Some months ago, I posted a quick analysis of a dataset from 2010 on the movement rates of green anoles (Anolis carolinensis) in the presence and absence of brown anoles (Anolis sagrei) on spoil islands in Mosquito Lagoon, FL. At Jonathan Losos’s urging, Yoel Stuart and I turned this blog post into a paper, which was recently published in Breviora.
The story has not changed since the blogpost (though the analyses are now slightly more sophisticated): male and female green anoles seem to respond differently in their movement behaviour to the presence of brown anoles. There are many possible reasons for these differences, discussed in the paper, that can be summarized as “variation in the motivation for movement between the sexes.” Do read the paper if you’re interested in further details, but be forewarned that we engage in quite a bit of speculation because of one simple fact: compared to what is known about movement rates of male anoles, we know much less about how movement rates in female anoles vary with microhabitat.* Similar disparities between what we know about males and females exist in other aspects of anole biology too.
Though the subject matter of our paper is rather niche (anole ecology pun intended), it contains one paragraph that I think is more broadly pertinent:
Much more attention has been paid to the behavioral ecology of male anoles than to that of female anoles (Butler et al., 2007; Losos, 2009). Our results suggest that male and female anoles can differ in their behavioral responses to ecological pressures. Understanding the mechanisms leading to behavioral and ecological variation within a species will therefore depend upon documenting this variation in both males and females, a conclusion that is hardly surprising. It is disappointing that research on fundamental aspects of the biology of even organisms as well-studied as Anolis lizards remains largely focused on males
There are reasonable reasons for focussing research on males. Male anoles are indeed often easier to spot in the field, and are certainly easier to catch. And incorporating an effect of sex into our statisical models will require us to double our sample sizes. But in many species, observing and catching females isn’t so difficult as to excuse not studying them. For example, in the last month or so, my undergraduate collaborator Rachel Moon and field assistant Barbara Da Silva have measured the ecology and morphology of over 300 Anolis sagrei females—an enviable sample size in any circumstances.
Females have been ignored in all sorts of studies of all sorts of organisms. The absence of female subjects in biomedical trials, for instance, has far more serious consequences than the gaps in our knowledge of the biology of female anoles. Nonetheless, given that many of us are dedicating some portion of our lives to understanding these animals, making sure that we don’t ignore half of them seems like a worthwhile goal.
*This gap exists for two reasons: some previous studies don’t sample females, others sample both sexes but don’t distinguish between them.