Investigation of tandem leaders’ tendency to become followers, their relative positions and the importance of information they carry during colony relocation in an Indian ant

Das, Susnato (2021) Investigation of tandem leaders’ tendency to become followers, their relative positions and the importance of information they carry during colony relocation in an Indian ant. Masters thesis, Indian Institute of Science Education and Research Kolkata.

Text (MS Dissertation of Susnato Das (16MS158)) 16MS158_Thesis_file.pdf - Submitted Version Restricted to Repository staff only Download (2MB)

Abstract

Colony relocation in ants has been extensively studied in many species. Most of the ant species rely upon chemical trails for relocation while some relocate via carrying or walking. However there are species that use a more primitive method of transport known as tandem running where one ant leads another nestmate to a target location while maintaining physical contact. This study involves understanding various aspects of colony relocation in an Indian ant species Diacamma indicum that uses tandem running as the sole means of relocation. The process of tandem running is completely dependent on tandem leaders who carry out the entire transport process. In this study, we addressed three basic questions. The first component of the study dealt with the construction of a Leadership Index that would rank tandem leaders in a colony on the basis of their overall contribution to the process of relocation. The index constructed is the first of its kind and was able to assign more unique ranks to tandem leaders in a colony compared to the previously used criterion for ranking. The second component addressed the importance of Leader Following Leader (LFL) in reunification of a colony. Even in the absence of LFLs, colonies were seen to invariably reunite. However the process of reunification was around 2.3 times slower and hence less efficient. This suggests that LFLs act as a catalyst in the process of reunification. There were leaders who switched their initiation and/or destination sites at different points during relocation and they are particularly important for reuniting the colony. The third component of the study examined if prior information of an alternative nest is useful to ant colonies when they relocate. In this part of the study, ants discovered two nesting options but relocated to only one. This allowed us to ask if information about location of the other nest that was previously discovered would be useful if the colony was faced with another relocation. It was seen that prior information was useful as it improved relocation dynamics. In the first chapter, the Leadership Index allowed us to understand the contribution of tandem leaders in a colony relative to one another. The second chapter showed that information sharing among tandem leaders via LFL was particularly important and it saved relocation time. Finally, the third chapter showed that tandem leaders could make the best use of prior information of an alternative nest during relocation. Hence this study allows us to understand and appreciate the efforts of tandem leaders during colony relocation in this species.

Actions (login required)

View Item