Hawk Migration

As leaves start to change and the cool crisp winds signal fall is coming, don’t forget to look up past the foliage.



‘Whoo-whooo’ is that in the sky?

Fall is the time when Broadwing Hawks create “kettles,” upward spiraling flocks that use hot air to gain altitude.  Sometimes dozens of birds will be in a kettle, the highest ones looking as small as specks of pepper.

Broadwing Hawks and other raptors use Vermont as their summer nesting grounds. Their fall migrations journey is on average 4,500 miles and takes 9 weeks. Lucky for Burlington residence, we are near one of the best sites for watching these birds as they start their long migration to South America. Historically, Mount Philo, Charlotte is one of the best places to watch hawks migrate. Mt. Philo holds the record for the most hawks seen in one day in Vermont (3,688).



One can see hawks migrating along the Champlain Valley flyway from late August until early December although the peak time is the second and third week in September. Experts are even starting to see them now! The best conditions to see the hawk migration are days that are clear, partially sunny, when the weather system switches from low pressure to high pressure causing wind to blow from the north. On a day like this, you can see up to 1,000 hawks in migration. The best time of day to see the hawks is between 11am and 2pm. Even on the peak days of migration, hawk hunters still find themselves waiting around to see hawks. The hawks usually come in spurts, with a lot of quiet waiting, and then a rush of excitement that naturalist Bryan Pfeiffer calls “a blizzard of Broadwings.”


8531371786_9204c26e03_z(Photo courtesy of flickr/afagen)


If you are unable to climb mount Philo the road is still open in September.  Some avid hawk watchers stay in the parking lot for unobstructed views of the hawks. We hope to see many people out on Mount Philo enjoying this natural phenomenon!



  • Bryan Pfeiffer
  • Alicia Daniel
  • Birdwatching in Vermont by Bryan Pfeiffer and Ted Murin
  • Photos courtesy of Bryan Pfeiffer