Ferruginous Hawks are exceptionally hard to see in Minnesota. They're a raptor species that favors open grassland. This is a landform that once covered vast areas of the state. Today, half of Minnesota's total land mass is devoted to corn and soybeans. Our grassland remnants are tiny, and the number of acres devoted to crops grows day by day

(In the Aug. 6 issue of the StarTrib, reporter Josephine Marcotty had an excellent story explaining the issue, which is conversion of grassland, almost any marginal land, to crops.)

Ferruginous Hawks are easier to find in South Dakota, so far. The conversion there of grassland and even native prairie is no less of a problem.

On a recent trip west Jude and I saw no raptor species other than Ferruginous during a 200-mile drive through the expansive rolling short-grass prairie of eastern Wyoming. Given the habit, the birds are there. Profiles of Ferruginous Hawks state plainly that the bird simply avoids cropland. This largest of North American hawks feeds on mammals from jackrabbit size down. You won't find jackrabbits in a cornfield.

The study discussed in Ms. Marcotty's article found 37,000 square miles of mid-American grassland, wetland, and scrublands – bird habitat -- were plowed up and planted to crops in the past four years. In Minnesota, between 2008 and 2011, 2,000 square miles of were lost. The provisions of federal farm legislation and its crop-insurance program make it profitable for farmers to plant even marginal land. Land marginal for crops could be called natural habitat – grasslands, marshes, field edges, the shallow ditches between plowed land and a road. Little as that's been, it's better than having the nothing we seem to be approaching.

Red-tailed Hawks are found throughout North America except for its Arctic edges. The species ranges well into Mexico as well. While it breeds in the grasslands where Ferruginous Hawks are found, Red-tails prefer open areas with a mix of trees. They obviously find our metro highway/Interstate landscape to their liking.

This interested me because of that Ferruginous-heavy day in Wyoming: one nesting family of two adults and three chicks, plus six sightings of lone hawks. I haven't kept track of the number of sightings in South Dakota. We don't see this species on every visit, though. I have one Minnesota sighting, years ago near Brown's Valley on Minnesota's far western border. There's a line of hills following the north-south route of a state highway there. The hills push westerly winds into superior soaring opportunities for raptors. That's where I got lucky.

Luck is what you need for Ferruginous Hawks. In a growing portion of Minnesota, where corn and beans stretch forever, luck helps with Red-tails, too. There is no sign that's going to get better.