Hawk Watchers Score High Marks
This autumn, the hawk watchers at Illinois Beach State Park in Zion counted more raptors than in the three previous autumns combined, tallying 14,690 as of mid-November. "This season ... has been absolutely amazing!" says Vic Berardi, the coordinator of the Illinois Beach Hawk Watch.
Broad-winged hawks lead the field. The numbers of these fall migrants in the past three years ranged from 39 to 424. In 2003, an astonishing 9,553 "broadies" cruised past the ecstatic spotters. "They kept streaming by, one by one, then by the hundreds," says veteran hawk watcher Eric Delbecq. "We all had big grins on our faces."
Rick Schmude, a relatively new hawk watcher, says that the broad-wingeds reminded him of World War II movies where endless squadrons of planes fly by.
"It was one of the most amazing things I've ever seen," he says.
Merlins and rough-legged hawks were also seen in record numbers this fall. Since this was only the station's fourth season, birders say that it is too soon to know if the high numbers indicate any trends.
Predicting numbers of migrating hawks is never a sure bet, but weather often provides clues. From September through November, Berardi spends 30 to 60 minutes a night studying weather patterns on the Internet to determine how many watchers to send out each day. In the second half of September, when the "broadies" were due, Berardi says, "We were getting a very strong westerly flow of air. ... Those west winds typically move the birds closer to the lakefront." Hawks generally fly through Chicago Wilderness about 15 miles west of Lake Michigan. They ride thermals (rising columns of warm air) to gain altitude. Strong west winds this year caused these thermals to angle east toward the lakeshore.
During fall migration, broad-winged hawks spend about a month migrating from their breeding grounds in Canada and the northern American states down to South America. "There isn't another hawk watch south of Illinois Beach State Park until you get to Texas," says Berardi. "Geographically, we're in a fantastic location for the study of hawk migration."
Check Hawks in the Sky for the final figures for all 16 species of raptors counted.
— Betsy J. Green
