Brooklyn Bird Watch: November 18
American Redstart. Scientific Name: Setophaga ruticilla
Today, Brooklyn Bird Watch features a Heather Wolf photo of a female American Redstart. The Cornell Lab describes this unique bird as “a lively warbler that hops among tree branches in search of insects. The male American Redstart is coal-black with vivid orange patches on the sides, wings, and tail.”
This species in general seems to be an appropriate selection for October as we see that Sarah LeFoley, writing for the Houston Audubon website, reaches for Halloween imagery to describe the male Redstart.
“It’s a monarch butterfly, it’s a flying jack-o-lantern; No, it’s an American Redstart! The mature male American Redstart looks like it’s perpetually dressed for Halloween with its stark black head, breast, back, wings, and tail, and bright orange patches on the flanks, wings, and sides of the tail to contrast the white belly.
The females and immature birds are more subdued with gray heads, breasts, backs, wings, and tails, and yellow patches. The patches are thought to startle and help capture prey when redstarts flash their tails and move their wings. These birds will catch insects in midair, a less common behavior among other warbler species. They will also eat insects off of leaves, twigs, and other surfaces. The American Redstart’s diet consists mainly of insects such as flies, moths, caterpillars, aphids, spiders, and crane flies.”
And Glenn Olsen for the same website writes: “The females are just as beautiful though softer in contrast with a light gray head and bright yellow patches in the flight and tail feathers.
The American Redstart employs several foraging techniques, one of which is quite similar to flycatchers. The redstart may dart upwards to pluck an insect from mid-air and then appears to float back down on spread wings and tail; the orange patches in the wings and tail flashing like a flame. These sorties for insects can be quite acrobatic and interesting to watch as they forage, most frequently in the low to mid range canopy.”
According to whatbird.com, the American Redstart is in fact sometimes referred to as “the butterfly of the bird world” because of its quick fluttering motions and bright orange color on the wings and tail.
The male American Redstart sometimes has two mates at the same time. While many other polygamous bird species involve two females nesting in the same territory, the redstart holds two separate territories that can be separated by a quarter-mile. The male begins attracting a second female after the first has completed her clutch and is incubating the eggs.
The female usually produces 4 white eggs with brown specks. The nest is a neat, delicately structured cup of grass, bark shreds, plant fibers, and spider web gauze lined with fine grass and hair, and placed in a fork in sapling branches, or next to the trunk of a tree.
Whether or not one is a professional bird person, the various courtship rituals of birds, sometimes exotic and beautiful, and sometimes minimal, have for some reason always fascinated people. The American Redstart is no exception.
During courtship, males will often chase potential mates in a somewhat aggressive manner, and interested females will respond by flying a short distance, then giving a tail-spreading display. Males often give two types of displays towards females: fluff displays and bows. Fluff displays consist of fluffing the body feathers, particularly the bright orange flanks. There is evidence that brighter orange flanks correlate to higher levels of male parental investment, and raising these feathers may serve to advertise parental quality. Bow displays are typically given later in courtship, when a male sleeks his feathers, lowers his breast to the ground, and holds his head vertically.