"Phidippus pius eyes" by Opoterser. Via Wikimedia Commons
Individual spiders have character and personality, according to a paper published by the Proceedings of the Royal Society B. The paper, titled Individual personalities shape task differentiation in a social spider, gives details of a study into role allocation in spider societies.
It was previously assumed that individuals in social spider communities contributed homogeneously, with all tasks, such as prey capture and colony defence, being performed equally by members.
The study focused on Stegodyphus sarasinorum, a permanently social spider occurring in India and some surrounding countries. Led by Lena Grinsted of Aarhus University in Denmark, over 600 spiders were marked and observed, with tests singling out boldness and aggression. Variances in response showed that individuals were suited to particular roles.
Stegodyphus sarasinorum spiders, marked for identification. Courtesy of Lena Grinsted
Individuals in the test group were highly related and of approximately the same age: the only variable was apparently their personality. The study suggests that task allocation is the result of character traits in individual spiders; personality does not appear to be shaped by random selection of task performance, therefore.
Character and personality are often attributed only to humans, higher order mammals, and birds. Now it appears that arthropods also have more complex behavioral traits than had previously been considered.
Animal behavior is a popular topic in ecology at the moment. Studies of the kind conducted by Grinsted and her colleagues are leading to a new understanding of task performance in natural group settings, with personality assays becoming a useful tool for individual behavior prediction.
For readers interested in animal behavior, Yale University offer a free, open online course which can be found here.
