Jeff Green | Apr 13, 2006
Back toHomeNature Reflections - April 13, 2006
Aboil of Hawks
by Jean Griffin
A Boil of Hawks
Early next month, if you are fortunate, you may see one or two Broad-winged Hawks in our area, but not in any large number. There may be a pair in the mixed forest west of Ardoch, or another pair south of Poland, or one or two may be seen soaring as they search for food, or perched on a tree. Since these gentle, retiring hawks prefer deciduous forests where they search for prey they are seldom seen in open country except during migration. So imagine the scene I saw recently on my trip to Texas - thousands!
The day was ripe for hawk migration - sunny, and reasonably warm, sending thermals into the air which were perfect for the hawks to help them lift from their overnight roosts in the mesquite and other trees, and then giving them the ability to move with the winds once they had reached a suitable height.
That one day we estimated we saw over six thousand Broad-winged Hawks - in ‘boils’ or ‘kettles’ as they set out on another day’s journey to the north. That particular day was only another for the hawks in their journey north. And as night fell the hawks too fell into the shelter of the trees for rest and protection. The next day, out early, we saw first one, then several, as they lifted off for a repeat of the previous day, though we did not see as many boils or kettles.
Where had these birds come from? From South and Central America , where they had spent the winter months, waiting for the proper time to migrate to their breeding areas. There they had fed, rested, and prepared for the migration by increasing their body weight with stored fat to have the necessary endurance for the long flight to the northern forests where breeding would take place.
Hawks do not like to make long flights over water, so they funnel up the Central Americas and into Texas , and since the urge to migrate and breed is the same for each species and comes at the appropriate time, they tend to congregate in these amazing numbers. From Texas the broad-wings will follow their usual migration routes, with many following the Mississippi Valley northward fanning out as they near their breeding grounds with some ending where we can occasionally see or hear them as pairs settle in their particular territory to court, mate, build nests and raise young. These flyways are followed year after year and on favourable flying days (those with westerly winds and thermals) the birds may be flying so high they are almost out of sight.
Broad-winged Hawks tend to migrate later than other hawk species and are among the first to depart in autumn, when again they can sometimes be seen in large, loose flocks. That day in Texas there were other birds migrating as well - Turkey Vultures, some other hawk species in much smaller numbers, even a flock of Anhingas, but the Broad-winged Hawks were the ones putting on the magnificent display.