Dynamic networks in invasive ant species: modelling flexibility in response to environmental change

Social insects are highly ecologically successful, with ants being among the most dominant groups worldwide. To explain this widespread ecological success, we must understand how they organize their many individual ants into effectively functioning colonies. In one striking form of organization, some of the most dominant ant species spread each colony across multiple social connected nests, a phenomenon called polydomy. All the major invasive ant species have a polydomous nesting system, and polydomy is known to affect foraging success through the formation of a network of nests, connected by trails along which food can be transported. Previous studies of polydomy have focused on static nest networks, while in reality polydomous species, especially invasive ones, flourish in changeable and often unpredictable environments. This project will address the lack of theoretical models of how flexible networks are used to respond to environmental change, for example a fluctuating food supply or challenge from competitors. The primary focus of this project is theoretical modelling; however, there is scope for empirically testing some model predictions on ant colonies in the laboratory or in the field.

Objectives
To model:
a) the development of a functioning nest network as a colony increases in size, considering growth/reproduction trade-off
b) the effects of nest network structure on a colony’s ability to respond to environmental change
c) how the nest network structure of a colony is influenced by conspecific and heterospecific competitors’ nesting and foraging strategies

Economic and environmental impact
Invasive alien species cost Britain at least £1.7bn per year through damage and management costs; the true cost of their impact on biodiversity is likely much higher. Of the ants listed among the 100 most damaging invasive species, all are polydomous. Initiatives such as the EU Biodiversity Strategy are increasingly recognizing the importance of controlling invasive species. This project will shed light on the mechanisms by which damaging invasive species successfully invade unpredictable environments, helping us identify potential control measures.

Skills
The successful candidate will develop a suite of skills with the support of the multidisciplinary supervisory team, in particular theoretical modelling including agent-based simulation modelling and network modelling, advanced data analysis including dynamic network analysis. There is also potential to learn lab- and field-based empirical techniques of working with ants, including radio-tagging and visual tracking. This skillset will put the candidate in a strong position for a future career in ecological and interdisciplinary research.

This project will also be co-supervised by Dr Kate Parr from the Department of Earth, Ocean & Ecological Sciences, University of Liverpool.