The hummingbirds that summer in Maine will soon be on their way to Central and South America. Before they go, consider these tiny, mighty creatures.
Around here, the most common species is the ruby-throated hummingbird, still occasionally seen stocking up on nectar to fuel the long flight south. All summer, they have been sticking their long beaks into flowers, feeders and, in one strange case, a local lobsterman’s nose until he batted it off.
Actually, the nectar is not their chief food. They need the sugar to power their flight in search of insects, their principal source of protein. Little was known about their consumption of bugs until a photographer with a high-speed camera looked into the matter. Shooting 200-500 frames per second, the device caught hummingbirds chasing insects, mouths wide open, until they caught the bugs and snapped their beaks shut.
Such cameras also can produce slow-motion films showing the birds, their wings beating up to 100 times a second as they hover in jerky moves from one point in the air to another or fight each other in their territorial zeal to monopolize a flower or feeder.
The Hilton Center in South Carolina sends “citizen scientists” to Costa Rica, El Salvador and Belize each winter to check on hummingbird migration. At last count, they had caught and banded 4,288 ruby throats, including some that had been banded a year before in the same spot.
No one knows how the birds seem to find their way back to the same places at the two ends of their semiannual journeys. They are understood to know how to fly north or south by focusing on Polaris, the North Star, the only star that appears to stay in place. As a backup, they are said to rely on bits of magnetite in their heads, which act as a compass.
Some advice if you have a feeder: Leave it up and full for at least three weeks after you see the last bird. Some may still be here and need another meal of nectar to fatten them up for the migration.