A Barred Owl at the Oregon Zoo perches in the bough of a tree in his enclosure. Normally, this exhibit is in near total darkness and since you aren't allowed to use flash (a rule I respect, but too many other's don't) he is very hard to photograph. This day however, they must have been simulating daylight for him as the lights were on bright enough to get this great portrait shot of both his face and the distinctive patterns of his back from which he gets his name.
Where the two species ranges come in contact, the Carolina and Black-capped chickadees occasionally hybridize. Hybrids can sing the songs of either species, or might sing something intermediate.
In winter, Carolina Chickadees live in flocks of two to eight birds and defend areas against other flocks. Dominant birds in these flocks establish breeding territories in the summer that were part of the winter flock's range.
The pair bond between a male and female Carolina Chickadee can remain intact for several years. The probability that a pair will remain together seems to vary among populations, with nearly all pairs remaining together in subsequent years in a study in Texas, but only half staying together in a study in Tennessee. If a nest attempt fails, a female may seek out a new male on a different territory.
Juncos are the "snowbirds" of the middle latitudes. In the eastern United States, they appear in all but the most northern states only in the winter, and then retreat each spring. Some juncos in the Appalachian Mountains remain there all year round, breeding at the higher elevations.
These residents have shorter wings than the migrants that join them each winter. Longer wings help the migrants fly long distances.
The Dark-eyed Junco includes five forms that were once considered separate species. The "slate-colored junco" is the grayest, found from Alaska to Texas and eastward. The "Oregon junco" is boldly marked blackish and brown, with a distinct dark hood, and is found in the western half of the continent. The "gray-headed junco" has a brown back and gray sides and lives in the central Rocky Mountains. The "white-winged junco" is all gray with white wingbars, and breeds only near the Black Hills of South Dakota. The "Guadalupe junco" of Baja California is dull and brownish.
Two other forms may be distinguishable: the "pink-sided junco," a pale version of the Oregon junco, living in the northern Rocky Mountains, and the "red-backed junco," a gray-headed junco with a dark upper bill, found in mountains near the Mexican border.
The Dark-eyed Junco is a common bird at winter bird feeders across North America. Data from Project FeederWatch show that it is often the most common feeder bird in an area, and it is on the top-ten lists of all regions except the Southeast and South-Central (where it is 11th and 12th, respectively).
The Red-bellied Woodpecker competes vigorously for nest holes with other woodpeckers, in one case even dragging a Red-cockaded Woodpecker from a nest cavity and killing it. But it is often evicted from nest holes by the European Starling. In some areas, half of all Red-bellied Woodpecker nesting cavities are taken over by starlings.
Stores food in cracks and crevices of trees and fence posts. The woodpecker does not appear to defend its caches from other birds or mammals.
The male Red-bellied Woodpecker has a longer bill and a longer, wider tongue tip than the female. These adaptations may allow the male to reach deeper into furrows to extract prey and may allow the sexes to divide up the resources in one area.
The House Finch was originally a bird of the southwestern United States and Mexico. In 1940 a small number of finches were turned loose on Long Island, New York, and they quickly started breeding. They spread across the entire eastern United States and southern Canada within the next 50 years.
The red or yellow color of a male House Finch comes from pigments that it gets in its food during molt. The more pigment in the food, the redder the male. Females prefer to mate with the reddest male they can find, perhaps assuring that they get a capable male who can find enough food to feed the nestlings.
When nestling House Finches defecate, the feces are contained in a membranous sac, as in most birds. The parents eat the fecal sacs of the nestlings for about the first five days. In most songbird species, when the parents stop eating the sacs, they carry the sacs away and dispose of them. But House Finch parents do not remove them, and the sacs accumulate around the rim of the nest.