Why do birds pretend to be caterpillars

The Chicks of some South American birds have unusually bright coloring, which makes them look like tasteless hairy caterpillars.

Newborn Chicks are vulnerable to predators, and therefore they must behave with extreme caution and to be inconspicuous. So it is not surprising that even bright birds Chicks look pretty unattractive, because their goal is not to attract attention.

However, gray ouline Laniocera hypopyrra from South America, things are exactly the opposite. Adult birds have a grey, nondescript plumage, whereas the appearance of the Chicks, to put it mildly, it is striking – they are covered with bright orange feathers and down. The oddity of the contrary, it would seem that common sense showed up not so long ago: in 2012, "The Wilson Journal of Ornithology" published an article in which, in addition to aulani, described sister species sorokopudova of cotinga. And cotinga and auline Chicks because of their bright plumage was very to stand out of the nest and surrounding vegetation, but because they could easily detect birds of prey or, for example, primates.

In that work the authors compared the Museum specimens of adult birds and Chicks for their behavior in the wild, they are not observed. So zoologists could only assume that the benefit may be Chicks from the bright colours in their feathers and the fluff contains some kind of toxin (in fact external brightness are often accompanied by virulence), whether they are disguised as someone else, for whom the predator will not eat.

Further research showed that it is the latter – at least for gray aulin. Gustavo Londoño (Gustavo A. Londoño) University of California, riverside (USA) together with colleagues from Columbia University Valle was able to take video like a little auline crawl through the nest and from time to time nuzzled his head from side to side, like caterpillars. Chicks imitate a specific insect, large, 12-inch hairy caterpillar that lived on the same trees on which auline building a nest. This caterpillar size was just about the chick and her hairs contain an irritant toxin, making it extremely unappetizing.

Strange mimicry was not limited to the color. In an article in "The American naturalist is," the authors write that the Chicks on the tips of the feathers sat a long white feather yarn, very similar to the hairs of the caterpillar.

Video Chicks and adult birds

  

you can also admire the very caterpillar



This kind of mimicry, when a harmless species copies the appearance of the toxic form, called Badowski, and are most commonly found in insects (classic example:-hoverflies, similar to OS). However, birds have anything like that until now were not observed. Predators ruin about 80% of nests of grey aulin, so obviously due to the lack of a little bit of effective protection on the part of the parents of the Chicks had no choice but to pretend to be caterpillars.