Bird Lore: Violet-green Swallow
Even when it is cool and cloudy, nothing quite says summer like the presence of swallows engaging in aerial acrobatics over the Edmonds marsh, Lake Ballinger, and other sites where flying insects abound. Swallows do not all migrate at once. The Tree Swallow is the earliest migrant, arriving in Washington in early March. That species is followed quickly by the Violet-green and then the Barn Swallow, both of which can be seen regularly in Edmonds during the summer months. There are other swallow species in Washington but rarely seen in Edmonds.
The Violet-green Swallow is widespread across Washington and can be found at all but the very highest elevations in Western Washington. It migrates near water, such as along coast lines, rivers, and lakes. It nests in tree cavities, artificial nest boxes, and even in rock crevices of cliffs. It nests both in isolated pairs as well as in small colonies. The nest is a cup of grass and twigs lined with feathers. Four to six eggs are incubated mainly by the female. Both parents feed the nestlings and the young leave the nest about three weeks after hatching.
Swallows forage in flight, catching insects in the air. The Violet-green Swallow often flies higher than other swallows but it does feed low over ponds, particularly in bad weather. It eats a variety of insects, including flies, wasps, winged ants, bees, beetles, and moths, among others. If you watch the Violet-green and Barn Swallows foraging at the marsh, you will notice that the Barn Swallows tend to fly and forage at a lower level than do the Violet-greens. The white rump sides on the Violet-green Swallow wink at you as the bird twists and banks in flight. It is a signature field mark of this species.
Once Edmonds summer residents head south, there are still waves of southbound migrants that move through into October. These are birds that migrated further north in the spring and nested in northern Canada and Alaska. They arrive in single species flocks and tarry long enough to fuel up on insects before continuing south. Enjoy the summer and enjoy these swallows, knowing that once our summer residents leave, the show isn’t quite over.
Vocalizations of the Violet-green Swallow can be heard at this link: http://tinyurl.com/q7grqpj.
– By Carol Riddell
Carol Riddell, author of our new “Bird Lore” feature, manages the bird education displays, on behalf of Pilchuck Audubon Society and Edmonds Parks & Recreation, at the Olympic Beach Visitor Station.