Marching with Ants to a New Nest: Colony Composition and Relocation Dynamics of Diacamma indicum

Abstract

In this review, we journey with Diacamma indicum a Ponerine ant over the past decade as they relocate to new nests and discover the challenges they face along the way and how they solve them. Colony relocation is a goal-oriented dynamic task that involves all the colony members and impacts the colonies’ fitness. After explaining how I [SA] initiated this journey, we examine colony composition of this species by analysing data from 1200 colonies collected over the past 13 years. On average colonies contain 89.35 (Standard Deviation = 38.79) adult females, 0.29 (SD = 1.19) males and 56.6 (SD = 42.53) brood items of different development stages and these were significantly impacted by seasonality such that pre-monsoon colonies had the highest numbers. After explaining how colonies are collected and maintained in the lab, we explore the architecture of the subterrain nests in the natural habitat. Colonies live in relatively simple single-chambered nests that do not change significantly across seasons and consist of an entrance tunnel and a secondary runoff tunnel. All members of the colony are recruited to the new nest site by tandem running and this species shows the highest documented tandem running speeds at 4.35 body lengths per second and a path efficiency of 83.95% with only 2.4% of tandem runs being unsuccessful in the natural habitat. Even in lab conditions, when colonies are given defined paths of different lengths, colonies showed significant preference to travel through short paths, highlighting their ability to optimize their path even in the absence of chemical trails. A combination of experiments in the natural habitat and controlled experiments in the lab which are anchored in the umwelt of the organism has enabled us to understand how D. indicum functions and has revealed the selective forces that are operating on the organization and performances of relocation. Our journey has brought to light answers to several questions but has also opened up several more avenues for exploration, branching out in different directions. With time and dedicated minds, we hope to continue on this route to marvel at and unravel the achievements of these superorganisms.