I’m about to begin a series of posts on social spiders – yes, those creepy crawly arthropods we all despise – to give some background information on a research project that my PI and I have been developing for a while (now in pre-proposal stage). My hope is that this series of bite-sized bits of my project, the theory behind it, and the journey of the research itself will be interesting enough to turn some of the fear we have into curiosity. As a child I was terrified of spiders, and made my father ‘take care of’ any of the unfortunate few that wandered into my room; but through all this research, I’ve actually developed a (very small) fondness for the little guys, and I hope I can share that fondness with you.
We’ll start this introduction by discussing the study organism itself – the spider. In this study, we’ll be looking at closely related spider species that differ dramatically in one major type of behavior – sociality. There are three ‘types’ of this behavior – solitary, subsocial, and social.
Solitary spiders are the ones most of us are probably familiar with – you know, the spider that chills out on its own web or wanders around on the ground by itself. It meets with other spiders for mating, but that’s the extent of its desire to socially interact.
Subsocial spiders are those that engage in some social behaviors – perhaps they live together or engage in cooperative prey capture maneuvers, but they also have some kind of obligate solitary phase. This could be a particular season of the year or a particular age that they spend alone, or they could even have communal webs but with marked, individual territories. The behaviors here are really diverse.
Lastly, you have the social spiders. For people with arachnophobia this is probably the WORST thing ever because if you find one spider, you know there are bound to be many more nearby. Social spiders engage in cooperative maternal care, nest maintenance, and prey capture behaviors and live together pretty much 24/7 – except during dispersal, when young spiders leave the nest to venture out into the world alone.
Social spiders come in various shapes and sizes just like the more familiar solitary spiders; you have larger huntsman in Australia that can have up to 300 spiders in a colony and the smaller Anelosimus (the spiders I’ll be working with, known as cobweb spiders) found throughout the Americas – Anelosimus eximus, a species I’ll be working with frequently, can have tens of thousands of spiders in a web (found as far north as Panama, though there are other Anelosimus in the US). There are other social spiders found throughout the world, in varying colors, numbers, sizes, and with varying behaviors.
That’s it for today’s introduction to the project – be sure to check back for future installments on spider brains, brain resource allocation theory, social spider behavior, and more!