By William LeRoy
It is truly a privilege to live in Arizona. Arizona’s contrasting habitats make Arizona one of the most exciting regions to observe raptors in North America, with more raptor species living in and visiting our state than any other state in the U.S. Because northern harriers winter in Southern Arizona, snowbirds and those of us who are full time residents have the opportunity to see one the most unique raptors in North America.
Did you know that the northern harrier is the only non-owl raptor (hawk) that has a distinctive owl-like face? This facial shape aids their sense of hearing and allows them to locate rodent prey by sound. Like owls, the Harrier will move their facial disk feathers in flight to adjust the sounds and home in on their prey. Harriers are found throughout the world, but the only representative of this group in North America is the northern harrier.
Description
Northern harriers, also known as marsh hawks, are long-winged, long-tailed birds of open terrain. They can be seen coursing low over fields, pastures and marshes in search of prey. Their buoyant, veering flight is very distinctive. They can also be seen hovering vertically over their prey before attacking, just like the Harrier Jump Jets that bear their name. Harriers are slender birds, 18 to 23 inches in length, with wingspans of about 4 feet. Although large, they are light in weight, weighing approximately one pound. Adult male Harriers are silvery-blue with black wingtips; adult females are dark brown above and have brown streaks on their white underparts. The young (both male and female) resemble the adult females. All Harriers have a white rump patch.
Hunting and Prey
Typically hunting from a slow, buoyant flight, usually quite low to the ground, the northern harrier takes a variety of prey, ranging from small mammals and birds to reptiles, amphibians, insects, larger mammals and birds, and sometimes carrion. Northern harriers perform spectacular roller-coaster flights and prey transfers high in the air while courting.
Family Life
The northern harrier commonly perches and even roosts on the ground, and outside of the breeding season often gathers in communal roosts, sometimes numbering tens or even, rarely, hundreds of birds. It also often nests in loose colonies, sometimes practicing an unusual degree of polygyny, with males simultaneously raising several broods with as many as seven different females. Breeding usually takes place from April to July (2), the male performing a spectacular aerial ‘sky-dance’ at the start of the season, involving a series of steep climbs and near vertical plunges, with twists, rolls, spirals and loops, accompanied by much calling. The nest is built on the ground, usually in dense clumps of vegetation, and comprises a pile of sticks, grasses, sedges and other materials. Around 3 to 6 eggs are laid, and are incubated by the female for 29 to 31 days. During this time, and until the chicks are about two weeks old, the male brings almost all the food, transferring it to the female in impressive aerial passes, in which the food is dropped by the male and then caught by the female in mid-air. The young fledge at 29 to 42 days, and are dependent on the adults for several more weeks. Sexual maturity is reached at around 2 to 3 years, and lifespan may be up to 16 years.
Habitat and Viewing
The Northern harrier breeds in North America from Alaska east to subarctic Newfoundland and Labrador and south to the northern states. Resident population across U.S. from Pacific Coast to the Great Lakes. Spends winters southwest and Pacific coast through Mexico and the West Indies to Central America. Preferred habitats include open fields, savannas, meadows, and marshes. Look for them in the more open spaces of the Sonoran Desert and near the Verde and Salt Rivers.
Migration Status
As with most species that prey heavily on voles, northern harriers are somewhat nomadic, and densities change with the abundance of prey. Throughout much of their range, they are long-distance migrants, wintering as far south as Panama, but they are resident in other areas, including Northern Arizona.
Conservation Status
During the middle of the 20th Century, northern harriers experienced declines due to pesticide use. The regulation of DDT has helped the harrier population recover, although habitat loss is still a significant threat. Many wetlands and open spaces are in danger of development or conversion to less beneficial habitat. Overgrazing also affects their habitat. Numbers have severely declined in the East due to increasing numbers of ground predators and lack of habitat. Northern harriers are, however, fairly adaptable and generalized, and seem to be fairly stable in North America in spite of these threats. Numbers are, however, on the decline globally.
About Wild At Heart
Wild At Heart is an all-volunteer organization which is dedicated to the conservation and preservation of Arizona’s native wildlife. At Wild At Heart we: Rescue, rehabilitate, and release birds of prey which have been injured or orphaned. Relocate displaced burrowing owls. Manage species recovery programs. Manage habitat enhancement projects. Provide educational presentations. Each year, Wild At Heart rescues and cares for approximately 400 owls, hawks, and falcons, and some years, as many as 600 raptors have been cared for in the facility. Every single dollar donated goes towards the rescue, rehabilitation, care and release of our amazing Arizona Birds of Prey.
Wild At Heart is an all-volunteer non-profit 501(c) 3 organization. Support for Wild At Heart comes from generous members of the community who are concerned about our ever-decreasing wildlife habitats.
Please send your tax-deductible donations to “Wild At Heart” at the following address: Wild At Heart, 31840 N. 45th Street, Cave Creek, Arizona. 85331. For additional information regarding how you can support Wild At Heart please go to: http://www.wildatheartowls.org/
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