BY SCOTT RANDO
With September here, along with some cooler mornings, a few bird species have started to migrate south. Smaller birds, such as the yellow warbler, were already on their way near the end of August, and some might have seen nighthawks snatching insects in flight over lakes and rivers as they too headed south.
Raptors—hawks, falcons, eagles, etc.—are easier to notice, because they are larger birds. They also tend to fly near ridges along the Appalachian chain that runs up and down the eastern part of the country.
When the wind blows from the northwest, raptors take advantage of both the tailwinds and the lift generated by the air moving upslope on the windward side of the ridges. These conditions enable raptors to conserve energy as they fly south.
One of the first species of raptors to be seen at the favorite hawk-watching sites is the broad-winged hawk. These members of the Buteo genus can sometimes be mistaken for red-tailed hawks.
Broad-winged hawks have barred tails (black-on-white), and a black fringe is frequently visible around the wings. These hawks pass through our region within a short period of time. The best time to see large numbers of hawks is around the middle of September, when several hundred can be spotted in a single day.
Using satellite tracking of telemetered birds, scientists have determined that the average broad-wing hawk migrates 4,370 miles to northern South America.
There are other species that migrate in September. Osprey migration peaks during this time, with 10 or more birds being seen per day when the winds are favorable. Merlins and kestrels, smaller raptors in the falcon family, can also be spotted during this time. Sometimes there are interactions between species; this frequently leads to impromptu airshows.
These species of raptors are seen early when the weather is still mild; a lot of migrating monarch butterflies move through during this time. If you don’t like the cold, September and early October are good times for hawk-watching. Other species—bald and golden eagles, for example—come through during October and November.
To learn the timing of various raptor-species migrations, check out hawkcount.org/.
Comments
No comments on this item Please log in to comment by clicking here