September 23, 2006 – Hallowell, Maine
A few nights ago, a river of birds streamed over my head, over my little town in Maine, over Portland, and Boston and New York. I stood out on my porch in the dark, the low rumbles of trucks on the highway faintly audible, and listened upwards to the sounds of thrushes filling the air–perhaps 300-400 birds per hour passing over by my estimation.
Most of the birds were Swainson’s Thrushes giving their spring peeper-like ‘pwee’ nocturnal call-notes. Swainsonï¿½s Thrushes are a bird of the Borealï¿½an estimated 73% of their entire population breeds in the Boreal forest of Canada and Alaska.
Swainson’s Thrushes, like most birds, migrate at night. Most people don’t know that. I’m one of the lucky ones who do and because of that I listened as this river of birds flowed from the Boreal forest of Canada, south through Maine on their way to Central and South America.
It’s just over a month since I was in the Boreal, in the Mackenzie Valley of the Northwest Territories. Some of the Swainsonï¿½s Thrushes I heard overhead a few nights ago might well have raised young or been born in the Mackenzie Valley. I can imagine their songs spiraling into the air from behind the community center in Deline in June or floating across Frame Lake in Yellowknife. It seems almost miraculous that on most fall nights in the eastern U.S., you can stand outside at night, listen up into the dark sky, and hear for yourself the moving current of migrating birds that link us with the Boreal.