Early migrants of fall
Fall has just arrived, and with it comes the start of the fall migration for many birds. Some people have already noticed that the hummingbirds started getting sparse earlier in September, and common nighthawks were over places like the Delaware River in the early evening as they captured insects on the fly as they traveled south during late August. Some raptors also start their migration this month; a few kestrel and osprey have been spotted at various counting sites. Different species of raptors start their migration at different times of the fall, but the big move that is going on right now is predominantly broad-winged hawks.
Broad-winged hawks are unique among raptors in that when they migrate, they tend to travel together, en masse. They take advantage of wind and lift, as other raptors do, and travel in streams of birds that may stretch for miles. When a rising thermal is found, the stream will enter it and circle to catch lift and gain altitude. When numbers of hawks enter this column of rising air, this is called a “kettle”. Hundreds of broad-winged hawks may be in this kettle, and the vertical column of birds may span several hundred feet of altitude.
The peak time to see them in our region is around the third week of September; historically, the peak has occurred at Sunrise Mountain, NJ between the 20th and the 25th. Broad-winged hawks and other raptors like to take advantage of ridgelines for lift in order to save energy for their long trip, and Sunrise Mountain, located in Stokes State Forest, is a favored location.
Speaking of long trips, where are all these broad-winged hawks going? The hawks that are passing our area now will be in the northern portion of South America by October. As I write this, I checked some telemetry data from Hawk Mountain Sanctuary in PA. A female broad-winged hawk with a nesting territory in the Allegheny National Forest in PA was already in eastern Texas on the 19th of this month. Past telemetry data shows that “Patty” winters in northern Peru. Follow her journey here: https://www.hawkmountain.org/birdtracker.