Chimney Swifts are nesting in the chimney of a friend's house. A check this morning (Thursday) found three eggs. Usual clutch is four. Incubation of 19 days will begin when final egg laid. That should be today or tomorrow. The nest, attached to the chimney just below a tile junction (hence the shadow on the eggs, from the camera flash) is about 11 feet from the chimney top. The nest is constructed of small twigs the birds break from trees by grasping them with their feet as they fly by. The twigs are secured to the rough wall of the chimney with saliva, which becomes thicker and sticky during breeding season. My friend has built a swift nesting tower, but his chimney has been used for several years, and birds keep returning there, so far ignoring the tower. Only one pair of swifts will use a given nesting site, so if the neighborhood population increases, use of the tower is more likely. Chimneys are becoming scarce; modern houses, even those with fireplaces, often don't offer a proper chimney. Lack of appropriate nesting sites has hurt Chimney Swift populations. Swifts also will nest in abandoned buildings, chimneys and buildings chosen on almost a 50/50 basis, but we're as short on suitable abandoned buildings as we are on chimneys. There is another pair of swifts at the house next door to the one I watch, so neighborhood population growth is possible. Swifts also fly above our house once in a while (a mile from the described site), foraging for insects, but I've never been able to track them to their nesting site. Swifts take insects from the air, and also will flutter close to tree canopies to pluck insects from the leaves. The photos show two views of the nest and eggs in the chimney, one of the pair of swifts as they flew above the house, and a closer look at one of the birds. The birds were in the air when we visited the chimney.
