Something in the wind: The influence of wind speed and direction on African lion movement behaviour

Olfaction is a key sense, enabling animals to locate forage, select mates, navigate their environment, and avoid predation. Wind is an important abiotic factor that modulates the strength of olfactory information detected by animals. In theory, when airflow is unidirectional, an animal can maximise the size of their olfactory search area and increase odour detection probability by moving crosswind. Given energetic costs inherent to activity and locomotion, behavioural search strategies that optimize the benefit-cost ratio should be advantageous. We tested whether African lions (Panthera leo) modify their movement directionality and distance according to wind speed and direction during hours of darkness when they are most likely to hunt mobile and elusive prey. We tracked 29 lions in southern Zimbabwe using GPS collars and deployed a weather station to collect detailed abiotic data. We found that when wind speeds increased lions were more likely to move crosswind. We also found that female lions, which tend to hunt more often than males, travelled farther when wind speeds were stronger. The results of our analysis suggest that lions adapt their movement behaviour according to wind speed and direction. We inferred that this was a behavioural decision to maximise the amount of olfactory information gained per unit of energy spent. Our findings not only offer one of the first detailed insights on large carnivore anemotaxis (movement direction relative to wind) but also make an important contribution towards understanding the influence of wind on predator ecology in general which remains understudied to date. Keywords: Panthera Leo, anemotaxis, wind, movement behaviour, olfaction

嗅觉是一类关键感官，可帮助动物定位觅食资源、选择配偶、辨识活动环境并规避捕食风险。风是一类重要的非生物因子，可调控动物所感知到的嗅觉信息强度。理论上，当气流呈单向流动时，动物可通过沿侧风向移动，最大化其嗅觉搜索范围并提升气味探测概率。考虑到活动与移动过程中固有的能量消耗，优化收益-成本比的行为搜索策略理应具备演化优势。本研究探究了非洲狮（Panthera leo）是否会在其最易捕猎灵活且难以追踪的猎物的暗夜时段，依据风速与风向调整其移动方向与移动距离。研究团队通过GPS项圈对津巴布韦南部的29头非洲狮进行了追踪，并布设气象站以收集高精度的非生物环境数据。结果显示，随着风速升高，非洲狮沿侧风向移动的概率显著提升。此外研究发现，雌性非洲狮的捕猎频率通常高于雄性，此类雌性个体在风速更高时的移动距离更远。分析结果表明，非洲狮的移动行为会依据风速与风向进行调整。研究团队据此推断，此类行为调整是为了最大化单位能量消耗所获取的嗅觉信息总量。本研究的发现不仅为大型食肉动物的趋风定向（anemotaxis，即相对于风向的移动方向）提供了首批详尽的研究洞察之一，同时也为理解风对捕食者生态学的普遍影响作出了重要贡献——此类议题迄今仍鲜有研究。关键词：非洲狮（Panthera leo）、趋风定向（anemotaxis）、风、移动行为、嗅觉