Eastern Bluebirds

In colder months finding Eastern Bluebirds seems to be feast or famine; either I won't see them at all, or I'll see 3-6 of them hanging out together. Given they look more gray than blue in my picture, I'm assuming these are females (though even the males can look gray in certain light).

A century ago, the Eastern Bluebird was considered to be in danger of extinction due to loss of nesting and loss of foraging habitat. That dire consequence is past us, though Eastern Bluebird populations are still suppressed due to competition for nesting locations for these cavity nesting (bird houses or hollow trees) birds. 

Apparently Eastern Bluebirds are one of the few bird species known to have had twins. Twins in birds implies that 2 birds hatch from the same egg. My suspicion is that twinning happens much more often than we know; in most cases the only way to tell is if we see N number of eggs but see N+1 number of hatchlings, and we just don't monitor every bird nest well enough to get data on this. Between domestic birds and bird-cams trained on eagle/hawk/owl nests though, it does seem like the phenomenon is pretty rare.

November 3, 2021 at Duke Farms
Photo 168431686, (c) jpviolette, some rights reserved (CC BY-NC)


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