To the Editor:

For the 16th consecutive year, the Helderberg Escarpment Hawk Watch, affiliated with the Hawk Migration Association of North America and with the NorthEast Hawk Watch, has monitored and documented the annual migration of diurnal raptors (daytime birds of prey) through the greater Capital Region.

The Thacher Park Overlook west of Albany was originally selected as the site for this endeavor because of its scenic vista, offering panoramic views spanning from the northwest clockwise around to the southeast, as well as for its spacious paved parking area, offering convenient access to this yearly spectacle for hundreds of park patrons and raptor enthusiasts.

Each year, beginning in August and continuing on through December, various species of hawks and eagles in the north country vacate their summer breeding grounds and head south for their winter feeding grounds. Many variables contribute to the timing and distance of their movement and each species seems to add its own preferences and inclinations to the influences of seasonal weather and prey abundance. Some birds move a few hundred miles south while others may travel thousands of miles to distant historic grounds as far away as South America.

During such extended migrations, the conservation of energy is of utmost importance as the birds travel through unfamiliar territory and deal with weather systems and competing local birds along the way. Assisting them during their flight are atmospheric thermals, which are areas of warm air arising from heated land masses and acting as aerial escalators, allowing them to take advantage of the lift provided as that soar on their outstretched wings.

The altitude gained results in the ability to glide relatively effortlessly dozens of miles further along their course without having to resort to the labor-intensive, energy-consuming activity of constantly flapping their wings and significantly contributes to the difference between survival and failure. The Helderberg escarpment adds a unique aspect to the mix in favor of those birds who somehow appreciate the advantage to be gained from the additional lift generated by various winds when they interact with the escarpment cliffs and are deflected up hundreds if not thousands of feet.

Thirty-five years ago, on my first watch at this site, after three days of rain during central days in September — the historic peak of migration — I was blessed with an ideal northeasterly wind and clear skies. Mid-morning, about 250 broad-winged hawks (smaller relatives of our more common local red-tails) arose on the morning thermals as the rising sun heated the lands in the vicinity of the large industrial park below the escarpment.

With barely any movement of their outstretched wings, these birds floated in toward the notch between the overlook and the building across the chasm to the right at the Glen Doone picnic area. On set wings, they encountered the rising column of uplifting air and proceeded to take advantage of the lift to form a large cylinder of swirling creatures known to raptor enthusiasts as a kettle because of its similarity to the bubbles rising in a kettle of boiling water.

As if hanging motionless on invisible strings in a gigantic mobile, these long-distance travelers eked out every last bit of lift and elevation before streaming off, in a single file, gliding in a southwesterly direction in search of their next oasis of energy conservation on their way south. It was a truly magical first experience of this phenomena at this site.

The rest of the day was equally as exciting with over 900 birds passing over and taking advantage of the cliffs’ unique elevator ride. Until this year, I considered it the best day I’ve ever had at the hawk watch.

Each September, in addition to documenting the most concentrated influx of raptors through the region during the middle three days of the month (the 14th through the 16th), we educate park patrons about this annual free amazing event … .

Our modest watch at the overlook is fortunate when we have one hundred hours. We begin our observations annually on the weekend before the 15th of the month in order to identify local raptors and avoid double counting these birds. As the significance of this venue has evolved, we work to educate the people who are visiting the park about this annual event.

On the Saturday prior to the 15th, a festive activity is  held centered around local raptor expert Richele Ford and her collection of well-cared-for birds of prey. This year, her red-tailed hawk, her Harris’s hawk, and numerous owls (nocturnal raptors) thrilled upwards of 700 park patrons.

While she held her audience’s attention with her birds and her educational message about conservation and our interdependent roles in the environment, local birding experts Collen and Tom Williams from the Hudson Mohawk Bird Club along with local Audubon executive John Loz, Marian Sole of the Alan Devoe Bird Club in Columbia County, photographer and spotter Luciano Toffolo, and teacher Susan Breslin guided park patrons through the process of raptor spotting and identification. The combination of hundreds of rapt spectators and multiple kettles of almost 100 birds soaring over Richele during her talks created a day surpassing any other I’ve ever experienced at this site.

How fortunate we were to have our Thacher Park patron and director of the Emma Treadwell Nature Center, Nancy Engel, on hand to experience the thrill of the day’s first kettle. I think she’s hooked and already looking forward to next year’s event on Sept. 8, 2018.

This fall’s Helderberg Escarpment Hawk Watch spotted and identified a total of 1,118 birds, including: 26 black vultures, 40 turkey vultures, eight osprey, 17 bald eagles (each was a thrill and required a shout of “bald eagle” to alert everyone within earshot), six northern harriers, 12 sharp-shinned hawks, seven Cooper’s hawks, one red-shouldered hawk, 906 of our most abundant seasonal migrant — the broad-winged hawk, 21 red- tailed hawks, five American kestrels — our smallest falcon, three Merlins — a medium falcon, four Peregrine falcons, and 40 unidentified raptors of various species.

Not bad for 75 hours of scanning the skies. During that time, over 3,911 patrons visited the overlook and had the opportunity to enjoy the view. It's also noteworthy that one of the Emma Treadwell staff reported seeing over 1,000 raptors migrating over that center on from Sept. 14 through Sept. 16. As this appears to be the area where many birds are seen at a distance from the overlook, this may be a site worthy of future attention.

For more information about the ongoing migration, consult the Hudson Mohawk Bird Club at: www.HMBC.org, or the Capital Region Audubon Society at: www capitalregionaudubon.org. And for daily bird counts, contact the Cornell website at:  eBird.org

And keep looking up.

Will Aubrey

Helderberg Escarpment Hawk Watch