Desert ants compensate for navigation uncertainty
Desert ants compensate for navigation uncertainty
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DOI：
10.1242/jeb.01905
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发表时间：
2005-11-01
影响因子：
2.8
通讯作者：
Wehner, R
中科院分区：
文献类型：
--
作者：
Wolf, H;Wehner, R
在觅食过程中，沙漠蚂蚁不仅依赖于它们经过充分研究的路径整合系统，当它们接近熟悉的食物来源时，它们也会使用嗅觉线索。当风从一个固定的方向吹来时，这是它们的沙漠栖息地的特征，蚂蚁不会直接接近喂食器。它们宁愿在食物来源的下风处行驶一段距离，以捕捉从食物中散发出来的气味。它们顺着气味的风向，快速而可靠地找到气味的来源。为了确定潜在的定向策略，对这种接近行为进行了更详细的检查。首先，蚂蚁可能采用“目标扩张策略”，利用气味传播作为食物存在的空间有限指标。在这种情况下，喂食器顺风方向的距离应该由气味羽流的范围（以及，例如，风速）决定。它应该与巢和喂食器之间的距离无关。其次，蚂蚁可能会应用“错误补偿策略”，使用气味细丝作为食物来源的指导。在超过最大导航误差的范围内，顺风方向将引导蚂蚁安全地穿过气味指南。在这种情况下，喂食器顺风方向的距离应与喂食器的距离大致呈线性增加。我们的研究结果明确支持第二种策略。当喂食器建立在距离巢5-75米的距离时，食物下风的距离从0.7米线性增加到3.4米。这一结果与风速或风向无关。它转化为蚂蚁对其导航误差在3到8度范围内的估计。
During foraging trips, desert ants Cataglyphis fortis do not rely only on their well-studied path integration system, they also use olfactory cues when approaching a familiar food source. When a wind is blowing from a constant direction, as is characteristic of their desert habitat, the ants do not approach the feeder directly. They rather steer some distance downwind of the food source to pick up odour filaments emanating from the food. They follow this odour trail upwind, and find the source quickly and reliably.This approach behaviour was examined in more detail in order to identify the underlying orientation strategy. First, the ants may employ a 'goal expansion strategy', using odour spread as a spatially limited indicator for the presence of food. In that case, the distance steered downwind of the feeder should be determined by the range of the odour plume (and, for instance, wind speed). It should be independent of the distance between nest and feeder. Second, the ants may apply an 'error compensation strategy', using odour filaments as a guideline towards the food source. Steering downwind by a margin just exceeding their maximum navigation error will lead the ants safely across the odour guide. In that case, the distance steered downwind of the feeder should increase more or less linearly with the nest-feeder distance.Our results unambiguously support the second strategy. When feeders were established at distances of 5-75 m from the nest, the distances steered downwind of the food increased from 0.7 m to 3.4 m in a linear fashion. This result was independent of wind speed or wind direction. It translates into an ant's estimate of its navigation error within a range of 3 degrees to 8 degrees.