Return of the Raptors

Return of the raptors

A guide to the great hawk migration

by Mark Stabb


From a clifftop high above the town of Grimsby, the CN Tower is a toothpick on the northern horizon across Lake Ontario. Below this Niagara Escarpment ridge, vehicles hum along the Queen Elizabeth Way (QEW) like toy cars. Then, on an updraft of wind, less than 30 metres away and appearing almost larger than life, a red-shouldered hawk flies by, soon followed by another, then three turkey vultures, then a red-tailed hawk and, later, an early Cooper’s hawk. On yet another Easter weekend at Beamer Memorial Conservation Area, one of my favourite hawk-watching sites, the annual northerly parade of raptors is building and will soon be in full flight.


1 Accipiters
Accipiters have relatively short, rounded wings and long, narrow tails, making these birds agile when pursuing flying prey. They include sharpshinned hawk (blue jay sized), Cooper’s hawk (crow sized) and northern goshawk (raven sized).

2 Falcons
Falcons are streamlined with long, pointed wings and narrow tails. They include the American kestrel (robin sized), merlin (blue jay sized), peregrine falcon (crow sized) and the larger, rarely seen, gyrfalcon.

3 Harriers
Northern harriers have dark “hoods,” long tails, a white patch on the rump and long, narrow wings. These birds glide with wings held in a slight V shape (dihedral).

4 Buteos
Buteos have long, wide wings adapted for soaring, and relatively short tails. They include broad-winged hawk and red-shouldered hawk (both crow sized), red-tailed hawk (raven sized) and rough-legged hawk (similar body size to red-tailed with longer wings and tail).

5 Ospreys
Ospreys have white patches on the body and long, narrow wings, also with white patches, which look crooked in flight.

6 Turkey Vultures
Turkey vultures are large dark birds with long wings. Like the harrier, this species holds its wings in a dihedral when soaring.

7 Eagles
Eagles are large birds with long, wide wings that they hold straight out in flight. The bald eagle, at maturity, has a bright white head and tail and a dark brown body. The golden eagle, at maturity, has a dark body; immature birds have white patches on their tail and wings.

The first step in identifying raptors is to get to know the shapes and body sizes the various species take in flight. Add to this some knowledge of typical behaviour and field marks, and you can start identifying species of migrating hawks. By visiting a hawk-watch site, you can pick up more tips from the masters, who, during lulls in the action, are more than willing to help out beginners.

At the first hint of spring, thousands of avian surfers – hawks and their raptor relatives known for their killing talons and hooked beaks – ride waves of air north across the continent, travelling from their winter haunts in the southern U.S. and South and Central America to nesting grounds in Ontario and points as far north as the tundra. At the Great Lakes, this impressive mass migration funnels along escarpments, cliffs and ridges, where the birds catch thermals that build over the earth’s warming surface and avoid large bodies of water, above which such updrafts form less readily. On a really good day at Beamer, you can see up to 1,500 raptors – the sheer numbers make hawk watching one of the most spectacular and accessible of all bird-watching activities.

Every year, a new crop of naturalists discovers this extraordinary show. Enthusiasts line key migration sites to watch the birds stream by, and what a striking performance they give! Strong and swift, these raptors – predators that seize and carry away prey – include falcons, buteos, accipiters, ospreys, harriers, eagles, vultures and owls. All but night-travelling owls channel north during the day and, lucky for us, at most civilized bird-watching hours, between 10 a.m. and 4 p.m., when thermals are at their peak.
Arrival time

Ontario field ornithologist Ron Pittaway is a hawk-watching devotee who never misses a spring outing. “My first experience was actually at Derby Hill in New York,” says Pittaway. “Some Syracuse birders visiting Ontario told me about it decades ago, and I went there the following spring. Luckily I arrived on a day when the hawks were just streaming through. I’ve gone back for years.” On a peak day, spring hawk watchers might see 2,000–4,000 or more raptors at Derby Hill.

Pittaway has visited most hawk-watching sites in Ontario and has a few tips for watchers taking in the air show for the first time. “People should check weather conditions and websites before they go,” he says, pointing out that the parade of predators is tracked on the website of the Hawk Migration Association of North America (HMANA). Created in 1974 to help promote raptor conservation, mainly through research and education programs, HMANA has helped turn hawk watching into both a mainstream and technically sophisticated activity. The website ( provides charts to help plan an outing.

Says Pittaway: “The best spring viewing takes place immediately before and during the passage of a front from the south with gentle south winds.” The best flights at Derby Hill arrive with southeast winds.

As these large predators are energy conservation specialists, they follow predictable spring migration routes that minimize their need to refuel and enable them to “surf ” thermals that build over warming land masses. With wings fixed, the birds swirl upward until the rising air dissipates and sends them soaring to the bottom of the next rising pocket of air. Thermals are strongest during the day and do not develop well over water, so raptors arriving from the south “pile up” against the shores of lakes Erie and Ontario. To avoid the cold, thermal-free waters, the birds make their way around the lakes, either past Grimsby in the west – best viewed at Beamer Memorial Conservation Area – or past Derby Hill, at the southeast corner of Lake Ontario.

Ontario Nature executive director Caroline Schultz describes the spring aerial display as a “great activity” for just about anyone. “People bring along their lawn chairs and pack a lunch and Thermos. You can see all kinds of people at a place like Grimsby on a given spring day, and there are usually lots of people ready to help with identification. It’s particularly exciting to see kids and novice birders coming out to see this spectacle.”

The main spring migration spans March to May, with species such as red-tailed hawks and turkey vultures reaching the Great Lakes in early March. Red-shouldered hawks peak in late March, while broad-winged hawks concentrate their flights almost exclusively in late April and early May.

Throughout this period, certain birds have predictable peak times of day for migrating. For instance, sharp-shinned hawks, Cooper’s hawks and goshawks – all more inclined than more passive surfers to wing along on their own steam – power through in the morning, and then their numbers drop off as the day progresses and the raptors go bird-hunting.

Pittaway says adult breeding birds of each species are the first to arrive back in the spring, with the juvenile birds following later. Despite their long journeys, he adds that the hawks, with the odd exception, are in generally good condition in the spring.

Best Hawk-watching Guidebooks
Great guides for beginners include Field Guide to Hawks, by William S. Clark and Brian K. Wheeler (Houghton Mifflin, 2nd ed., 2001); Hawks and Owls of the Great Lakes Region and Eastern North America, by Chris Earley (Firefly Books, 2004); Hawks, edited by Peter Dunne (Peterson Flash Guide Series, Houghton Mifflin, 1996); and Guide to Hawk Watching in North America, by Donald Heintzelman (Globe Pequot Press, 2nd ed., 2004). Advanced watchers might check out Hawks from Every Angle: How to Identify Raptors in Flight, by Jerry Liguori (Princeton University Press, 2005); A Photographic Guide to North American Raptors, by Brian K. Wheeler and William S. Clark (Academic Press, 2003); and, for reading at home, Hawks in Flight, by Peter Dunne, David Sibley and Clay Sutton (Houghton Mifflin, 1988).


Once you have observed this spring ritual, you will almost certainly return for the fall migration, an even more spectacular event in Ontario. Not only are the raptors more smartly attired with fresh feathers after their once-a-year summer moult, but they funnel through southern Ontario in even more spectacular numbers, to wind along the north shores of the lakes before heading toward the United States and points south. Prime viewing spots include Cranberry Marsh in Whitby, High Park in Toronto and Hawk Cliff south of St. Thomas. Numbers swell as the birds converge at Point Pelee and at Holiday Beach farther west, where up to 100,000 hawks have been seen in one season.

The best fall viewing conditions are the opposite of those in the spring, says David Brown, a volunteer and observer with the Hawk Cliff Foundation. “Large movements often follow a strong cold front with north and northwesterly winds that carry birds to the Great Lakes, where they pile up and follow the shorelines southwest.”

In fall, broad-winged hawks have the most concentrated migrations. These birds are no more socially interactive than other raptors, but they group together out of convenience – the easiest way for one to find the next thermal is to follow another broad-wing. Seeing these swirling concentrations, called “kettles,” sometimes with several thousand of birds trailing each other in one day, has turned many a naturalist into a lifelong hawk watcher.

Eagles, with a wingspan that can approach two and a half metres, are especially memorable to see in either season but are best known for their late October or early November flights. On November 1, 2008, watchers at Hawk Cliff experienced what may have been a once-in-a-lifetime thrill – a record 65 golden eagles passed the site. Brown was lucky enough to see the exceptional concentration of this rare northern breeder. “It was amazing,” he says. “At one point we averaged a golden every five minutes or so.”

Ideal viewing conditions in either season are cooler days with overcast skies. The birds are easier to see against clouds rather than blue sky are closer to the ground, as the thermals lifting the birds are weaker. Rain, snow or fog generally means minimal flights, though a few stalwart hawk watchers visit their posts in almost all weather conditions. I have a particularly fond memory of the late Bruce Duncan – one of Ontario’s pioneer hawk watchers – materializing from the rainy mist at Hawk Cliff to knock on my fogged-up car window and show me a peregrine falcon he had banded that morning.


  1. Janet Sauve Janet Sauve
    February 22, 2012    

    Apparently Ospreys should not arrive in Guelph, Ont. for another 2 months, but I was expecting them much earlier. I was checking your web site for that info, but found it interesting anyway. Thanks.

  2. April 13, 2013    

    I live in St.Thomas, Ontario close to Hawks Cliff. For the last four years I,ve visited a local park an average of six days a week to feed the squirrels. My husband has Alzheimer,s and this time in the park by myself is my respite. I,ve studied the wildlife in the park, both birds and mammals. I was treated last fall by a flock of around 50 Blue Jays stopping in the park on their migration. I throw peanuts in the shell for the squirrels and soon I had six or seven around my car at one time competing with the group of eighteen squirrels that come daily. One of the Jays gave a strange unfamiliar call and the squirrels left fast. I learned on the internet that Jays can mimic sounds like their cousins the crows and if anything is threatening their food source they use it to scare them off. In this case the call of a Red Tail hawk. Learning this brought the revelation why over the years there were days I never saw a squirrel but I had spotted a large bird soaring around up and down hardly ever flapping it,s wings. Today is April 13 2013 and somewhere around three weeks ago a large flock of big dark birds came over and across the park, it was an impressive sight. I never saw the flock again but three of them decided to stay and the days they were covering the park the squirrels were absent. I never thought of looking into them until one of my squirrels disappeared.. He had been coming to the car to sit by my door and eat cookies since I first came. He was an older squirrel and two years ago he showed up one day with three quarters of his tail skinned off. It eventually dried up and left him with just a stub. Last year he suffered another calamity and lost s few of his toes and one ear. He never moved very fast after that and this winter he would come out and sit a few feet away from a tree to let me know where he was,it was a different spot everyday because the other younger squirrels knew I gave him tiny butter tarts and would take them away from him.. Then after the three stayed behind he just never came again. I cruised around the park every day for over a week looking for him because it probably sounds off the wall but the squirrel and I had a strong bond. How off the wall would it be to think that one day as he traveled across the park finding a spot to wait for me that one of those three birds made off with him. I see the birders every fall with their chairs and Tim Horton,s coffee sitting along the side roads close to Hawks Cliff binoculars either in their laps or in use scanning the sky. I always thought when the Hawks were migrating they may have went in pairs but never imagined they flew together in large numbers.
    What I,d like to know is why the birders are only there in the fall, could this huge flock I saw in the park a few weeks ago be Red Tails, we even have a golf club in the area called Redtail, and if they could make off with an animal the size of a squirrel. If this is the case I have an unfavorable opinion of them because I fear for my other friends. I,ve been watching these birds closely ever since, the time of day I see them, the pattern they soar around the park and how closely they stay together. I,ve visited a lot of websites trying to learn what I can about them and yours is the best I,ve found. Thank you for the information on the different raptors in my area. Valerie Wells. Sorry I went on so long about this.

  3. September 19, 2014    

    Thanks for sharing your thoughts. I truly appreciate your efforts annd I am waiting for your further write ups thank you once again.

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