Persistence hunting has been suggested to be a key strategy for meat acquisition in Homo erectus. However, prolonged locomotion in hot conditions is associated with considerable water losses due to sweating. Consequently, dehydration has been proposed to be a critical limiting factor, effectively curtailing the usefulness of persistence hunting prior to the invention of water containers. In this study, we aimed to determine the extent to which dehydration limited persistence hunting in H. erectus. We simulated ambient conditions and spatiotemporal characteristics of nine previously reported persistence hunts in the Kalahari. We used a newly developed and validated heat exchange model to estimate the water loss in H. erectus and a recent Kalahari hunter. Water loss equivalent to 10% of the hunter's body mass was considered the physiological limit of a hunt with no drinking. Our criterion for ruling dehydration out of being a limit for persistence hunting was the ability to hunt without drinking for at least 5 h, as this was the longest duration reported for a successful persistence hunt of large prey. Our results showed that H. erectus would reach the dehydration limit in 5.5-5.7 h of persistence hunting at the reported Kalahari conditions, which we argue represent a conservative model also for Early Pleistocene East Africa. Maximum hunt duration without drinking was negatively related to the relative body surface area of the hunter. Moreover, H. erectus would be able to persistence hunt over 5 h without drinking despite possible deviations from modern-like heat dissipation capacity, aerobic capacity, and locomotor economy. We conclude that H. erectus could persistence hunt large prey without the need to carry water.

中文翻译：

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直立人的脱水和持续性狩猎。

有人提出，坚持狩猎是直立人获取肉类的关键策略。但是，在炎热的条件下长时间运动会因出汗而造成大量的水分流失。因此，已经提出脱水是关键的限制因素，在发明水容器之前有效地减少了持久性狩猎的作用。在这项研究中，我们旨在确定脱水限制了直立H.持续性狩猎的程度。我们模拟了卡拉哈里的9个先前报道的持久性狩猎的环境条件和时空特征。我们使用了一个新开发和验证的热交换模型来估计直立人和最近的卡拉哈里猎人的水分流失。失水量相当于猎人的10％的体重被认为是不饮酒狩猎的生理极限。我们将脱水排除为持久性狩猎的限制的标准是不喝酒至少5个小时的狩猎能力，因为这是成功进行大型猎物持久性狩猎的最长持续时间。我们的结果表明，在报道的卡拉哈里条件下，直立嗜血杆菌在持续狩猎5.5-5.7小时内将达到脱水极限，我们认为这代表了东非早期更新世的一个保守模型。不饮酒的最大狩猎持续时间与猎人的相对身体表面积呈负相关。此外，尽管可能与现代的散热能力，有氧能力和运动经济性有所偏差，但直立嗜血杆菌仍能够坚持饮酒5小时以上，而无需饮酒。