National Geographic Young Explorer Neil Losin is a biologist, photographer, and filmmaker pursuing his Ph.D. in UCLA’s Department of Ecology and Evolutionary Biology. Neil studies the evolution of territoriality in invasive lizards called “anoles” living in South Florida.
An occupational hazard
When I’m working in the field in Florida, I get bitten by dozens of anoles every day. I can’t blame them–if I were suddenly captured by an enormous creature wielding a noose on a fishing pole, I’d probably bite my captor too! Luckily, the bites aren’t too painful; anoles are generally small (a few inches long and about one-quarter of an ounce in weight), and their tiny teeth rarely break the skin. Still, until recently I never imagined that I’d actually be encouraging my research subjects to bite.
Why measure bite force?
That changed after my 2010 field season, when I discovered that crested anoles (Anolis cristatellus) had a subtly different head shape in Florida – where they are an invasive species–than in their native range of Puerto Rico. In lizards, head shape is related to “bite force,” the amount of force an animal can exert between its jaws. I found that Florida’s crested anoles had more robust heads than Puerto Rico’s crested anoles, suggesting that they might also be capable of biting harder.
This year, one of my goals was to measure the bite force of crested anoles directly. If bite force is, in fact, greater in Florida than in Puerto Rico, what would that mean? Well, it would suggest that something about Florida’s environment favors individuals that can bite harder. Maybe crested anoles encounter insects with particularly hard exoskeletons in Florida. Or perhaps a powerful bite helps male crested anoles defend territories against rival species in Florida that do not occur in Puerto Rico. Either way, the first step is testing whether native and invasive crested anoles differ in bite force.
Measuring bite force in Florida and Puerto Rico meant, of course, traveling to Puerto Rico (oh, the injustice!). While I was there, my friend Nate Dappen and I filmed this short video to show how – and why – one measures a lizard’s bite.
To see a previous episode of Field Vision featuring my work in Florida, click here.