Welcome the Swallows Back!

— by Sadie Bailey —

The lovely, amazing, migratory, mosquito-eating, beneficial swallows are back! They provide hours of entertainment with their aerial acrobabics. There are many species of swallows; all eat insect pests. Most North American species migrate from South America, some flying over 7,000 miles each way on their migration routes!

American Cliff Swallows breed in large colonies. They build conical mud nests and lay 3-6 eggs. The natural nest sites are on cliffs, preferably beneath overhangs, but as with the Eurasian House Martin, man-made structures are now the principal locations for breeding.

Please do not destroy swallows nests. Swallows protect mankind by eating disease-carrying mosquitoes and other insect pests. It is a federal offense under the 1918 Migratory Bird Act to pressure-wash or remove sitting swallows’ nests. As soon as they are done building, they are “sitting” the nest and have likely already laid eggs. The only time it is non-harming and legal to remove a swallow’s nest is within the first few days when they are building, or after nestlings have fledged and the swallows have left; generally, late September. In good years, swallows sometimes raise two clutches.

The major threat to swallow populations is Man. Destruction of nests, destruction of boreal forests and wetlands, and Light Pollution are all man-made threats causing loss of habitat.

Light Pollution kills night-flying migratory birds. The confused birds drop from exhaustion while flying in light beams, and if they don’t die from the fall, they are eaten by predators. Other threats are late winter storms, drought, and the ubiquitous year-round House Sparrow, which pushes out the swallows and claims their nests.

Things you can do to encourage swallow populations:
1) build swallow ledges, or tack cardboard to your decking and exterior wall under the nest, then toss the cardboard with the droppings after the nestlings have fledged.
2) Stop using upward facing, exposed, high-beam or spotlights. All light sources should be covered, downward facing, mounted as low as possible with the lowest wattage and lumen light bulbs possible.