非洲的撒哈拉沙漠可能缺少地标，但它却是各种气味的“大杂烩”。
据美国《科学》杂志在线新闻报道，土壤中的裂缝、一块小木头以及灌木丛，所有这一切都释放着特殊的气味。沙漠蚂蚁(Cataglyphis fortis)能够利用这些气味找到自己的家门。在此之前，研究人员认为它们只能够利用视觉线索来完成这项工作。科学家表示，气味线索在炎热的沙漠中迟早能够派上用场，这是因为蚂蚁自身的生物素很难维持足够长的时间。研究人员在2月27日出版的《动物学前沿》杂志上报告了这一发现。（生物谷Bioon.com）
生物谷推荐原始出处：
Frontiers in Zoology 2009, 6:5doi:10.1186/1742-9994-6-5
Smells like home: Desert ants, Cataglyphis fortis, use olfactory landmarks to pinpoint the nest
Kathrin Steck , Bill S Hansson and Markus Knaden
Background
Cataglyphis fortis ants forage individually for dead arthropods in the inhospitable salt-pans of Tunisia. Locating the inconspicuous nest after a foraging run of more than 100 meters demands a remarkable orientation capability. As a result of high temperatures and the unpredictable distribution of food, Cataglyphis ants do not lay pheromone trails. Instead, path integration is the fundamental system of long-distance navigation. This system constantly informs a foraging ant about its position relative to the nest. In addition, the ants rely on visual landmarks as geocentric navigational cues to finally pinpoint the nest entrance.
Results
Apart from the visual cues within the ants' habitat, we found functional olfactory landmark information with different odours coupled to various ground structures. Here we show that Cataglyphis ants can use this olfactory information in order to locate their nest entrance. Ants were trained to associate their nest entrance with a single odour. In a test situation, they focused their nest search on the position of the training odour but not on the positions of non-training odours. When trained to a single odour, the ants were able to recognise this odour within a mixture of four odours.
Conclusions
The uniform salt-pans become less homogenous if one takes olfactory landmarks into account. As Cataglyphis ants associate environmental odours with the nest entrance they can be said to use olfactory landmarks in the vicinity of the nest for homing.
