Abstract
Dispersal shapes the world around us. At local scales it determines the chance that two individuals will meet. Over larger scales it determines species distributions, and the pace and scale of colonisation of new areas. In spiders, one particular behavioural strategy is responsible for long-distance dispersal. This behaviour involves climbing to a high point and producing long, silken lines that act as sails, carrying the spider up into the air currents and away with the wind, in a process known as ‘ballooning’. Spiders decide actively to balloon, but once airborne, individuals have no control over where they land. Over evolutionary time frames spider decision-making in favour of ‘ballooning’ has enabled them to be among the first pioneer species to colonise new areas, such as oceanic islands as they arise from the ocean floor. Over shorter ecological time frames the decision to balloon explains why spiders readily recolonise a farmer’s field after human farming activity has emptied it of its previous residents. In this talk I will explore some of the factors that lead a spider to making the decision to ‘fly’. I will explore how they are able to do so once the decision is made, and the consequences of their choice for the ecosystems to which they belong.
Speaker
Prof Sara Goodacre from the University of Nottingham, UK
Goodacre's profile page at the University of Nottingham.