Among tetrapods, grasping is an essential function involved in many vital behaviours. The selective pressures that led to this function were widely investigated in species with prehensile hands and feet. Previous studies namely highlighted a strong effect of item properties but also of the species habitat on manual grasping behaviour. African savannah elephants (Loxodonta africana) are known to display various prehensile abilities and use their trunk in a large diversity of habitats. Composed of muscles and without a rigid structure, the trunk is a muscular hydrostat with great freedom of movement. This multitasking organ is particularly recruited for grasping food items while foraging. Yet, the diet of African savannah elephants varies widely between groups living in different habitats. Moreover, they have tusks alongside the trunk which can assist in grasping behaviours, and their tusk morphologies are known to vary considerably between groups. Therefore, in this study, we investigate the food grasping techniques used by the trunk of two elephant groups that live in different habitats: an arid study site in Etosha National Park in Namibia, and an area with consistent water presence in Kruger National Park in South Africa. We characterised the tusks profiles and compared the grasping techniques and their frequencies of use for different foods. Our results show differences in food‐grasping techniques between the two groups. These differences are related to the food item property and tusk profile discrepancies highlighted between the two groups. We suggest that habitat heterogeneity, particularly aridity gaps, may induce these differences. This may reveal an optimisation of grasping types depending on habitat, food size and accessibility, as well as tusk profiles.

中文翻译：

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栖息地和象牙对非洲草原象象鼻抓取技术的影响

在四足动物中，抓握是许多重要行为的重要功能。导致这种功能的选择压力在手脚可抓握的物种中得到了广泛的研究。先前的研究强调了物品属性以及物种栖息地对手动抓取行为的强烈影响。非洲草原象（非洲象牙虫）众所周知，它们表现出各种抓握能力，并在各种各样的栖息地中使用它们的树干。躯干由肌肉组成，没有刚性结构，是一个肌肉发达的静水器，具有很大的运动自由度。这种多任务器官特别适合在觅食时抓取食物。然而，生活在不同栖息地的非洲草原象的饮食差异很大。此外，它们的躯干旁边有长牙，可以帮助抓握行为，而且众所周知，它们的长牙形态在不同群体之间有很大差异。因此，在这项研究中，我们调查了生活在不同栖息地的两个象群使用的鼻子抓取食物的技术：纳米比亚埃托沙国家公园的一个干旱研究地点，以及南部克鲁格国家公园的一个有持续水存在的区域。非洲。我们描述了象牙的轮廓，并比较了不同食物的抓取技术及其使用频率。我们的结果显示两组之间的食物抓取技术存在差异。这些差异与两组之间突出的食品特性和象牙轮廓差异有关。我们认为栖息地的异质性，特别是干旱差距，可能会导致这些差异。这可能揭示了根据栖息地、食物大小和可及性以及象牙轮廓的抓取类型的优化。