Top Photo: Male northern cardinal catching some rays on the boardwalk.
While it may calm and warm the cardinal in the above photo to expose itself to the sun’s rays, research suggests that there’s more going on than just relaxing in the sun.
When a bird turns its side to the sun, spreads out its flight feathers and exposes as much of its body as it can to the direct rays of the sun it may be trying to rid itself of parasites and their eggs, whether directly or indirectly.
Feather lice and their eggs have been known to die from exposure to high temperatures of 140 degrees or more after just a few minutes, that is, if they stay put. Obviously, the insect’s eggs can’t get up and walk away from the heat. They probably bake in place. But, the adult lice and other parasites hitching a ride on the bird may flee the heat and scurry around to the other side of the bird. In doing so, they may be exposing themselves to capture and consumption by the bird whose feathers they’ve infiltrated.
Birds seem to tolerate the heat fairly well, though they’re often observed with their bills agape and panting. I guess bearing two or three minutes of intense heat (which is about as long as I’ve observed songbirds hold the position) is worth the effort to get rid of the mites, lice, or flat flies that suck the bird’s blood.