Data from: On the scaling of activity in tropical forest mammals

Activity range – the amount of time spent active per day – is a fundamental aspect contributing to the optimization process by which animals achieve energetic balance. Based on their size and the nature of their diet, theoretical expectations are that larger carnivores need more time active to fulfil their energetic needs than do smaller ones and also more time active than similar-sized non-carnivores. Despite the relationship between daily activity, individual range and energy acquisition, large-scale relationships between activity range and body mass among wild mammals have never been properly addressed. This study aimed to understand the scaling of activity range with body mass, while controlling for phylogeny and diet. We built simple empirical predictions for the scaling of activity range with body mass for mammals of different trophic guilds and used a phylogenetically controlled mixed model to test these predictions using activity records of 249 mammal populations (128 species) in 19 tropical forests (in 15 countries) obtained using camera traps. Our scaling model predicted a steeper scaling of activity range in carnivores (0.21) with higher levels of activity (higher intercept), and near-zero scaling in herbivores (0.04). Empirical data showed that activity ranges scaled positively with body mass for carnivores (0.061), which also had higher intercept value, but not for herbivores, omnivores and insectivores, in general, corresponding with the predictions. Despite the many factors that shape animal activity at local scales, we found a general pattern showing that large carnivores need more time active in a day to meet their energetic demands.

日活动时长（Activity range，即每日活跃的总时长）是助力动物实现能量平衡的优化过程中的核心构成要素。基于体型与食性特征，学界理论推测：大体型食肉动物为满足能量需求所需的每日活跃时长，多于小型食肉动物，同时也多于体型相近的非食肉动物。尽管已有研究关注日活动时长、个体活动范围与能量获取之间的关联，但野生哺乳动物的日活动时长与体重间的宏观尺度关联迄今尚未得到充分探讨。本研究旨在探究日活动时长与体重的异速缩放（scaling）关系，并控制系统发育与食性的干扰效应。我们针对不同营养类群（trophic guilds）的哺乳动物，构建了日活动时长与体重异速缩放关系的简易经验预测模型，并采用系统发育校正混合模型（phylogenetically controlled mixed model），借助15个国家19处热带森林中通过红外相机陷阱（camera traps）获取的249个哺乳动物种群（涵盖128个物种）的活动记录，对上述预测进行了验证。我们的异速缩放模型预测，食肉动物的日活动时长异速缩放斜率更高（0.21），且基础活动水平更高（截距更大）；而植食动物的异速缩放斜率近乎为零（0.04）。实证数据显示，食肉动物的日活动时长与体重呈正相关异速缩放（斜率为0.061），且截距值更高；但植食动物、杂食动物与食虫动物并未呈现该趋势，整体与预测结果相符。尽管诸多因素会在局地尺度上影响动物的活动水平，但本研究仍发现了一项通用规律：大体型食肉动物每日需要更长的活跃时长，以满足自身的能量需求。