Northern Harrier

Circus cyaneus
Range Map

We used to call the Northern Harrier the “Marsh Hawk”, an appropriate moniker I believe. We usually find them performing lazy passes, and sailing over grassy fields and wetlands. When they sense an opportunity, they will drop to the ground and overpower any prey they can. More often, their prey is small rodents or birds, but they will take down larger prey, such as coots (often by drowning) if the harrier can pull it off.

Between Summer and Winter these raptors will range over most of the North American continent’s wetlands and grass fields. Some Northern Harriers will migrate in spring as far north as Canada and Alaska, and retreat south in winter, ranging from the USA and south through Mexico, Central America and barely into Colombia. At North America’s mid-latitudes, they may remain year-round.

Males may take up to five mates in a season, a practice known as polygyny, which is rare among raptors. Color can usually differentiate males and females. The girls are more brown, while the boys are more silvery and even whitish. Science views Northern Harriers as monotypic (i.e. no subspecies).

These hawks have owl-like faces. Their ear holes are larger than most hawks, and their disc-like faces have stiff feathers that funnel sounds into their ears, which allows them to find unseen prey. I’ve visited many of the western USA states, and I’ve met Northern Harriers in most of them. At Heron Flats in Aransas NWR Texas, I observed these birds foraging over the deep grass marshes and pouncing from the air into the thick grass and brush. I can only assume it was an example of hunting by ear. It would be very unlikely that a sense of sight gave away any prey’s position.

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