During the autumn months, the lower Detroit River (MI) becomes a corridor for the passage of migratory birds, and has gained international recognition for the annual volume of birds of prey. Hundreds of thousands of migrating hawks, eagles, falcons, and vultures are concentrated at this location where it is possible to systematically count them each year. A standardized monitoring program is conducted by the U.S. Fish and Wildlife Service (USFWS), the Detroit River International Wildlife Refuge (DRIWR) and its friends group, the International Wildlife Refuge Alliance (IWRA).
Broad-winged Hawks (Buteo platypterus) concentrate at the lower Detroit River each September after nesting in deciduous or mixed-deciduous forests of Ontario. They will continue until they reach their wintering areas in northern South America. . Photo credits: Rodney Laura (left) and Jerry Jourdan (right).
Calendar of Hawk Movement
Broad-winged Hawks (Buteo platypterus) concentrate at the lower Detroit River each September after nesting in deciduous or mixed-deciduous forests of Ontario. They will continue until they reach their wintering areas in northern South America. . Photo credits: Rodney Laura (left) and Jerry Jourdan (right).
Videos courtesy of Mark Wloch
Broadwing Hawks 17 Sept 2009
Turkey Vultures 10 Oct 2010
Calendar of Hawk Movement
(click on image for larger version)
Figure 1. Seasonal distributions of raptors through the Detroit River Hawk Watch site between 01 September and 30 November. Results based on 3-day running average of count data collected between 1991 - 2008.

