Twelve years of counting raptors during fall migration near Boise, Idaho, yielded 214 Broad-winged and 9 Red-shouldered Hawks, revealing these species as much more frequent in Idaho than previously known. The Broad-winged Hawk is an uncommon, annual fall migrant in Idaho. The Red-shouldered Hawk is at least casual, possibly nearly annual, during fall migration. These data match increased sightings from other western states that have likely resulted from a combination of increased observer coverage and possible range expansions and/or numerical increases for both species in the West.
Available at: http://works.bepress.com/jay_carlisle/12/