Naturalist’s Notebook: Northern Harrier Attack

9 December 1991 Calif. San Luis Obispo Co., Carrizo Plains

I observe a Northern Harrier attack small birds over open grasslands in an unconventional manner.

I’ve observed harriers attempt capture of small birds many times in the past, but in this instance the method of attack was like none I’d observed before. Instead of the typical buoyant low quartering and lightning pounce, this young male harrier launches its attack from its perch in the low grass and crosses almost 100 yds in an impressive turn of speed. The final attack is a sudden slashing down through the grass, causing an explosion of small birds from the grass. But it misses and vaults skyward, wheels, and executes another sprint low over the grass for 20 or 30 feet before again slashing down and again scattering small birds from the grass. It fails in this second attack and again vaults sharply up, then turning out, flies away in the typical buoyant patroling flight.

The wings are angled and pointed like a falcon’s during the sprint.

Set of wings during glide interval.

The wings flicked powerfully and rapidly during the sprint and appeared distinctly falcon-like. A gentle undulation to the flight was imparted by interspersed brief glide intervals with the wings pulled in close to the body and wrists pressed slightly out and the primaries swept back.

A male in its first adult plumage, this bird is heavily marked through the underparts, and with warm browns and dark streaks blending with the more adult male grays over the head and neck.

N. J. Schmitt