Northern goshawk

Goshawks range from Alaska and Canada south to California in the west and southern New England and the Appalachian Mountains in the east. Over the past few decades the goshawks range has moved south into New Jersey, New York, Pennsylvania, and Connecticut. Some remain in their breeding range year-round and others migrate south. Wintering goshawks are irruptive or their numbers can rapidly increase in certain areas depending on prey availability. When prey is scarce in the northern areas of their wintering grounds they occur in greater numbers at the southern portions of their wintering grounds.

The northern goshawk nests in mature, unfragmented forests. It is important that those forests are safeguarded from human activity and development. Breeding habitat for goshawks are forests that include large-sized trees, a closed canopy, and an open understory. They may nest in wooded swamps, lower gentle slopes, or flat areas. Northern goshawks may occupy coniferous, deciduous, or mixed forests. Nests may be located in either deciduous or coniferous trees, although deciduous trees are used more frequently by goshawks nesting in New Jersey. Nests are constructed in a crotch of a large tree. In their territory goshawks maintain “plucking posts.” Favored sites where they consume their prey are trees, stumps, fallen logs, or old nests. Goshawks use a wider variety of habitat during the non-breeding season. Forested areas are preferred for roosting. They provide cover and shelter against harsh winter weather.

Northern goshawks are strong predators that mainly consume birds. They are well adapted at chasing and capturing prey within dense forests. Their short rounded wings and long tail enable goshawks to maneuver between trees and through thickets of vegetation with ease. They are opportunistic and rely on different prey items during the different seasons. The male goshawk (which is smaller than the female) catches mainly songbirds. The larger female can catch larger birds like grouse, pheasants, rabbits, squirrels, pigeons, and crows. They may occasionally take some other mammals, retiles, and insects.

Northern goshawks that breed in New Jersey remain near their nest sites year round. Pairs return to their nesting territories in February or March. Both male and female goshawks perform aerial courtship displays. They soar in circles high above their territories while calling and fanning out their feathers. They sometimes fly in an undulating flight. They flap their wings slowly and descend quickly then rebound upward repeatedly. Goshawks typically do not breed until they are three years old. Some females do breed when they are only two years old.

Goshawks build stick nests. It is primarily built by the female. Sometimes their nesting territories may contain several nests that are constructed over the years. Nests are located in large deciduous trees on large branches or in main forks of trees. It is constructed of sticks and twigs and lined with bark strips, conifer needles, and down feathers.

In mid to late April females lays 3 to 4 eggs. The eggs are laid at two day intervals. The female begins incubation after the first egg is laid. The female incubates for 36 to 41 days. The young hatch asynchronously or in the order that they were laid. This adaptation gives the older young a better chance at survival if food is scarce. The female broods the young and feeds them for the first 8 to 14 days. At 34 to 40 days old the young “branch out” to nearby branches to strengthen their flight muscles before fledging in a few more days. After fledging the young begin to hunt but they still rely on their parents for food.

Historically, northern goshawks were shot in large numbers by farmers and hunters who regarded the goshawk as a pest because it consumed chickens and game birds. In 1929, Pennsylvania passed a law entitling gunners a $5 bounty for each dead goshawk. Today many conservation efforts have protected birds such as the goshawk, rather than harm them.

The northern goshawk was not discovered as a breeding species in New Jersey until the later half of the 20th century. Breeding was suspected in the 1950s. The first goshawk nest in New Jersey was confirmed in 1964. During the 1960s and 1970s, the goshawk expanded its breeding range in the northeast, nesting in northwestern New Jersey, Pennsylvania, New York, and Connecticut. The maturation of eastern forests may have facilitated the surge in nesting goshawks.

Since goshawks need large contiguous old-growth forest it was listed as a threatened species in New Jersey in 1987. Due to the increasing threats facing forested habitats and the scarcity of nesting goshawks, the status of the goshawk was reclassified as endangered in 1999. In 1995, the first goshawk nest was discovered in the Pinelands of southern New Jersey. Perhaps in the future contiguous, mature forests protected in the Pinelands will provide additional sanctuary for nesting goshawks, enabling them to expand their range and increase their population in the state.

Current threats to the northern goshawk include habitat loss and human disturbance in New Jersey.