THE MIRACLE OF MIGRATION, THE HAWK CLIFF STORY
William J. Rayner
Saturday, September 16, 1961, dawned cold and clear with winds out of the northwest at eight to ten miles per hour. All week long the weather had been unusually unsettled, the direct result of a tropical storm that had moved out of Texas bringing rain, high winds, and soaring temperatures to the Great Lakes region. By Friday, however, temperatures began falling as a strong pressure-system moved in behind the remnants of Hurricane Carla.
Thus, the stage was set for one of the greatest movement of hawks ever recorded in a single day at Hawk Cliff, Ontario, located just east of the fishing and resort village of Port Stanley, along the north shore of Lake Erie, midway between Buffalo and Detroit. By late afternoon weary groups of observers huddled around the chief compiler for the day, who announced the day’s totals, including an estimated 70,800 Broad-winged Hawks!
For years, Hawk Cliff has been regarded as one of the best observation points for viewing the fall hawk migration in North America. It is arguably the best known birdwatching location in Elgin County as well. Here, and at other major migration points such as Hawk Mountain in Pennsylvania, Hawk Ridge at Duluth, Minnesota, and Cape May, New Jersey, a strategic geographical formation coupled with an ideal topography produces an optimum viewing area.
Reluctant to cross any large body of water due to the absence of thermal currents, birds migrating south from Northern Ontario and Quebec are redirected in a southwesterly path the by the St. Lawrence and the north shore of Lakes Ontario and Erie. At the western end of Lake Ontario, many hawks turn south until they encounter Lake Erie.
Here once again they face open water and are rapidly forced northwestward along the Lake Erie shoreline from Long Point to the most northerly location on the lake near Hawk Cliff. The land rises abruptly to form cliffs one hundred feet high, and it is here that raptors can be observed in their greatest concentrations. It should be noted, however, that the approaching flight is often quite broad in scope, and the birds passing directly over Hawk Cliff are possibly just a small percentage of the entire migration aloft at any given time.
Access to the Cliff area is gained by a township road, which is an extension of Elgin County Road 22, running south from St. Thomas. Many local birders tend to make their observations at the end of this road where it terminates at the cliff’s edge, although it is often possible to obtain a better view of migration from points farther inland. Since the land on either side of the road is mostly agricultural, the view both to the east and west is unhindered, affording the visitor an excellent panorama of the encircling flights.
After passing the cliff, the flight path again widens as the shoreline turns southwestward towards Rondeau Provincial Park and Point Pelee National Park. Although some hawks may turn sooner at such points along the migration route as the Niagara River, Long Point, and Point Pelee, a vast majority move into the United States over the Lake St.Clair-Detroit River region where they join thousands of other migrants along the great Mississippi flyway.
In spring, the process is reversed when northward-flying hawks encounter the natural barrier of the Great Lakes and turn eastward following the south shore of Lake Erie and Lake Ontario.
The topography at the observation area tends to divide the migration into separate but sometimes overlapping flight paths. Falcons generally follow the shoreline where the open fields along the cliff’s edge provide hunting opportunities, particularly for American Kestrel. Accipiters, such as the Cooper’s and Sharp-shinned hawks, migrate in large numbers slightly inland, often along the edges of woodlands and wooded ravines, while buteos, such as Red-tailed and Broad-winged hawks, show considerable variation in their migration pattern depending on the wind direction and weather conditions from day to day.
Even though the Ontario migration tends to peak in volume about the middle of September with the passage of Broad-winged Hawks, American Kestrels and Northern Harriers can often be observed in early August, while Red-tailed Hawks fly well into December. In addition, Monarch Butterflies, Blue Jays, and Ruby-throated Hummingbirds stage spectacular fly-bys of their own, while rarities such as Swainson’s Hawk, Purple Sandpiper, Pomarine Jaeger, Western Kingbird and Yellow-throated Warbler provide additional excitement.
Of all the raptor migrants, the American Kestrel is the most common breeding hawk in southwestern Ontario, and its young can be seen feeding around Hawk Cliff in early August. Later in the month, the young are joined by other first-year kestrels, and the migration begins. With favorable weather, large numbers of Sharp-shins, harriers, and Broad-wings can be expected by the middle of September.
It is during this peak period each year that hundreds of visitors come to the cliff to view the spectacle, record their observations on film, renew old friendships, and make new acquaintances. A knowledgeable birder is always on the alert for the occasional Merlin or Osprey, while the sighting of a Peregrine Falcon or Bald Eagle generates waves of excitement throughout the crowd. By the first week of October most of the Broad-wings have passed through, and the numbers of Sharp-shins and kestrels begin to decline.
A variety of migrants soon follow, including Red-tailed and Red-shouldered hawks. To a large extent, these are immature birds and are the forerunners of the adult flights that occur in the latter part of October and into November and December. Abrupt weather changes induce the first flights of Cooper’s Hawk and Turkey Vultures, while the Northern Harrier continues to pass by throughout this period.
Golden Eagle sightings are often made during the latter stages of the migration, and adult Red-tails and Red-shoulders are sometimes joined by migrating Rough-legged Hawks from the far north. Northern Goshawk numbers during November fluctuate considerably from year to year; during the fall of 1973, a record total of sixty-three were observed. By December, only the adult Red-tails can be found in significant numbers. Observations made during December 1973 show a total of 839 Red-tails passing through, including 120 on December 24.
Buteos, in general, and the Broad-winged Hawks, in particular, often take advantage of specific weather conditions to assist them in migrating to their wintering grounds in Central and South America. Heat, reflected from the uneven patchwork landscape, begins to rise into the atmosphere in the form of “bubbles” or “pockets” of warm air called thermals.
Great numbers of hawks seek out these thermals; with outstretched wings, they form “cauldrons” or “kettles’ as they ascend, circling or “boiling up” until the warm air dissipates. At that point the birds begin to “peel off”, setting their wings in a “tuck” position for the long glide westward and downward, until another thermal lifts them and the process is repeated. By employing this unique system of travel, soaring hawks can migrate great distances while expending little energy.
The ornithological history of Hawk Cliff is as interesting as it is varied. Research indicates that the late
W. E. Saunders of London, Ontario, was probably the first to make fall migration observations here. For years Saunders had become increasingly aware of autumn flights passing west along the north shore of Lake Erie, but it wasn’t until 1931 that he recorded his first notes linking the cliffs east of Port Stanley with the migration itself.
Once he had pinpointed the observation area, he made many visits to Hawk Cliff to watch the drama unfold, even during the Second World War when travel was restricted. It was during these trips that Saunders eagerly noted the prevailing weather conditions, the great variety of species that could be observed, and the fluctuation from year to year.
In the years immediately following the war, interest in this autumn ritual was renewed by a number of local naturalists. They were determined to learn more about the complexities of this phenomenon through a more scientific approach than had been undertaken by Saunders and his contemporaries. By organizing large numbers of competent observers in a coordinated effort, it was hoped that raptor movements could be plotted over a large geographical area simultaneously, thereby removing much of the speculation and the inaccuracies that had previously surrounded the migration.
Although the early fall migration had been closely observed over the years, it was not until Canada’s Centennial Year that the most comprehensive study to date was undertaken. John R. Haugh, a graduate student of Cornell University in Ithaca, New York, came to Hawk Cliff to observe the fall migration as part of his doctoral studies. He made daily observations from September 11 to November 22, 1967, except when inclement weather prevented birds from migrating.
Haugh, whose previous studies had taken him to Alaska, the Yukon, and South America, proved to be a well-qualified and knowledgeable observer, and his findings are still being referred to today by local bird-watchers as a basis for comparing fluctuating raptor populations. Not only did his report support previous suspicions that the hawk migration carried well into the beginning of winter, but it also defined the relationship of one species to another over an extended period.
He accurately recorded the relative numbers of Red-shouldered Hawks passing through at a rate of approximately one for every four Red-tailed Hawks observed. Until then, only occasional sightings of Red-shoulders had been reported, giving rise to speculation that this striking woodland bird had been passing through either unnoticed or simply misidentified.
As an active participant in many of the well-coordinated “hawkwatches” along the north shore of Lake Erie during the 1950s and 1960s, Marshall Field, a local bird authority in St. Thomas, often viewed these immense flights and wondered how one might lure these diurnal raptors down for capture and banding. With the aid and encouragement of John Roberts, who was operating the banding program at Point Pelee, and Bill Wasserfall, of the Ontario Bird Banding Association, plans were laid for establishing a banding station at Hawk Cliff.
In the spring of 1969, Field traveled to Derby Hill, New York, on the southeast tip of Lake Ontario, where Jim Grier and Stan Temple from Cornell University were operating a hawk trapping station. At this excellent spring migration point, Field was able to examine the various methods used for capturing birds of prey.
Later that summer, permission from the property owner was obtained, and on Labor Day weekend, the actual construction commenced on the first banding cabin at Hawk Cliff. Soon the eight-by-sixteen foot building was operational, but before long, Marshall Field and his small group of assistants ran into difficulties, due in part to the inexperience of the novice banders as well as the inefficiency of some of the hurriedly constructed trapping equipment. Both Field and his friend, Bob Hubert, also of St. Thomas, had had a great deal of experience banding ducks over the years, but they soon learned that luring birds of prey into low slung mist nets was a far cry from scattering some cracked corn at the entrance to a duck trap.
The banders ceased operations that year on October 15 with a total of 202 raptors banded; they were a bit disillusioned but now had some valuable experience behind them. During the next several years, significant improvements were made to much of the equipment, the banders became much more proficient, and the number of stations grew to five.
In 1972, over one thousand raptors were banded, including the first Merlin and Golden Eagle. The following year another station was established, and the yearly total boasted a young gray-phased Gyrfalcon trapped and banded on December 15. The numbers of banded birds continued to grow each year, culminating in 1975 when 4,276 birds were processed at Hawk Cliff, nearly doubling the previous year’s total. Since then, yearly totals have leveled off somewhat, and there are now seven permanent banding locations erected on the lands of three property owners. At the conclusion of the 1992 banding season, a grand total of 55,993 raptors had been banded, representing twelve different species. By the end of the 2002 banding season, 78,536 had been banded with an annual seasonal average of 2,789 birds trapped each year since 1992 (representing one of the most productive locations for hawk banding anywhere in North America).
In recent years, members of the St. Thomas Field Naturalist Club, the Hawk Cliff Foundation and the Hawk Cliff Raptor Banding Station have combined their efforts and, along with assistance from the Ontario Ministry of Natural Resources, to host two hawk-viewing weekends in mid-September. Once each morning and afternoon, weather permitting, one or two members of the Banding Station present a “hawk talk” while displaying some of the birds caught and banded that day. At other times during the weekend, club members circulate throughout the crowd answering questions and distributing color pamphlets that describe Hawk Cliff and the raptors.
For many years, the St. Thomas Field Naturalists counted hawks at the Cliff and combined their results with the Hawk Cliff Raptor Banding Station in order to get a better picture of migration patterns. People like the Grant and Marge Bowlby and Harvey and Janet Patterson were regular fixtures along Hawk Cliff Road, vigilantly counting the passing flow of raptors.
Since 1995, the Hawk Cliff Foundation, a group dedicated to educating the public on the annual hawk migration and seeking to provide more permanent access for hawk-watching enthusiasts to Hawk Cliff, has kept track of observation results and organized volunteers to perform daily migration counts. Please see the tables at the end of this essay for a list of their observation results by month and by species from 1995 to 2002. This data has been submitted to the Hawk Migration Association of North American (HMANA) Raptors Online database for inclusion with data from other major hawk watch locations from across the continent. Enthusiastic counters like Tom Bolohan, Ross Tucker, Barry Cherriere, Keith Sealey, Sue Ross and Shay Redmond have lead this program and provide valuable education about the hawk migration to the hundreds of visitors each fall to the Cliff.
The spectacle of thousands of Broad-winged Hawks “kettling” overhead draws people from all over Ontario and the northern United States hoping to “hit the big day!” Bus loads of binocular-equipped, camera-toting birders arrive, swelling the weekend crowds; during the week, school buses bring eager-eyed children to view the array of migrants. Over the years these magnificent birds of prey have captivated both the young and the young-in-heart.
In the tradition of Point Pelee, Rondeau, and Long Point in springtime, Lake Erie’s unique geographical configuration ensures that each autumn another miracle of migration will come to pass for all to enjoy in the skies over Hawk Cliff.
[Most of this article was originally published as a “Birding Hot Spots” feature in the October 1993 issue of Birder’s World, but it has subsequently been modified and updated for inclusion here.]
Hawk Cliff Raptor Bander Results 1969-2002
Another account of the first 25 years written by Marshall Field can be found on the last five pages of the 1993 HRBC Newsletter – 25th Anniversary