Colin Donihue

This Fall, one of my big data-driven dissertation chapters was published in Functional Ecology. The paper is called “Feed or Fight: Testing the impact of food availability and intraspecific aggression on the functional ecology of an island lizard.”

Long story short: we found that lizards on small islands were larger than lizards on big islands. Even more interesting though was that we found these small island lizards had proportionally stronger bites, that means, even controlling for the differences in body size, these lizards were biting especially hard. Now there are two big reasons we might expect lizards on small islands to have harder bites: one, hard bites enable them to eat more defended food, things like beetles and snails, that they wouldn’t have to eat on a big island with lots of juicy insects. Another explanation is that on small islands, lizards need a strong bite force to fight off other lizards and protect valuable resources – food, territories, or access to mates. Both stories make sense, but we set out to test which proved to be the stronger driver for P. erhardii in the Cyclades.

It turns out the answer is that bite force seems to be more related to the levels of lizard-on-lizard competition between islands. After flushing the stomachs of hundreds of lizards and painstakingly identifying all those little bug parts (see post here) the diets of the lizards weren’t all that different (at least in terms of hardness).

With the help of my brother, Ross, we’ve put together a video to talk about the paper. Give it a look here! He did a tremendous job of it! And (shameless plug) if you’re looking for a videographer for your own work, give him a call!