Around the Island

Mashomack Musings: Swarms of swallows

Lawns are faded, but the evening insect chorus is louder than ever. It’s still summer, but the sun is setting noticeably earlier.

Change is in the air.

Birds and other critters have noticed these subtle differences earlier than we have. Osprey are sometimes still found on their nests, but for the most part they’re fishing and flying, exercising those wings for the long flight south.

Tree swallows have also finished up their breeding season. Abandoning their territorial nature, they’re gathering in flocks, sometimes numbering thousands.

Traveling in large groups may help protect them from predators, and the older birds can lead the younger on their first migration. They travel during the day, resting in large, eye-catching groups at night.

This annual gathering is mesmerizing. Hundreds may gather on wires or soar through the air above Mashomack’s fields. About an hour before sunset, the group will swirl above a chosen roosting site like an avian tornado. With each pass, a few drop into the roost, until all are settled for the night. 

Swallows normally feed on insects, gleaning mosquitoes and other flying bugs, but now they’re also gorging themselves on fruits. Bayberries are a favorite, fueling them for migration.

Populations here in the East head south to Florida, or even Central America. Normally they hug the coast, stopping in marshes and fields to fuel up.

Studies dating back to the 1960s show they are sensitive to climate and have begun laying eggs earlier in the year.

As the swallows wing south, we bid adieu. As fall begins in earnest, nestboxes are cleaned out, making them ready for the swallows’ welcome return in April.