Lakes
As the raptors move south from their eastern Canadian breeding grounds, they are blocked by the north shore of Lakes Erie and Ontario. Thermals do not form over water so the birds are forced in one of two directions: east around Lake Ontario or west around Lake Erie. Those that move west follow the north shore of Lake Erie, until they reach the mouth of the Detroit River. Turning back is not an option so they are forced to cross the 4-mile span to southeast Michigan, specifically Lake Erie Metropark and Pointe Mouillee State Game Area. They loose altitude as they cross the water, making it easier for them to be observed.

Thermals
Many species of raptors utilize thermals to varying degrees during migration. Thermals are columns of rising air caused by heating of the earth by the sun. A bird will soar and gain altitude in a thermal, set its wings, and glide to the next thermal using little energy.

Weather
Weather is a key influence on hawk migration. During the autumn months, cold fronts descend from the north. After these fronts pass through the region, a series of weather events fall into place:

Light winds with a north component
Clearer skies
Increasing barometric pressure
Decreasing humidity

These factors combine to provide ideal weather for hawk migration. Once the cold front passes, it may be minutes, hours, or days, before large flights can be seen.

For those most interested in viewing sheer numbers, September is the month to visit. Broad-winged Hawks pass through by the tens of thousands. The second and third week are the most productive, with the peak centering on September 19th.

Swainson's Hawks are expected as well. Osprey and Bald Eagles are seen almost daily (whether or not they are counted varies: check our protocols.). The majority of migrant Sharp-shinned Hawks and American Kestrels are also seen in September.

The pace shifts in October. Huge numbers are unlikely, but the variation in species increases. Red-shouldered Hawks, more Red-tailed Hawks and more Cooper's Hawks are observed. Peregrines peak the first week, while Turkey Vultures are highest the second week (thousands in one day). On two occasions, both in October, all 16 regularly occurring species have been recorded

By November, species diversity is low, but Golden Eagles, Northern Goshawks and Rough-legged Hawks make the chilly days worthwhile.

Sites for hawk observation shift due to changes in wind speed and direction. The following is a guide to help direct you to the correct site.

Lake Erie Metropark Boat Launch: used with west, northwest, north, northeast, east, and southwest winds.

Pointe Mouillee State Game Area Headquarters: used with northwest, north, and strong northeast winds.

The vast majority of hours logged by SMRR are from the LEMP Boat Launch. If in doubt, check there first.

If you have a scope, bring it, but you'll want binoculars, too. Dress appropriately. Large temperature swings in a day are possible. In September, heat and humidity can get high. Conversely, November's cold winds and snow flurries can be bone chilling. Comfortable shoes make standing for hours more bearable, but a lawn chair is even better. Parking is available at both watch sites. Heated restrooms are available at LEMP boat launch; unheated at PMSGA. There are no food concessions at either site. Although local restaurants are within driving distance, birds are notorious for ignoring the lunchtime lull! A sack lunch with a thermos, hat, bug spray and sunscreen are all good ideas.