KEMPTON – Fans of rock 'n roll icon Steve Miller who traveled to Musikfest in Bethlehem earlier this week were not disappointed as he performed most of his signature songs, including "Fly Like An Eagle."

For fans of the annual Autumn Hawk Watch at Hawk Mountain Sanctuary, located atop the Blue Mountain between Drehersville and Kempton, all indications are for another satisfying season of viewing raptors from the trails and lookouts. Already several huge birds of prey have been spotted in the skies overhead, even though the watch's official beginning is Monday, Aug. 15.

Billed as "Nature's Greatest Airshow," hawks, eagles, falcons and other birds have been spotted from the North Lookout. This year's watch will be held daily, depending on weather conditions, through Thursday, Dec. 15.

"This is a great time to visit Hawk Mountain, even for those who know nothing about birds," sanctuary president Jerry Regan said. "Our trained staff and interns spot approaching birds, point out where to look, and identify what you're seeing, making it fun and easy."

Over the next four months, an average 18,000 birds of prey will soar over the rocky North Lookout, a 1,500-foot outcropping on the Kittatinny Ridge of the Blue Mountain. Many fly past at eye-level, and some people travel great distances from as far away as New England and south of the Mason-Dixon Line.

"Last year was a phenomenal season," Regan said. "Our naturalists counted 20,496 raptors, including a record 406 bald eagles, and we're hoping for a repeat."

For migrants, timing is everything, and different species migrate at predictable times, and passing through in late summer are ospreys, bald eagles, hummingbirds and monarch butterflies. In early mornings, colorful songbirds pass in waves on their own migration, and this also is the last chance to enjoy the still-green, but subtly changing Appalachian Mountain views and balmy weather.

In mid-September, broad-winged hawk numbers build, and these small, round-winged hawks fly in large flocks and gain altitude in circling thermals, or rising columns of air, before gliding by gracefully. Observers with lucky timing can spot hundreds of broadwings in an afternoon, as was the case last year on September 16 when counters recorded 1,282 broad-winged hawks before rain and fog set in.

By mid-October, northwest winds bring the greatest species diversity and fall foliage is at its peak. During prime conditions, visitors can get good views of as many as 16 different species – including red-tailed, red-shouldered, rough-legged, sharp-shinned and Cooper's hawks, northern harriers, peregrine falcons, and merlins.

In November, the migration begins to ebb, but this is when hawk watchers can expect to see golden eagles and northern goshawks. By December, the skies have emptied, but the North Lookout draws visitors seeking solitude and an occasional bald eagle.

Raptor migration is an age-old phenomenon, as they have followed the Appalachian Mountains southward for thousands of years. Weather determines how many birds will pass, with the best flights following a cold front, when northwest winds prevail, with fewer birds tend to be seen when the air is hot and still.

Birds of prey also use pockets of warm, rising air called "thermals" to fuel their long distance journeys. Thermals allow birds of prey to ascend quickly to thousands of feet and then glide in the direction of their destination.

Thermals are not present over water, so migrating birds hug the Appalachian Mountains, and grab what amounts to a "free ride" by soaring south on this energy-saving, migration highway. Best of all, there is no need to walk a great distance to see this annual air show, as the first scenic overlook is just 100 yards from the parking area at the sanctuary.

For visitors with limited mobility, an all-terrain wheelchair is available at the Visitor Center. A golf cart is usually available on autumn weekends, but calling ahead to check on available is recommended.

For information about the Autumn Hawk Watch and Hawk Mountain Sanctuary, call the visitor center at 610-756-6961 or visit the website at www.hawkmountain.org.