Romance or Predation?

By early March, many permanent avian residents of the American Midwest have already paired off for the breeding season; some, like geese and raptors, are monogamous (at least for the season) while others are not.  Among the most conspicuous of these early spring couples are bald eagles, Canada geese, red-tailed hawks and mourning doves.

Yesterday, a less common pair of residents strafed our Columbia neighborhood.  Zig-zagging through the trees, the powerful hunters moved in tandem, apparently searching for unwary songbirds; their broad wings, medium size and long, rounded tails revealed that they were Cooper's hawks, among our more aggressive raptors.  I wondered if they were engaged in cooperative hunting or if I was witnessing a courtship display.

In either case, the male must proceed with caution, lest romance or cooperation end in disaster.  Known to prefer larger prey such as flickers, pigeons, kestrels and sharp-shinned hawks, Cooper's hawks may even kill members of their own species; indeed, female Cooper's hawks, significantly larger than their male counterparts, are usually the aggressors.