Migrating birds of prey – eagles, hawks, falcons and owls – pass through Canyon Country on their way south. Some species may travel to southern Arizona and New Mexico; others will cross the U.S. border and head to Mexico, Central America or even South America. Many of these birds come from the western interior of North America, from high desert plains and montane woodlands, boreal forests or the barren Arctic tundra. Of course, some of the local individuals stick around throughwinter, and are joined by some of these migrants.
Fall migration for raptors and songbirds occurs at a more leisurely pace than springmigration. In spring birds are moving north to establish breeding territories, mate and raise young. They are focused on this northbound movement, utilizing fat reserves to push themselves to their breeding grounds.
Hawkwatch International monitors a site on the GoshuteMountains in eastern Nevada, close to Utah-Nevada border. Here birds funnel along the western edge of the Great Salt Lake, then hit the updrafts along the first range they encounter – the Goshutes. In 2010 over 16,000 birds comprising 19 species were recorded during the fall migration. That averaged out to about 23 raptors an hour, almost aneed forair-trafficcontrol.
When migrating the birds use thermals, updraftsand leading lines (mountain ridges or coastlines) to facilitatetravel. The birds may utilize strong winds on the leading edge of a northern cold front to cover vast distances and stay out of the storm’s fury.
Hawks and eagles and songbirds pass through the La Sals on a migration route, as well. Perhaps the birds follow the edge of the Book Cliffs or take advantage of desert thermals to cover open expanses of the Cisco Desert en route to the mountains. Perhaps then drift along Three Step Mesa and use updrafts off of Montezuma Canyon to help propel them south towards the San Juan River. At least I would like to think so, as I imagine these birds cruising over the canyons and mesas.
Two locations I have watched raptors stream by are Bull Canyon and Bald Mesa. Bull Canyon funnels birds along thewestern canyon rim of FisherValley and offers a great vantage pointdue to the sheer cliffs. Even low-flying sharp-shinned or Cooper’s hawks can be spotted here before they start to circle and climb out of the canyon.
Bald Mesa, along the road to Warner Lake, is less defined than Bull Canyon. Here one has to hope for west winds and keep a sharp eye out for birds hugging the base of Gold Knob. One advantage to this site is as the birds pass by, they are cast against an open sky allowing for identification. This location has proven good for migrating warblers, perhaps an indicator that their predators are using a different route.
So one can only hope for favorable winds, clear skies and an opportunity to sit and watch for this passing October spectacle. Just don’t expect numbers like the Goshutes, but the thrill of seeing these migrating birds is just as rewarding.