03/22/2026
Next week is the biggest raptor migration passage of the year. And it happens directly over your commute.
Between March 28 and April 10, the Broad-winged Hawk migration reaches its annual peak along the Appalachian Ridge system and the Atlantic Coast flyway. On peak days at major hawk watch sites, counters record 10,000-30,000 raptors in a single afternoon. The one-day record at Hawk Mountain, Pennsylvania: 21,488 Broad-winged Hawks on September 14, 2006 (fall migration). The spring record: 11,247 in a single day.
The spring passage is earlier and more compressed than fall. 80% of the annual Broad-winged Hawk migration passes through the eastern US in a 14-day window centered on early April. That window opens THIS WEEKEND.
WHAT TO EXPECT:
THE KETTLES: Broad-winged Hawks are the ONLY eastern raptor that migrates in flocks. They stack into thermal columns ā spiraling upward in a tight spiral, then gliding downhill to the next thermal. A single kettle can contain 200-5,000 birds at altitudes from 500 to 6,000 feet. At 6,000 feet, they're visible as specks. At 1,000 feet, you can see individual wing shapes. At 500 feet ā which happens when thermals are weak ā they're close enough to hear their wing beats.
THE MIX: Broad-wingeds dominate (85-90% of the count), but riding with them: Sharp-shinned Hawks, Cooper's Hawks, Red-tailed Hawks, Red-shouldered Hawks, Ospreys, and occasional Bald Eagles. Each species has a distinctive flight shape ā learning 3-4 shapes lets you identify species from half a mile:
- Broad-winged: compact, stubby wings, short tail. Looks like a flying barrel.
- Sharp-shinned: tiny, flap-flap-glide rhythm, long tail.
- Cooper's: larger than sharp-shin, slower wingbeats, rounder tail tip.
- Red-tailed: large, broad wings, obvious dark belly band, rufous tail.
HOW TO SEE THEM (anywhere in the eastern US):
1. Pick a day with light SW wind and puffy cumulus clouds (cumulus = thermals = hawks).
2. Find a south-facing hilltop, rooftop, or open field between 11 AM and 3 PM.
3. Face south-southwest. The hawks travel NE, riding thermals that develop over south-facing slopes.
4. Scan the base of cumulus clouds ā kettles form where warm air rises. One speck becomes 50 in 5 minutes.
5. Bring binoculars. The big kettles are visible to the naked eye, but individual species ID requires 8-10Ć magnification.
Peak days: Look for the first warm day after a cold front passes ā the high pressure behind a cold front produces the clear, sunny, thermal-rich conditions that generate the biggest kettle days. A warm day after 2-3 cool days = go outside at noon.
You drive under this migration every spring. The hawks have been passing over your commute since March. You just never looked up.
Next week, look up.