Desert Ants Locate Food by Combining High Sensitivity to Food Odors with Extensive Crosswind Runs

Abstract

Desert ants feeding on dead arthropods forage for food items that are distributed unpredictably in space and time in the food-scarce terrain of the Saharan salt pans [1]. Scavengers of the genus Cataglyphis forage individually and do not lay pheromone trails [2]. They rely primarily on path integration [3] for navigation and, in addition, use visual [4] and olfactory cues [5-7]. While most studies have focused on the navigational mechanisms of ants targeting a familiar place like the nest or a learned feeding site, little is known about how ants locate food in their natural environment. Here we show that Cataglyphis fortis is highly sensitive to and attracted by food odors, especially the necromone linoleic acid, enabling them to locate tiny arthropods over several meters in distance. Furthermore, during the search for food, ants use extensive crosswind walks that increase the chances of localizing food plumes. By combining high sensitivity toward food odors with crosswind runs, the ants efficiently screen the desert for food and hence reduce the time spent foraging in their harsh desert environment.

A Neurocomputational Model of Goal-Directed Navigation in Insect-Inspired Artificial Agents

“…However, both models apply straight paths before homing, which results in smaller path integration errors compared to random foraging as observed in insects. Furthermore, many desert ant species were measured to freely forage average distances of 10–40 m depending on the species (Muser et al, 2005), whereas some individuals travel even up to multiple hundred meters (Buehlmann et al, 2014). Our foraging time has been adjusted for realistic foraging distances, and if we reduce the foraging time in our model, we achieve similarly small positional errors as previous models.…”

Experience‐related reorganization of giant synapses in the lateral complex: Potential role in plasticity of the sky‐compass pathway in the desert ant Cataglyphis fortis

“…They exhibit an age-related polyethism from interior worker to forager (Cataglyphis bicolor: Wehner and Toggweiler, 1972;Schmid-Hempel and Schmid-Hempel, 1984). Solitary Cataglyphis fortis foragers search for food over distances of more than 1000 m (Buehlmann et al, 2014) and return to their inconspicuous nest entrance in an almost straight line. The ants inhabit almost featureless salt flats where they predominantly use path integration (Wehner, 1982;Wehner and Srinivasan, 2003) based on stride integration (Wittlinger et al, 2006(Wittlinger et al, , 2007 and a polarized skylight-based visual compass (reviewed in Wehner, 1994;Wehner et al, 1996;Wehner and M€ uller, 2006).…”

Species-specific differences in the fine structure of learning walk elements inCataglyphisants

“…Cataglyphis fortis inhabiting North African chotts and sebkhas cover the largest distances compared with other desert ant species (Wehner, 1983(Wehner, , 1987a. Their paths can be longer than 1 km and their maximal foraging distances more than 300 m from the nest (Buehlmann et al, 2014). Cataglyphis noda, native to Greece, search for food closer to the nest, but still cover large distances , as do Cataglyphis bicolor [Wehner, 1987a; note that in that publication (and others: Harkness, 1977;Wehner et al, 1983), C. noda belonging to the bicolor species group, i.e.…”