A beginning birder looks at hawk-watching the way a Texan looks at lobster: “What do I do with this thing?” Take my advice. Get the lobster roll. All the work is done for you.
Likewise, at the Acadia Hawk Watch, all the work is done for you. This year’s watch began on Tuesday, and will continue into November. Experts volunteer time every morning to identify the raptors passing the summit of Cadillac Mountain in Acadia National Park.
Hawk identification is intimidating. Every raptor starts out as a speck on the horizon, yet the experts can figure out what each one is, while it’s still miles away. How?
It’s not as hard as it looks. There are about 34 diurnal raptors in North America, but fewer than half of them migrate through Maine. We’re only dealing with 15 species up there, and roughly 70 percent of the migrants seen last year were just three species.
Three.
Unlike songbird recognition, color and field marks aren’t that important in hawk identification. The hawks sort themselves out, first by size, then by flight style.
The big species are easy. Eagles, ospreys, and vultures are much larger than the other raptors. Bald eagles fly with their wings out straight. Turkey vultures fly with their wings in a deep V shape, teetering a lot. Ospreys have a unique gull-like wing shape, bent downward at the elbow.
Through binoculars, you can see the differences five miles away.
The northern harrier is a large hawk with long wings and tail. It’s built for slow gliding flights over marshes and fields. Around 100 harriers pass the summit every autumn.
The smaller hawks belong to one of three families: buteos, accipiters and falcons. Each family has a distinctive flight style, making identification easier.
Buteos have relatively broad wings and short tails. The broad-winged hawk is the smallest of these three, and it’s the hawk seen most often in Maine. The red-tailed hawk is the largest, while the red-shouldered hawk is midsize between the two.
All three buteos pass the Cadillac summit, but most are broad-winged hawks. Last year, only two red-shouldered hawks were counted.
Buteos hunt primarily from perches, waiting for a meal to scuttle by.
Accipiters are built for speed and agility. They have narrow wings and long tails, enabling them to chase their prey, typically small songbirds, through the forest.
Sharp-shinned hawks are common in Maine, and they strongly resemble the slightly larger, less common Cooper’s hawk. Northern goshawks are the largest accipiters in Maine. Last fall, 707 sharp-shinned hawks passed the Cadillac summit, but only eight Cooper’s hawks and one northern goshawk were tallied.
Falcons are built purely for speed. When diving, the peregrine falcon can hit 200 mph, making it the fastest creature on earth.
Merlins are smaller; American kestrels are the smallest. All have short, pointed wings and relatively short tails. The kestrels dominate the tally on Cadillac during fall migration, accounting for 78 percent of the falcons passing by.
Thus, even though hawk identification looks complicated, it’s not. The big ones are easy. The smaller ones fall into three families, but only a single species dominates each category during migration.
It doesn’t take long to recognize the identification clues as the raptors pass the summit, especially when experts are on hand to help.
Furthermore, the flight style of each family differs from the others, recognizable a mile away.
With their broad wings, buteos are typically observed soaring, circling and gliding. Narrower wings and longer tails make accipiters look like a flying cross overhead. Their flap-flap-flap-glide flight style is distinctive.
All falcons are built like jet fighters, but each species has its own flight style. Only the peregrine falcon soars. Merlins flap steadily toward wherever they’re going. No messing around. American kestrels are agile enough to hunt dragonflies. Their nimbleness gives them a fluttery look in flight.
It’s easier to identify a passing raptor at the Acadia Hawk Watch than it is to actually get there.
Reservations are now required to drive the Cadillac auto road, and typically require several days’ advance notice. That’s tricky.
Migrating hawks prefer tailwinds, and the best viewing happens on days with a northwest breeze and no fog. I watch the forecast a week ahead, pick the best day, and hope for the best.
Most hawk flights begin after 9 a.m. They taper off in the afternoon. The heaviest migration occurs in mid-September.
If you can learn how to eat a lobster, you can certainly learn how to identify a hawk.
