This week’s Bird of the Week, compliments of the Weminuche Audubon Society and Audubon Rockies, is the northern harrier.
When hunting, the northern harrier, or marsh hawk, flies low to the ground with flaps and glides, often holding its wings in an upright V-shaped pattern. Its owl-like facial disk and stiff facial feathers direct sound to its large ear openings. This raptor often hears prey before seeing it. It may log up to 100 miles per day back and forth across its territory in search of food. Strictly carnivorous, the harrier prefers to eat small mammals, frogs, lizards, large insects and small songbirds, but will switch to larger prey when these are scarce.
Food availability is a driving force in reproduction. When prey is abundant in spring, the male harrier may mate with up to five females. During nesting, the male provides most of the food for the females and chicks, often in an aerial pass to his mate as he approaches the hidden ground nest.
Male northern harriers are gray above and whitish below. Females, which are larger and can weigh 50 percent more, are brown with streaked white undersides. The darker brown juvenile has a russet-colored breast. All have long, broad wings; long, darkbanded tails; and a characteristic white rump patch that is an identifying mark.
These raptors are still fairly common, but numbers are declining due to loss of open and wetland habitats and a decrease in prey. The juvenile harrier in this photograph showed up for the recent Christmas Bird Count in the open land near the Riverwalk.
For information on local bird-watching events, visit www.weminucheaudubon.org and www.facebook.com/weminucheaudubon/.