Keep Your Enemies Closer: Green Anole Seeks Safety in the Coils of a Snake

The head of the Green Anole is circled in white. The tolerance of the Cornsnake was perhaps aided by what appeared to be full belly.

Snakes love anoles, though their affection is seldom reciprocated. Unsurprising. But, it seems a snake/anole relationship which leaves the anole happy and undigested is not beyond the realm of possibility. In a recent natural history note, published in Herpetological Review, James Stroud and I describe an unlikely friendship I happened upon while working as a field technician in Miami FL. While collecting samples and doing routine maintenance on an automatic water sampler in Everglades National Park, I found a Green Anole (Anolis carolinensis) nestled within the coils of a large Cornsnake (Pantherophis guttatus) inside the external battery housing of the sampling unit. At first, my delight was focused on the snake (such encounters were a big perk of the job), but then I noticed a slender head regarding me cautiously from the safety of the coils. After a moment, the lizard slowly pulled its head fully underneath its protector, and I closed the lid on the snake/lizard duo, content the battery was in working condition. It was a cool day, and I was happy that I did not need to disturb the animals.

Given the tendency of snakes to make meals out of anoles, this encounter struck me as odd. After casually mentioning it to James Stroud, he immediately suggested this as a possible incident of kleptothermy, which describes a thermoregulatory process by which an organism regulates its body temperature by stealing the warmth of other organisms. The snake was certainly much larger, and so even though it was a fellow ectotherm, snuggling up to it would have likely provided some increase in thermal inertia. Thermal benefits aside, did the oblivious(?) guardian also provide protection against smaller Cornsnakes, perhaps more used to preying on anoles of that size? Did the lizard even realize what it had decided to make its bed upon when it crawled into the dark confines of the battery housing? We may never know.