distance of more than a half mile.
The male might fly as high as 1,000 feet or as low as 30 feet. Typically, a display will include about 25 maneuvers about 70 feet above the ground. The males often display over a suitable nesting area.
Once a male and female have tentatively bonded, they will soar together and transfer food in mid-air. The males begin feeding the females when the latter are heavy with eggs.
Another aspect setting northern harriers apart from other hawks is that at least some of the males are polygynous. Those males that end up with multiple mates are the ones who tend to sky-dance the most vigorously. The prevalence of polygyny seems to be tied to the abundance of prey during spring. So, in springs with lots of food, there might be more males with up to five mates than there would be during food-poor years.
Of course, northern harriers don't lead carefree lives of hunting and raising young. There are a number of other animals that would be more than happy to dine on harrier eggs, nestlings, inexperienced fledglings and incubating females. These predators include mammals, such as foxes, dogs, coyotes, skunks and raccoons. Livestock and white-tailed deer can inadvertently step on eggs and nestlings.
Why didn't I see a northern harrier while living in Farmington my first year? There are probably a number of reasons. For one thing, northern harriers are uncommon in Missouri and are listed as endangered because they don't breed much in the state.
Northern harriers breed here and there in western Missouri and at scattered locations across the northern part of the state. People see them more often in the spring and fall as the birds move to and from their winter quarters. So if I missed the spring and fall migrations that first year, my chances of seeing a harrier were low.
The former name for northern harriers was "marsh hawk," which is a pretty good description of where this species generally is found in the midwestern and northeastern United States. Farther west, northern harriers use prairies, cropland and sagebrush plains. East or west, the densest populations of northern harriers generally are associated with large tracts of undisturbed habitat. That sort of undisturbed territory can be hard to find in Missouri and might best be represented by some of the hay prairies in the southwestern part of the state.
Populations of northern harriers are declining in some parts of the country and increasing or remaining stable in other parts. As with many other species of birds, declines may be due to pesticides or other contaminants in the environment, coupled with the loss or degradation of breeding and wintering habitat due to human development. Fortunately, management that is designed to help other species, such as wetland preservation for waterfowl, can be helpful for northern harriers.