“Hawk watching is a little different,” said Jim Zeman of Bucksport as he sat amid a small hawk-watching crowd on Cadillac Mountain. “Most people that are birdwatchers are not hawk watchers. You sit in one place for four or eight hours and just watch whatever comes through.”
It was sunny Tuesday. The official hawk migration season on Mount Desert Island began Sunday.
“It’s an obsession,” said park volunteer Joe Ferrara. “By the time the eight weeks are up, everyone’s going to have sore butts, necks, shoulders and eye strain.”
“You’re excited about seeing these tiny dots in the sky,” said Marion Mogielnicki of Sullivan, who sat beside Zeman. “It’s inexplicable.”
A hawk is a raptor, a bird of prey with a hooked beak and talons to snatch up its meal.
Led by Acadia National Park Interpretive Ranger Angi King Johnston, the hawk-watching group faced east and scanned the horizon. They used Bar Island, the Porcupine Islands, Ironbound Island, Dorr Mountain and Schoodic Head as reference points.
They were on the lookout for 12 different species of raptors: the bald eagle, northern harrier, turkey vulture, American kestrel, northern goshawk, osprey, peregrine falcon, broad-winged hawk, red-tailed hawk, sharp-shinned hawk, Cooper’s hawk and red-shouldered hawk.
“From the general shape of the bird we are able to see if it’s a raptor,” said Johnston. “The silhouette will tell us what group it belongs to.”
If the bird flies close enough, finer details such as tail shape, coloration and markings can reveal the species.
Johnston of Seal Harbor has been involved in the hawk watch for nine years, but this is her first year as the “official raptor ranger,” which means she watches for hawks on Cadillac Mountain four days a week from 9 a.m. to 2 p.m. during migration season.
On the flat, lichen-speckled rocks near the summit of the mountain on the North Ridge Trail, she educates those who join her and brings a crate of binoculars for the unprepared.
A sharp-shinned Hawk flew around the mountain to the group’s left.
“They’re not slowing down for much,” said Johnston. “And they aren’t about to turn around and fight the wind.
“These birds are very energy efficient birds. They’re only going to fly when the conditions are right. We could probably learn something from them.”
Before they take flight, migrating hawks wait for three things: a north wind, thermals and low humidity.
Thermals — columns of rising hot air — are escalators for hawks. They occur when sun heats granite mountaintops, as well as buildings and parking lots. Thermals allow birds to use less energy to gain altitude. They ride the hot air by flying in circles, up and up.
Johnston records different aspects of the weather with a yellow, handheld gadget called a Kestrel Weather Meter. At noon, the humidity was 70 percent, it was 65 degrees and the wind was blowing 10 mph on average.
Between 9 and 10 a.m. that morning, the wind blew north and the hawk watchers counted 24 birds. But the wind turned east as the day progressed.
“It’s amazing how the slightest shift from a north to an east wind will change the amount of birds that are seen by 50 percent,” said Johnston.
The highlight of the morning was a juvenile eagle taking the migration path. Many eagles tend to stay year-round, but some travel to southern New England, Johnston said.
The migrating hawks that fly over Cadillac Mountain come from northern Maine and eastern Canada, Johnston said.
Many migrating birds use the coastline as a map. Instead of flying over open water, birds hug the coast so they can easily find food during the day and shelter at night.
“They need gas stations, just as we do when we’re traveling,” said Johnston.
They migrate to the southern U.S., South America and the Caribbean. The distance they must travel will determine when they start off.
Hawk migration peaks in mid-September.
“We may easily see 300 birds a day [then],” said Johnston.
The migration season ends mid-October.
“I’ve been up here when snow was falling and the birds were still flying,” said Zeman.
“You’re a die-hard,” said Mogielnicki.
He laughed as he ate a sandwich and leaned back in a collapsible chair.
A broad-winged hawk flew by to the right, barely visible to the naked eye. To spot it, hawk watchers used the clouds as reference points.
“If there’s a chance of birds, I will most likely come up,” said Zeman, who attends the hawk watch on Cadillac three or four times a week.
He has been birding as a hobby for 20 years. When the temperature drops later in the migratory season, he parks a third of the way down the mountain and watches the hawks from his car.
Johnston calls the hawk watch on Cadillac Mountain “good community science.”
More than 300 sites report their hawk numbers to a national database. The statistics help researchers determine how hawks migrate and population trends.
“We hope to notice any problems before they become bigger problems, such as endangerment,” said Johnston.
A sharp-shinned hawk appeared above Ironbound Island and flew into a gorge below, not reaching a high enough altitude to make it over Cadillac Mountain, the highest point on the Eastern Seaboard.
“He’s thinking it’s time to eat. He’s tired of fighting the winds,” said Johnston.
By 1 p.m., the group had spotted 41 hawks of nine different species.
“Up until now, we had seen only 11 birds. My goal was to double that number today, and we’ve quadrupled it almost,” Johnston said.
Two turkey vultures zigzagged in front of the group, rising and falling with the wind.
During the final hour of the watch, fewer hawks appeared. An M-shaped shadow wavered across the rocks, and all the hawk watchers quickly looked to the sky — all except Johnston.
“I can tell it’s a gull by the shadow,” she said as she lifted her binoculars and looked toward the Porcupine Islands.