PAXSON -- Mosquitoes aren't my favorite animal. I recognize that they are necessary and important part of our ecosystem, but if they need to suck blood, does it have to itch? What's the point?
Conversely, I like swallows. They eat a lot of mosquitoes.
Our business at Maclaren River is located next to the highway bridge. The bridge is home to a couple hundred cliff swallow nests occupied by nearly 500 swallows. The birds create a mosquito-free zone almost a quarter-mile in diameter. There are very few flies around the bridge either. Our sled dogs and our horse also appreciate the swallows' diligence in keeping the flying insects to a manageable level.
Their preference for winged insects make swallows welcome almost everywhere. There are a half dozen types of swallows in Alaska. The common ones are cliff, bank, violet-green and tree swallows. There are also some barn swallows, mostly in Southeast and along the Kenai Penisula, as well as a very few rough-winged swallows in the southern reaches of the Panhandle.
Tree swallows and violet-green swallows look quite similar and are the birds that commonly nest in birdhouses and holes in older buildings. They will nest in small mixed colonies if there are enough suitable nesting sites. When I was a kid I spent a fair amount of time building birdhouses to attract swallows to our yard. Our family kept chickens so there was also unending supply of feathers for the birds to use as nest materials.
Bank swallows don't use nesting boxes but also benefit from human activity. Gravel pits and other types of excavations that leave sandy cliffs are prime nesting locations. Away from towns they dig holes in cutbanks along rivers and melting peat banks. Along the Denali Highway are several pingos that host small bank swallow colonies.
The swallow that makes the biggest dent in insect populations in these parts is the cliff swallow. These birds can nest in colonies of several thousand given the right conditions. The largest group of swallows I'm personally aware of is on the middle Porcupine River, where the cliffs of impressive Howling Dog Canyon host at least 4,000 swallows.
I once spent half a day idling my small skiff under the rock walls trying to count nests without getting pooped on.
Ravens and gulls prey heavily on cliff swallows by knocking down the mud nests to eat eggs and hatchlings. Because many swallow communities occur over water, young swallows must come out of the nest flying. But predators have learned to knock the youngsters into the water on their first flight from the nest, and the toll of initial predation can amount to more than half of the nestlings.
One might think that cliff swallow could be wiped out soon, but protection has evolved with the Porcupine River swallow collectives safeguarded by Peregrine falcons. Peregrines eat swallows, of course, but they take far fewer than the gulls. In return for a few adult swallows, the falcons keep the other predatory birds at bay.
The big swallow colony near the Maclaren Glacier is guarded in the same way by a gyrfalcon aerie. The area below the aerie is littered with swallow remains, but there is no raven predation whatsoever on nests in that location.
In fact, predator exploitation isn't the main reproduction obstacle facing Alaska swallows. Weather is their deadliest killer. Swallows spend more time on the wing than any other songbird. This requires an immense intake of energy. A spell of cold rainy weather, lasting as little as four days, can cause significant mortality. If insects don't fly, swallows can't eat. Only tree swallows take a percentage of their food from the ground.
A good mosquito crop -- the same hatch that makes me scratch -- keeps our swallows happy.
John Schandelmeier is a lifelong Alaskan who lives with his family near Paxson. He is a Bristol Bay commercial fisherman and two-time winner of the Yukon Quest International Sled Dog Race.