation.

中文翻译：

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eNut：测量野生树松鼠觅食能力获得情况的传感系统


我们提出了一个由三部分组成的传感系统来测量野生树松鼠的觅食能力。第一个组件是 eNut：一个 3D 打印的外壳，其大小和形状与大型食品（例如核桃）相同。 eNut 包含一个由加速计和陀螺仪组成的惯性测量单元 (IMU)，以及一个包含食物奖励（例如切碎的坚果）的胶囊，激励松鼠操纵 eNut 打开奖励胶囊。第二个组件是射频识别（RFID）门，可以检测已知个体的存在。阅读器生成带时间戳的标签，用于分析松鼠运动的同步视频记录。最后，第三个组件是数据收集管道，它将传感器数据聚合到云后端服务器中。设计过程最终形成了一个在三个现场条件下进行测试的全功能原型系统：两个用于幼年松鼠康复的室外场地和第三个用于自由活动的成年松鼠的场地。所收集数据的准确性是通过利用实验室设置来评估的，其中根据为此应用程序定制的测试基础设施生成的参考值检查加速度和旋转。最后，我们提出了使用 eNut 系统识别和量化的食品操纵运动（旋转、摇动）的清单。该系统可以对觅食决策进行一定程度的精细分析，这在现有技术中是不可行的，这在动物行为和野生动物康复范例中具有重要的转化价值。