Hawk Watch


(This 5th Buffalo News column was first published on May 6 1991.)


      Just inside the east entrance of Lakeside Memorial Park in Hamburg a jogger passed a line of parked cars and a group of people sitting on lawn chairs looking up at the sky with binoculars.  He slowed to a stop and asked pleasantly, ³What are you folks doing?²


      One of the observers responded, ³We¹re looking at hawks.²


      The runner peered up briefly and, seeing nothing but blue sky and clouds, shook his head and jogged on.  I am certain that he thought that he had been caught by the old ³Look! Look!² trick.


      But as the jogger trotted down the road into the park, I was looking at a kettle of almost 100 hawks.  (Kettle is the term hawk watchers have adopted for such a group of hawks. It was chosen because the hawks appear like those tiny bubbles that move about in a seething pot just before it comes to a boil.)


      Even with my binoculars the hawks were tiny specks in the sky, perhaps a half mile overhead.  Some flew in line, others in slow circles, but all moved northeast toward the eastern end of Lake Erie.  There a few would swing to the west and would soon pass the hawk watching station at Grimsby; most would continue northeast and would be seen by hawk watchers at Braddock¹s Bay near Rochester and farther east at Oswego¹s Sandy Ponds lookout.  They would then continue north to breed in the vast forests of the Adirondacks and Canada.


      It was a quite remarkable experience to have so many hawks in one binocular field.  The tiny dots appeared like those no-see-ums that circle in front of your eyes in the summer woods.  When you looked down to rest your neck, it was very difficult to find them again.


      At this distance it took an expert like Roberta McDonald, who regularly reports the numbers of migrating raptors passing this location to the Hawk Migration Association of North America, to point out species to me.  Most were broad-winged hawks, less than half the size of our resident red-tails.  But soaring with the broad-wings on this late April morning were a few ospreys, those almost eagle-sized fish hawks, as well as turkey vultures, sharp-shinned hawks, and kestrels.  Nearer to us two Cooper¹s hawks that reside in the park woods flew with graceful wing beats, courting in slow circles part way up to the migrants.


      Over time rarer birds are seen from this vantage point as well.  This year, for example, both bald and golden eagles have been recorded here as have  goshawks, those fierce symbols of the wild north country.  Merlins will probably be seen later.


      Where we sat we could feel the wind blowing from the north off Lake Erie.  This would seem to oppose this flight; instead the light breeze contributed to the lift that helped the raptors soar.


      To see why, you need only recall from junior high school science three weather effects: (1) land changes temperature faster than water, (2) cold air flows toward warm, and (3) heated air rises.  On this sunny spring day, the lake remained much colder than the land to its south and the air cooled by the lake flowed inland toward the air heated by the land, thus creating the breeze we felt.  This onshore breeze drove a wedge under the warmer air, forcing that air upward in what are called thermals.  It was this rising air that provided the lift for the migrating hawks.


      In exactly the way hawks do, glider pilots utilize such thermals to maintain altitude or even to rise to higher levels.  In fact glider pilots often take cues from soaring hawks.


      On that day there was very little wind so the birds had to fly thousands of feet above us to take advantage of the thermals.  If there had been a wind out of the south of perhaps 10 to 20 miles per hour, what I have described would have taken effect at a much lower level and we would have been able to watch the birds just a few hundred feet overhead.


      Even the jogger would have seen them then.