Cryptic functional diversity in ant tandem runs

Abstract

Ants have evolved diverse recruitment methods to guide colony members to valuable resources, such as food or nest sites. One of these methods, tandem running, consists of an informed leader directly guiding a naive follower every step of the way from nest to resource. Although this behavior appears superficially similar in the different ant taxa in which it has independently evolved, this similarity could conceal underlying functional and mechanistic differences. Here we present a combined network and information-theoretic analysis, which reveals fundamental differences in the tandem recruitment between two distantly related ant genera, Temnothorax and Diacamma. Temnothorax uses tandem running to recruit additional recruiters, whereas Diacamma uses it principally to move the passive majority of the colony, a task that Temnothorax accomplishes with a different behavior, social carrying. Accordingly, the structure of the tandem run recruitment networks of Diacamma was different from those of Temnothorax, with Diacamma networks more closely resembling the social carrying networks of Temnothorax. Furthermore, an information-theoretic analysis of the spatial trajectories of leaders and followers revealed that Diacamma tandem runs lack bidirectional information flow, the signature of route-learning in Temnothorax tandem runs. These results suggest that Diacamma uses tandem runs not to share information, but to transport nestmates. By quantifying the cryptic diversity of communication behavior, this study increases the resolution of our understanding of animal societies.

Extinct and extant termites reveal the fidelity of behavior fossilization in amber

“…All movement trajectories and source codes for analyzing them are available at Github: https://github.com/nobuaki-mzmt/tandem-fossil ( 54 ). µCT data in DICOM (digital imaging and communications in medicine) format and codes are available at Zenodo https://doi.org/10.5281/zenodo.10557251 ( 55 ).…”

Social learning of navigational routes in tandem running acorn ants (Temnothorax nylanderi)

“…During nest relocations, tandem running helps colonies assess the quality of new nest sites and migrate more efficiently (Mizumoto et al, 2023;Stuttard et al, 2015). Tandem running has been described in dozens of ant species and is likely to have evolved several times independently in phylogenetically distant ant groups belonging to at least 4 subfamilies (Glaser & Grüter, 2022;Mizumoto et al, 2023). A common feature of ant species that use tandem running is that they have relatively small colony sizes (Beckers et al, 1989;Glaser & Grüter, 2022).…”

“…During foraging, tandem running may help colonies visit food sources of better quality and defend them as a group against competitors (Glaser et al, 2021;Glaser & Grüter, 2023;Goy et al, 2021;Shaffer et al, 2013). During nest relocations, tandem running helps colonies assess the quality of new nest sites and migrate more efficiently (Mizumoto et al, 2023;Stuttard et al, 2015). Tandem running has been described in dozens of ant species and is likely to have evolved several times independently in phylogenetically distant ant groups belonging to at least 4 subfamilies (Glaser & Grüter, 2022;Mizumoto et al, 2023).…”