Aggressive conflict impacts path integration in homing desert ants

The desert ant Cataglyphis fortis inhabits the salt pans of Tunisia, which are characterized by a lack of precipitation, extreme heat, and the complete absence of landmarks perceivable to humans. The individually foraging ants use path integration to find their way back to their nest (Muller and Wehner 1988, Wehner and Muller 2006, Muller and Wehner 2007, Wehner 2008). Additionally, the ants make use of other sensory cues, mainly visual and olfactory landmarks (Wehner and Raber 1979, Wehner et al. 1996, Steck et al. 2009, Buehlmann et al. 2011, Buehlmann et al. 2012, Wehner 2020), to form a robust toolkit for navigation. Since cooperation during foraging is negligible for C. fortis, the impact of intraspecific contact on its navigation has not yet been investigated. Our data suggests that C. fortis considers intraspecific contact, or social cues, to further augment navigation. We show that contact with foreign conspecifics reduces trust in path integration thus broadening search patterns to optimize homing success. Furthermore, we explore the question of how ants navigate their surroundings without having aggressive encounters with neighboring nests and propose a navigational mechanism that might help ants avoid aggressive encounters with individuals of foreign colonies.