In which I get a message saying, “Swallows are back!”
On Saturday morning, after we went out for a brief outing, my husband headed out of house to go to the vineyard. He still had a some pruning to do, and hasn’t a great deal of time to get the work completed. Soon after he left the house I got a text message from him: “Swallows are back!”
My heart lifted, I smiled, and I headed out to welcome our returning neighbors. I say returning, because there is a good chance that the swallows who arrived last week either nested here last summer or hatched here.
Most songbirds use a nest for just a single clutch or season, then build a new one – if they survive to breed again. However studies have shown that most barn swallows returned to the same colony, with 44 per cent of pairs reoccupying the same nest. This is remarkable given the length of a swallow’s return migration from its wintering grounds in central and south America. It is incredible to think that these little birds may have spent the winter in Columbia, which means that over the last few months they completed a 3,100 to 3,500 miles (about 5,000 to 5,600 kilometers) journey and somehow found their way back to our barn.
Here in the Pacific Northwest, barn swallows are harbingers of spring’s longer, warmer days. Warmer days awaken long-dormant insects, and barn swallows- like most little insectivores - follow their food, which are mostly flies and mosquitoes, but also beetles, bees, wasps and so on. They summer here, then when “summer” moves south, they do too, following available food all the way to northeastern South America and the Caribbean basin. Just think of it. These tiny birds, which you could easily hold in the palm of your hand, fly thousands of miles every year.
The barn swallow (Hirundo rustica) is a medium-sized songbird, about the size of a sparrow. While it is average-sized, it’s far from average-looking! Its back and tail plumage is a distinctive steely, iridescent blue, and it has a light brown or rust belly and a chestnut-colored throat and forehead. Their long forked tail and pointed wings also make them easily recognizable. It’s these wings, tail and streamlined bodies that make their fast, acrobatic flight possible. Both sexes may look similar, but females are typically not as brightly colored and have shorter tails than males. When perched, this swallow looks almost conical because of its flat, short head, very short neck, and its long body.
Although the average lifespan of a barn swallow is about four years, a ringed North American bird lived more than eight years and a ringed European swallow was on the books for more than sixteen years.
Like all swallows, the barn swallow is diurnal – it is active during the day, from dusk to dawn. It is an agile flyer that creates very acrobatic patterns in flight. It can fly from very close to the ground or water to more than 98 feet (30 m) in the air. The species may be the fastest swallow, as it’s been recorded flying at speeds close to 46 miles per hour (75 kilometers per hour.) When not in flight, the barn swallow can be observed perched on fences, wires, TV antennas or dead branches.
Both male and female barn swallows sing individually and in groups in a wide variety of twitters, warbles, whirrs and chirps. They give a loud call when threatened, which causes nearby swallows to react by leaving their nests to defend the area.
Barn swallows are comfortable in our big cities, small towns, neighborhoods and farms. While other swallow species prefer to nest in natural structures hidden from view, such as cliffs or tree cavities, barn swallows build mud nests out in the open, so we get see the entire nesting cycle. Any straight-edged overhang that is protected from the rain will do: it might be tucked under a bridge strut, a porch, a roof overhang, or a barn rafter, hence their common name. In our case, they live in our barn. The rafters of the ceiling in our barn are full of the little mud nests that they have made over years. Barn swallows construct nests formed from mud pellets that they collect from puddles in their beaks. Their nests are cup shaped, and the inner cup is lined with grass, hair, and feathers. Unlike their cousins the cliff swallows, which nest in large groups, barn swallows nest in pairs.
Brian and I love the barn swallows. In fact, we named our farm after them, Swallow Hill Farm. With their dark blue backs and almost golden breasts they’re beautiful. They swoop and soar across the big sky above our farm, making their distinctive chuckling and twittering call. And they eat insects, thousands of them, expertly catching a variety of insects in midair with their wide-gaped bills. Often at dusk, I watch them diving down on the clouds of little insects that rise from the grass at that time of day. Barn swallows also eat some berries, seeds, and dead insects from the ground, particularly during bad weather, and will fly several miles from their nest site to forage. It is thought that swallows spend more time on the wing than any other songbird. As their name suggests, upon finding food they swallow it whole. There is no biting, chewing or stashing it for later. Just as they eat on the wing, swallows drink mid-flight; as they fly over water they dip their bill to the surface to drink.
Soon after they arrive in their summer home the pairing up process begins. Courtship involves aerial chases. Mated pairs then sit close together when they perch, touching bills, and preening each other's feathers. After forming, a pair will remain together throughout the nesting season, making the barn swallow “socially” monogamous. In truth, mating with other individuals is common for both sexes, and so the species is genetically polygamous. However, pairs that successfully mated in the past may reconnect for several nesting seasons in a row. Unpaired adults may sometimes become “helpers” to a pair for the summer, assisting in the nest’s defense and building, and even incubating the eggs. Several pairs may nest in the same immediate area, which is what happens in our barn. Last year seven pairs set up house in the rafters of the building.
Barn swallows are dedicated builders. They pick up mud from places like river banks or puddles, and fibrous material, like grass, and arrange them into cup-shaped nests. The interior of their nests are lined with grass, hair, and feathers. A pair of swallows can make over 1,000 trips, bringing back a mouthful of mud on each trip, to build a new nest. Because this is hard work, barn swallows frequently reuse a nest built in a prior year. When reused, new mud can be added to the structure and the nests lining is often changed.
Typically 44 to 55 days go by from the time when the nest building begins to when the young leave the nest. When the nest is ready, normally in May, swallow pairs start mating and egg-laying. Both parents take turns incubating three to five eggs, which hatch after 12 to 17 days, and both parents care for the young, which begin to fly at 20 to 25 days of age. Many times Brian and I have commented on how hard those poor parents have to work to keep their shrieking youngsters’ bellies full. Often when we go into the barn during baby swallow time we can see the down covered little heads peering out of the mud nests, and when a parent arrives to rest on the edge of the nest, mouths open and screaming commences. As I mentioned above barn swallow parents sometimes get help from other birds to feed their young. These “helpers at the nest” are usually older siblings from previous clutches, but unrelated juveniles may help as well. This is an interesting example of how individuals in some species make a large sacrifice so that others of their kind can successfully raise their young.
After hatching, the helpless chicks remain in the nest for about 20 days, being fed compressed insect pellets by both their parents. Sometimes 400 trips per day are necessary to feed a single brood! Parents will continue to care for their young after they fledge (are able to fly), for about a week. Young barn swallows may remain in the area close to where they were born or travel to other colonies before migrating in the fall, joining their parents' flock. Although fewer eggs are laid during the first nesting season, young swallows are able to breed when they are about one year old.
When there is plenty of food available barn swallows can raise two clutches per year. This happened last year in our barn because we had a wet winter and spring and insect life was bountiful. This year it has been exceptionally dry and warm since November so I suspect our swallows may only raise one clutch.
Since the diet of barn swallows consists mostly of insects, they need to be long gone before cold weather arrives. By the middle of August most barn swallows start to head out. Hundreds of them can be seen on power lines flocking up for the long migration. At sunset, huge flocks of swallows descend into nearby marshes and wetlands to roost for the night. The sight of hundreds of birds diving into a marsh lead early Europeans to think that swallows spent the winter buried in marsh mud. It’s a pretty silly idea, but what else would you expect from a people who thought that the earth was flat!
At the first light of dawn the flock continues the long trip south. Covering several hundred miles a day, the swallows are focused on reaching their wintering grounds in South America. Some birds even fly across central America and island hop across the West Indies. The island hoppers get to spend the summer in humid, insect rich, Caribbean environments, but they are also at the mercy of the weather.
Though we welcome their arrival each spring, the presence of barn swallows has a bigger significance than our personal love of these cunning little birds. Barn swallows are an environmental indicator species (consider them cousins to the canary in the coalmine). Barn swallows give us clues as to the overall health of the environment because food availability and weather influence their migrations and populations.
I look forward to watching our guests raising their young on our farm, and hope that we have a bumper crop of screaming babies this year.
Art (top) by Wilhelm Goebel
Art (Left) by Marie Nestler-Laux
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