For the Birds: Violet-green Swallows
Wednesday, May 1, 2013
Violet-green Swallow feeding young by John Riegsecker |
Violet-green Swallows
By Christine Southwick
Violet -green Swallows are lovely, lively and only breed in western North America. They winter in Central and northern South America, and have a breeding range from Mexico up to Alaska.
Male Violet-greens are strikingly colored with bright green on their backs, and glossy violet on their rumps; the females’ feathers are a duller version of these colors. Juveniles are brownish, with gray-brown bellies.
Aerial foragers, feeding exclusively on insects, Violet-green Swallows arrive in Shoreline every year sometime in April, depending upon our moderate weather to provide flying insects to fuel both their migration and nesting success. Usually flying higher than other local swallows, they can be seen flying low over open water during cool weather to harvest the lower flying insects. These swallows are usually found in flocks, often with other swallow species, and it is not unusual to find Violet-greens resting on telephone wires with Barn, Tree, and Northern Rough-winged Swallows.
Violet-green Swallow nestling with bug Photo by John Riegsecker |
Violet-green Swallows nest in tree cavities, old woodpecker hole in snags, cliffs, buildings, and sometimes nest boxes. Monogamous, both male and females build their nest for their four-to-six nestlings, and both parents feed their young. They may build an isolated nest, or build in a small colony.
They have adapted to breeding in a wide habitat ranging from open water, wetlands, prairies, open forests, and even clearcuts. While this species seems to prefer forest edges with large snags, these flying insectivores will even breed in urban areas, especially within western Washington’s wetter zone
After breeding, but before the fall migration, Violet-greens usually move to higher elevations, following flying delicacies of mosquitos, mayflies, butterflies and moths. Every year Violet-greens have been sighted flying above Mt. Rainier meadows. They commonly migrate southward along ridges and major rivers, and often thousands collect in Klickitat County located in south-central Washington.
Note white "saddle-bags" on flying Violet-green Swallow photo by Bill Anderson |
Violet-green Swallows can be hard to distinguish from Tree Swallows, especially when they are flying. Violet-greens have, what birders call, the diagnostic white “saddle-bags” on the sides of their rump, just before the tail. If the swallow is sitting on a branch or wire, look for white above the eye. If the white goes above the eye, then you have ID’d a Violet-green Swallow. If it is does not, then it is a Tree Swallow. Also, the wings extend beyond the tail of a perched Violet-green Swallow, but not of a Tree Swallow.
Next time you spot swallows, look for the lovely Violet-green Swallow.
Christine Southwick is a Board member of the Puget Sound Bird Observatory and is their Winter Urban Color-banding Project Manager. She has completed the 40-hour class to become a National Wildlife Federation Certified Wildlife Habitat Steward.
For previous For the Birds columns, click the link under the Features section on the main webpage.
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