Path Integration Controls Nest-Plume Following in Desert Ants

Abstract

The desert ant Cataglyphis fortis is equipped with sophisticated navigational skills for returning to its nest after foraging. The ant's primary means for long-distance navigation is path integration, which provides a continuous readout of the ant's approximate distance and direction from the nest. The nest is pinpointed with the aid of visual and olfactory landmarks. Similar landmark cues help ants locate familiar food sites. Ants on their outward trip will position themselves so that they can move upwind using odor cues to find food. Here we show that homing ants also move upwind along nest-derived odor plumes to approach their nest. The ants only respond to odor plumes if the state of their path integrator tells them that they are near the nest. This influence of path integration is important because we could experimentally provoke ants to follow odor plumes from a foreign, conspecific nest and enter that nest. We identified CO(2) as one nest-plume component that can by itself induce plume following in homing ants. Taken together, the results suggest that path-integration information enables ants to avoid entering the wrong nest, where they would inevitably be killed by resident ants.

Spatial Memory in Insect Navigation

“…These various locations are often inconspicuous ( Figure 1A), and the insects learn them only in terms of the visual surroundings. In other cases, at nests or regular feeding sites, they may supplement the naturally occurring cues with scent marks [13,14] or even architectural constructions. The stingless bee Partamona batesi, for example, collects white river sand and glues it together with resin into a sculptured portico ( Figure 1B) that helps guide the bees on their return [15].…”

Desert ants use olfactory scenes for navigation

“…navigational systems to pinpoint their nest by following a nestproduced odour plume (Buehlmann, Hansson, & Knaden, 2012b).…”

Scene perception and the visual control of travel direction in navigating wood ants

“…Ants are turning out to be particularly informative, because the precision and stereotypy of their routes [17][18][19][20] make it possible to analyse the underlying strategies and mechanisms [21,22]. Ants are also interesting because of the multiple sensory cues that contribute to their navigation, particularly olfaction, with long range cues from wind-borne volatiles [23][24][25] and short-range cues from pheromone trails on the ground [26]. Many species of ants lay pheromone trails to mark foraging routes, and some of these species are also helped by remembered visual cues [27][28][29][30].…”