An adult Bald Eagle tries to drag a large fish, probably a carp, across the ice on Black Creek west of Savannah, NY. The photo was taken from the shoulder of Rt. 31 just west of Messner Road where Black Creek exits the Montezuma Marshes and flows north toward Crusoe Creek. (photo © Dave Spier)
A Northern Harrier hunts at Muckrace Flats beside Savannah Spring Lake Road northeast of Savannah, NY during the 2010 Muckrace. (Photo © Dave Spier)
The Northern Harrier, once known as the marsh hawk, is a slender and buoyant raptor with a somewhat owl-like face. The hawk's long wings and tail are designed for life in the open. A distinctive white rump patch can be seen when the bird's flight tips sideways toward you, or, sometimes, the white can be seen as the bird departs. When soaring, the wings are held in a shallow V with the tail fanned. At low altitudes, the tail is usually closed and the wings may be held flat to the sides. In a steep glide, the wings are sharply bent and swept back like a fighter jet.
The harrier's Latin name, Circus cyaneus, refers to its circling flight and the supposedly blue plumage of the males. The color is actually gray, but that's only half of the story because females and juveniles are brown or orangish, an unusual disparity for raptors. The name harrier is Old English for "harassing with hostile attacks." Other colloquial names include blue hawk, mouse hawk and white-rumped hawk. Males are smaller and more agile and catch smaller prey, including smaller birds. The larger females are more intent on larger meals.
Harriers nest in the marshes at Montezuma National Wildlife Refuge. One April I watched a female repeatedly carry nesting material in her beak and then drop down into the same patch of heavy vegetation. There are indications harriers also may nest in the Northern Montezuma Wetlands Complex around Savannah. They almost certainly nest in the Lakeshore Marshes Wildlife Management Area in northeastern Wayne County as well as Howland's Island. The female does all the incubating while the male brings food. After the eggs hatch, the male continues supplying prey, but only the female tears it up and feeds the young. If something happens to her, the nestlings will starve, even though the male continues to drop whole prey into the nest.
Harriers breed from Alaska across Canada to the Maritimes and south into the United States as far as a line from California to Pennsylvania. In warm weather they hunt snakes, frogs and insects in addition to small mammals. When all else fails, carrion is eaten.
Last fall, a young harrier spent some time at the Montezuma Audubon Center. Sometimes it flew close to the building, passing the west windows and then disappearing across the field. I doubt it was hunting the birds at the feeder, but they are within the realm of this raptor's diet. Mostly it flew low over the grasslands and the marsh while looking for small mammals, especially Meadow Voles (also called field mice) which are caught with a sudden pounce. Sometimes the large bird's flight drifted back and forth, then stopped momentarily to hover. After hanging around for several weeks, the first heavy snowfall of the season didn't seem to phase it, but it did finally move on. Most harriers head south for the winter and return in the spring. Those that do stay for the winter hang around with Short-eared Owls and share the same fallow, grassy fields where mice have had time for a population explosion. Both species will use fence posts for hunting perches as they listen for prey. Though they are unrelated species, the facial disks of both harriers and owls seem to help focus sounds on the ears.
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They're easiest to see when they sit on power lines and watch the grass below. In the absence of these utility perches, they may simply turn into the wind and hover on beating wings. Oil droplets coating the bird's eyes filter out haze and glare. Retinas, each packed with a million light-collecting cells, give it vision eight times better than a human's. Theoretically they could see a mouse from the top of the Empire State Building. Once prey is spotted, the hawk drops like a stone and reaches out with needle-sharp talons.
I've also heard of them gliding downhill and grabbing a mouse that was running across the snow -- a most foolish thing for rodents to do. This maneuver caught the attention of two crows which gave chase, causing the kestrel to drop its prey. Undaunted, the hawk circled back and retrieved its fallen victim according to the account.
The American Kestrel, Falco sparverius, was once known as the sparrow hawk, a name derived from its winter habit of eating small songbirds, but in reality these comprise only one-third of the hawk's winter diet. On an annual basis, mice and other small rodents, plus a few frogs and reptiles represent a much larger portion of its intake. During warm weather it eats primarily insects, and late in summer the kestrel dines almost exclusively on juicy grasshoppers which are plentiful and easy to catch. This earned the bird the nickname "grasshopper hawk" from early ornithologists. Kestrels also eat crickets, cicadas, moths, beetles and ants. Small snakes are readily dispatched, but large snakes present a problem if they wrap themselves around the bird's legs. Small roadkills, and songbirds that fly into windows, are a source of easy meals.
Kestrels are the smallest members of the falcon family. Males are nine inches long while the larger females may reach 12 inches. On average they're about the size of a robin or blue jay which makes all these birds vulnerable to larger winged predators, especially Cooper's Hawks. On the other hand, kestrels will not tolerate competitors in their hunting territory and have been known to chase off larger, but less agile, raptors like the redtail. The falcon family also includes the kestrel's larger and more famous cousin, the Peregrine, which is uncommon.
If you're close enough, kestrels are easy to recognize. In addition to small size, look for bold black marks on a white face creating a "mustache" and "sideburns." Males have gray wings and rusty-red tails ending with a black band and white feather tips. Females are mostly rufous-brown with fine cross-barring on the back, wings and tail. The lighter undersides of both are spotted, giving way to white under the tail. The wings and tail are relatively long, much like the larger harriers which also hunt the open countryside. (Harriers, also displaying sexual plumage differences, are in a different family.) Unlike harriers, falcons are noted for flying with pointed wingtips, an advantage for faster speed. Peregrine Falcons, which can reach a diving speed over 200 mph, are the fastest animals on earth.
Kestrels are year-round residents throughout New York and most of the United States, and a summer breeder across much of Canada and the northern Great Plains states. They nest in tree cavities, often taking over old woodpecker holes, but cutting dead trees for firewood results in a shortage of natural nesting cavities. Fortunately, kestrels readily take to large nest boxes erected specifically for the purpose. The size should be at least eight inches square inside and 15 inches tall with a three-inch entrance hole centered three inches below the top. Mount it at least 10 feet above the ground. As controllers of insect and mouse populations, kestrels are valuable to gardeners and farmers, and nest boxes are one way to encourage their presence. For information on the American Kestrel Nest Box Project on the Montezuma Wetlands Complex, see the dedicated News page on this website.
During the 2009 Montezuma Christmas Bird Count, 13 Short-eared Owls (Asio flammeus) were reported. Many of the birding groups stopped by Van Dyne Spoor Road in the Town of Savannah on their way back to the Montezuma Audubon Center for the evening’s final compilation. In addition to finding a retiring Northern Harrier and a Northern Shrike being chased by a Cooper’s Hawk, nine short-ears were still flitting over the fields and crossing the road.
Because of their long wing spans (38 to 42 inches) relative to body size (14 to 15 inches long), Short-eared Owls fly like giant moths, a common comparison for the owl’s typical pattern. Aside from this moth-like flight which begins in late afternoon, Short-eared Owls can be identified by light-colored facial disks surrounding bright-yellow eyes that face forward in typical owl-like fashion for binocular vision and depth perception. From the side, the owl’s head appears large and block-shaped and seems to be attached directly to the body without a neck. I nickname them “block-heads.” The so-called “ears” are just tufts of feathers used to signal other owls or help them blend into dry grass while resting. Sometimes these feathers are flattened and invisible. The real ears are hidden under feathers on the sides of the head. Typical of owls, one ear is higher than the other to help in accurate location of prey sounds.
The owl is colored buff and brown on the back and wing tops but is very light with faint streaking underneath, again to aid in camouflaging. The upper breast is more heavily streaked. The underwings are white with black “wrist” marks and dark wing tips. Overall this owl is slightly smaller than a crow.
The Short-eared Owl is now primarily a winter visitor in Western and Central New York. Decades ago, the species bred in various grasslands around New York State, but like the disappearance of so many other grassland birds, the short-ear had only four confirmed nest sites (three of them in northern New York) during the 2000-2005 Breeding Bird Atlas. The short-ear is a declining species and is listed as Endangered in New York. The National Audubon Society lists it as a species of national conservation concern.
Short-ears are attracted to large, open tracts of open grassland with high vole densities. This is the same habitat preferred by harriers and the two species are often found together. Both fly low to the ground while hunting. The owl may briefly hover before pouncing or dropping on its prey. I’ve also seen them dive directly from fence posts where they’ve been watching the field.
The Department of Environmental Conservation (D.E.C.) along with a number of volunteers is conducting a study of Short-eared Owls at several sites in central and western New York including the Montezuma Wetlands Complex. The goal is to document all of the owl’s wintering locations and establish long-term population monitoring efforts at both foraging and roosting sites. Several sites around Montezuma have already been identified and several owls have been live-trapped and outfitted with tiny radio transmitters that allow their movements to be tracked. If you see a vehicle parked beside a country road in the late afternoon or after dark and
someone is pointing a hand-held antenna, it might be one of the owl researchers.
Another aspect of owl research is monitoring their prey. D.E.C. Wildlife Biologist Jim Eckler has established three sets of live traps in three different habitats at the Montezuma Audubon Center. On the afternoon of January 11, students from Clyde-Savannah Middle School helped check the traps and record the findings. Traps with “occupants” were brought inside and the small mammals were released into large terrariums so they could be identified. Most were Meadow Voles (field mice), but Short-tailed Shrews, a White-footed Mouse and a Red Squirrel were also caught and then released. Students from other after-school programs are also helping. Results will be used to manage grasslands that benefit Short-eared Owls.
Short-eared Owls sometimes hunt from fenceposts. (photo © Dave Spier)
By the way, yes, there’s also a Long-eared Owl. This species hides in conifer plantations rather than hunting open country.
More photos of Short-eared Owls can be found on the Montezuma Birding Trail Yahoo website, http://groups.yahoo.com/group/montezumabirding/ [click on “Photos” in the left menu and then open the album “birds in winter (raptors)”] Comments, questions and suggestions may be sent to The Northeast Naturalist.