Birds are odd. Migrants bust into the state in spring, full of song and exuberant courtship. In autumn, they slip away quietly. This is already happening.
Even though southbound birds tend to be quiet and less boisterous, there are nonetheless some epic flights.
Shorebird migration is peaking in Maine right now. It will continue apace until Labor Day, then taper off throughout September. This is the best time of year to check coastal mudflats, preferably on a falling tide. A falling tide strands food on the mud for shorebirds. When the rising tide covers the banquet table, they head off to roost, awaiting the next tide.
Many different shorebird species come together on the mudflats, but they didn’t start out together. Each species has its own breeding zone in northern Canada. It’s coincidence when they arrive together. Shorebirds migrating farther tend to arrive later. Even though there’s a good mix of species on the mudflat on any single visit, it’s worth several return trips to greet the new arrivals.
Swallows depart early, typically forming into huge flocks that could put a swarm of locusts to shame. A thousand swallows can be in a single flock, cartwheeling through the air. They move through and disappear quickly, so this phenomenon is seldom seen. But when you see it, wow!
Common nighthawks also migrate in large groups, most of them around this time in August. On any evening when winds are favorable, you may become aware of dozens zigzagging south, perhaps hundreds. Most of the season, they’re noisy. But during migration flights, they’re oddly silent. They seem to enjoy flying along roadways, likely taking advantage of a warm pavement that provides uplift and attracts flying insects. On that, I’m just guessing.
Hawks provide the next migration spectacle. The trickle begins in late August and migration peaks in mid-September. American kestrels, sharp-shinned hawks and broad-winged hawks are the most numerous migrants through Maine. Ospreys, eagles and vultures soar by in smaller numbers.
A smattering of northern harriers, Cooper’s hawks, peregrine falcons and merlins also pass the summits. Red-tailed hawks migrate last, if at all. Many are just relocating for the winter, often along the interstate.
The most famous hawk watch in Maine takes place atop Cadillac Mountain in Acadia National Park, beginning in late August and persisting to November. Anyone can show up to join the fun. Experts are on hand to help. The daily count starts at 9 a.m. and typically continues to about 2 p.m.
On a good migration day, hawk-watchers are likely to linger longer. More than 100 hawks may pass the summit on a good morning. Up to 300 hawks fly by on a great day.
You can plan ahead for a great day. Moderate breezes from the northwest, typically after a cold front passes, make for ideal hawk-watching. You can often identify the best days to go by watching the forecast. Careful trip planning is especially important nowadays, because Acadia requires prepaid reservations to drive up the auto road.
As autumn waxes and hawks wane, another epic phenomenon occurs at Schoodic Point. Seabirds migrating southward from their breeding grounds in Canada follow the coastline. Schoodic Point juts far enough into the ocean that seabirds are forced to move around it. Tens of thousands of birds pass this spot every year, and the Sea Watch at Schoodic Point is there to count them.
It’s difficult to monitor seabirds in their remote nesting areas. By counting different species as they pass, Schoodic Institute biologists can estimate their breeding success and population trends.
The Sea Watch count starts every morning at sunrise and generally ends by 9 a.m., canceling for rain. Anyone can show up and join the count for free. Good binoculars are necessary, and a spotting scope is useful, as the huge flocks can be quite distant. They tend to be closer on winds blowing from the south and east. Winds from the north and west tend to push them farther offshore.
The last migration wave is lazy. Canada geese fly south to open water in winter, but at a leisurely pace. They often linger in Aroostook County until weather forces them to move. Their migratory flocks contain occasional rarities, including greater white-fronted and cackling geese, normally found in North America’s central states and provinces. Pink-footed and barnacle geese are Arctic breeders, from Greenland across northern Europe. When rare geese show up, they can draw a crowd.
There’s lots to see during fall migration, but you must work for it.
