We’ve featured a post on biological theft before, under the name of mycocleptism. In that case the thief was a species of beetle that lived off the fungal tunnels of another beetle species, and now we are learning of a different type of behavior: stealing heat. Apparently certain reptiles, which are unable to bask in the sun at night, have found an effective method of transferring warmth that does not involve time travel. Instead, they snuggle up in the nests of birds. Brian Switek reports on the phenomenon for Nat Geo below, but one question that seems to remain unanswered is whether the feathered members of the deal are getting anything out of their reptilian visitors. For example, sea snakes like the ones mentioned in the referenced article are venomous — could it be that their presence in a shearwater nest would protect the birds from potential predators?
You could bask in the sun to remedy the cold. That’s a classic reptile way of working some warmth back beneath those scales. But there’s another option. You could steal your warmth. All you’d have to do is find some seabirds.
There’s a specific term for this warmth-sucking behavior – kleptothermy. The conditions, laid out by François Brischoux and colleagues, are really quite simple. There has to be a warm animal in a relatively cool environment and another animal that can use that body heat to raise their own body temperature. For example, a blue-banded sea krait that got nice and cozy in a wedge-tailed shearwater burrow.
When not in the underground nest, the researchers found, the sea krait had a body temperature of about 89ºF. Pretty warm for an ectotherm. But when the snake coiled up inside the seabird nest, out of the way of the owners, its body temperature was more stable and rose to about 99ºF. This was definitely because of the birds. When the accommodating avians weren’t at home, the lack of their body heat caused the nest temperature to dip to 82ºF.
The snake wasn’t the only reptile to borrow a little body heat. Other reptiles, from lizards to crocodiles, have been known to inhabit the burrows of warmer-bodied animals, as well as termite mounds where the activity of all the little insects keeps the colonies on the toasty side. And in a much broader study published this year, Ilse Corkery and colleagues found that tuataras are little kleptotherms, too.
To read the original article, click here.