Northern Harrier Hawk - Marsh Hawk

One day in the Moab, Utah sloughs, I heard many magpies squawking from about 300 yards away. It sounded like more than 30 birds, and their agitation calls meant one thing -- predator.

I returned back along the canal bank toward the noise. Along the way I passed several small piles of dark black feathers lying on the ground. The telltale, delicate, red epaulet feathers of the Red-winged Blackbird contrasted against their black ones. Obviously, some predator used this area for plucking and eating their prey. Was it the noted bird predator the Cooper's Hawk or perhaps a Northern Harrier, formerly known as the Marsh Hawk?

The magpie calls returned me to the task at hand. I slowly walked toward a large grove of cottonwoods and stopped often to scan the trees with binoculars, not sure for whom I searched. Perhaps a Long-eared Owl or Golden Eagle or even a Gray Fox -- all possible predators in the sloughs! The loud ruckus of magpies continued; I knew the predator was still present.

Near the bullfrog ponds an immature Red-tailed Hawk flew from a concealed perch. The heavily spotted undersides and barred tail were visible as the bird flapped. But the magpies let it go, no chase, no harassment. It was not the Red-tail they were after.

Just then I saw the large hawk with a white rump patch -- Northern Harrier -- fly from a cottonwood. And in its talons it held a lifeless magpie.

Northern Harriers hunt on the wing during the day cruising low over open fields or marshlands with their wings held in a V-like pattern. The birds systematically search an area by flying 5 to 30 feet above the vegetation. When prey is located, the Harrier either stalls in flight and pounces, or hovers like a helicopter for a better look, or a better listen.

Harriers have an owl-like face. The concave facial disk and relatively large off-set ears enable the bird to use triangulation of sound to help locate prey such as mice, voles, juvenile rabbits, frogs, pheasant chick, and other birds in dense vegetation. The female Harrier is larger than the male; hence, the female takes larger prey than the male. Now, I would add Black-billed Magpie to their prey menu, although magpies may represent a minute fraction of the Harrier's diet.

In one study, 25 % of the Harrier nests were associated with polygynous matings -- males bred with more than one female. Females construct most of the nest in tall weeds or reeds often on top of a low bush or knoll on dry ground. In the Moab sloughs, Harriers are winter residents but may be observed in summer. They are not known to nest in the sloughs.

As the Harrier flew away (it was either a juvenile or adult female), the magpies continued to harass the hawk. I wished the hawk good hunting, but from the prey remains I saw that day, perhaps these hawks of the marsh are already doing quite well.

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