Short-eared owl

The breeding range for Short-eared owls extends from Alaska into Canada, and the northern United States south to northern Virginia, Kansas, and central California.

Historically, they nested in New Jersey in marshes along the Atlantic and Delaware Bay coasts. By 1979-80, only three breeding areas were known to still be occupied, Barnegat, Turkey Point, and the Tuckahoe River.

In New Jersey, short-eared owls inhabit coastal tidal and brackish marshes, inland fields, pastures, and grasslands. Vast areas of low marsh or thick stands of phragmites do not offer high quality habitat for these owls. Prime habitat for the Short-eared owl consists of large areas of coastal high marsh adjacent to undisturbed upland fields.

Short-eared owls roost, forage, and nest at inland open areas, such as fallow fields, hay fields, grasslands, airports, and sedge meadows. They are very sensitive to human activity. They require large tracts of undisturbed open areas.

Short-eared owls occupy similar habitats throughout the year. They form winter roosts on the ground within open areas. Wintering roosts of short-eared owls have been documented in several species of conifers, particularly during periods of heavy snow cover. Sometimes wintering short-eared owls concentrate at landfills where rodents are abundant.

The Short-eared owl primarily consumes a variety of small mammals. Meadow voles (Microtus pennsylvanicus) amounts for a large portion of its diet. They consume one to two voles per day and are very valuable at keeping rodent populations in check. Many owls directly rely on an abundant food resource. From year to year, the amount of prey may vary. If prey is not abundant, then reproductive success in owls is usually depressed.

Short-eared owls are nocturnal, or are active at night. They may also be active during dawn and dusk. During the breeding season some owls may hunt during the day to supplement their normal foraging time to provide enough food for their young.

In late winter and early spring owls begin to seek mates and then establish pair bonds. Males perform aerial displays during day or night. He flies up in the air in tight circles then performs steep dives. While performing the displays the male produces a clapping noise with his wings. He calls using.jpg’epeating hoo calls.

They build nests on the ground in open areas, such as fields or marshes. Females construct the nest in the vegetation by scraping a bowl type shape and lining it will grasses and feathers.

During May, the female lays between four to seven buff-colored eggs. Eggs are laid at two day intervals. She starts to incubate when the first egg is laid. This is referred to as asynchronous hatching. After 24 to 28 days the eggs hatch. The young are different ages. This strategy allows for the older and stronger young to survive if food is scarce. The male does most of the foraging and provides food for both the female and its young. In two weeks the young are old enough to roam around the nest in the surrounding vegetation, but they can not fly. During this time the young get familiar with their surroundings and watch the adults hunt. In four weeks the young are old enough to fly or fledge. The young can fly but still rely on the adults for food until they are about 7 to 8 weeks old.

One roost, in Princeton (1878-79) contained nearly 200 owls.

Short-eared owls historically bred along the Atlantic and Delaware Bay coasts of New Jersey. During the early 1920s, numerous nests were documented in salt hay marshes in Elizabeth. Large concentrations of short-eared owls occurred in New Jersey during the winter months. One roost, in Princeton (1878-79) contained nearly 200 owls. Shooting and egg collecting initially may have caused reductions in historic populations. Later, habitat loss played a greater role in the species decline. The filling of coastal marshes after World War II greatly reduced habitat for these owls. By the 1950s, the short-eared owl had declined as a breeding species in much of the Northeast, including New Jersey.

Due to habitat loss and severe population declines in the state, the short-eared owl was listed as a threatened species in New Jersey in 1979. The last confirmed nest site was in 1979. Only a handful of sightings were reported during the breeding season in the early 1980s. This prompted biologists to upgrade their status from threatened to endangered in 1984.

The U.S. Fish and Wildlife Service designated the short-eared owl a Migratory Nongame Bird of Management Concern in the Northeast in 1992. Other surveys, including the Christmas Bird Count and the Breeding Bird Survey, revealed significant declines in owls. The short-eared owl remains an extremely rare and possibly extirpated breeding species in the state. These owls have declined throughout the northeastern United States. They are listed as endangered in Massachusetts and Pennsylvania, threatened in Connecticut, and of special concern in New York and Maryland.

The primary threats to Short-eared owls in New Jersey are habitat loss, human disturbance, and prey availability.