Editor’s note: Full-length version of story.
It was 8:10 on a mild, clear October 2009 morning on Metinic Island in Penobscot Bay, and a group of University of Maine researchers was already several hours into a shift collecting, banding and analyzing songbirds migrating off the Maine coast.
Rebecca Holberton, one of the nation’s top bird biologists, had arrived several days earlier, joining UMaine graduate student Adrienne Leppold, who oversees banding operations on Metinic and is a key member of Holberton’s Laboratory of Avian Biology. Leppold had already been on the island several weeks, going through a daily routine that included waking up before dawn, setting up nets, capturing birds, taking measurements, and banding the leg of each before release, doing visual surveys of birds landing on the island, and then retreating to a small cabin to analyze data and repeat the process the next day.
That morning, Leppold was busy banding under a tent when Holberton called to her to come outside. Leppold left the tent, looking down as usual to carefully tiptoe through throngs of birds amassed on the ground.
Look up, Holberton told her. What Leppold saw was shocking and thrilling at the same time – multiple flocks each made up of hundreds of birds moving west-southwest over the island. One flock of about 150 yellow-rumped warblers stopped and hovered briefly over the treetops west of the banding tent before splitting, with half the flock coming down to land in the trees and the other half continuing on.
“I could almost feel them thinking. It was a moving experience,” Leppold says, recalling the moment. “Most of these birds are nocturnal migrants, and this was 8:10 a.m. And there was the same insanity on the ground around us. Up until that point I hadn’t noticed such movements, but I also wasn’t really looking, as banding demands on-the-ground attention. I think at that moment was when it hit me that this was something huge.”
Huge, indeed. What Holberton noted visually that morning, and what Leppold was able to substantiate while conducting research on Metinic Island, was that the Gulf of Maine serves as a sort of superhighway for songbirds migrating between Canada and South America. It was a major find not only for Holberton’s lab, but also for an international effort to document the movements of migrating songbirds in the Gulf of Maine.
The Northeast Regional Migration Monitoring Network, a cooperative of Canadian and U.S. nonprofit organizations, government agencies and university researchers such as Holberton and her research team, has spent the last two years trying to determine how migrating species use the Gulf of Maine’s complex network of islands and coastal areas. Using a combination of decades-old monitoring techniques and newer technologies, Network researchers are examining migratory movements made by both large groups of birds and individuals.
“We’re combining techniques and technology for tracking small birds,” Holberton says. “With the monitoring network and the sites all over the Gulf of Maine, we can couple all these approaches across scales.”
Image Description: Songbird Superhighway