Quick Answer
Sharp-shinned hawks are territorial during the breeding season, defending their nesting areas from other sharp-shinned hawks and potential predators. However, their territories are relatively small, only extending up to a quarter mile around the nest. Outside of the breeding season, sharp-shinned hawks are not territorial.
Sharp-Shinned Hawk Overview
The sharp-shinned hawk (Accipiter striatus) is a small bird of prey found throughout North America. Some key facts about sharp-shinned hawks:
- Length: 9 to 13 inches
- Wingspan: 16 to 22 inches
- Weight: 3.5 to 8 ounces
- Lifespan: Up to 12 years in wild, up to 16 years in captivity
- Habitat: Deciduous and mixed forests across North America
- Diet: Small birds, sometimes small mammals and insects
Sharp-shinned hawks have blue-gray upperparts and white underparts with reddish barring. They have a squared-off tail with black and white bands.
Males and females have similar plumage, but females are up to one-third larger than males. Juveniles have brown upperparts and streaked underparts.
Breeding and Nesting
Sharp-shinned hawks are seasonally monogamous. They form breeding pairs during the mating season, but the pair bond only lasts for one season.
Courtship displays include diving displays, aerial acrobatics, and “sky-dancing” displays. Once a pair forms a bond, they cooperate to build a stick nest lined with bark, feathers, and fresh greenery.
The nest is typically placed high up in a conifer tree, 10 to 50 feet above ground. Sharp-shinned hawks are secretive around their nest sites and will dive bomb or attack anything they perceive as a threat.
The female lays between 3 to 8 eggs which hatch after about a month. The chicks fledge the nest at around 4 weeks old but remain dependent on the parents for another 3 to 4 weeks as they learn to hunt.
Territory Size and Defense
During the breeding season, sharp-shinned hawks become territorial, defending the area around their nest site against intruders. Their territories are relatively small, often only extending around a quarter mile radius from the nest.
Both the male and female will defend the territory by making alarm calls, performing aerial displays, and aggressively dive bombing potential predators or competitors. They are fiercely protective of their nest and will attempt to drive off much larger birds, even pursuing human intruders.
Territorial behavior peaks during courtship and early nesting season. The hawks must protect critical resources like nest sites and food supply within their territory.
As the breeding season comes to an end, the hawks become less territorial and are more tolerant of intruders. After the young fledge and disperse from the parents, the pair bond breaks and the adults abandon their breeding territory.
Territory Size
Studies on sharp-shinned hawk territories have found the following territory radii around their nest sites:
- Wisconsin: 0.13 to 0.93 miles (average 0.5 miles)
- Michigan: 75 to 440 yards (average 250 yards)
- British Columbia: 30 to 310 yards (average 146 yards)
Their small territories are likely due to the limited availability of suitable nesting habitat and the abundance of songbird prey near nest sites. Larger hawks may control better hunting areas, relegating sharp-shins to marginal territories with sufficient but smaller food supplies.
Foraging and Hunting Ranges
While sharp-shinned hawks are territorial around their nest sites during breeding season, they have much larger home ranges and foraging areas outside of the breeding season.
Resident sharp-shinned hawks maintain expansive non-breeding season home ranges. Some studies have found non-breeding home range radii of up to 9 miles from a central point.
Migratory populations also defend temporary foraging territories during migration and on wintering grounds. These temporary territories provide access to prey and cover in unfamiliar areas along their migration routes.
Sharp-shinned hawks frequent locations with ample bird feeders, nesting songbirds, and brush piles which attract their preferred prey. They often perch inconspicuously on a central vantage point and ambush birds that come near.
Interspecies Interactions
Sharp-shinned hawks may compete with larger accipiter hawks like the Cooper’s hawk for hunting and nesting territories. Although fiercly territorial with their own kind, breeding sharp-shinned hawks are often harassed and driven from their territories by these larger relatives.
Sharp-shinned hawks themselves are known for displacing smaller woodland birds like jays and flickers from preferred habitat during the breeding season. Their aggressive defense of tiny territories ironically makes them bullies of birds only a fraction of their size.
Beyond hawks, common nest predators of sharp-shinned hawk eggs and nestlings include:
- Crows
- Jays
- Raccoons
- Snakes
- Squirrels
Adult sharp-shinned hawks may be killed or injured by larger raptors like great horned owls, red-tailed hawks, and eagles.
Habitat Loss and Fragmentation
The widespread fragmentation and destruction of native forests across North America has impacted sharp-shinned hawk populations.
While they inhabit both mature and disturbed forest types, loss of continuity between woodland habitat patches appears to limit their distribution and breeding densities.
Fragmented habitats may also increase competition with other accipiters for reduced resources like nest sites and prey.
Protecting migration corridors and improving habitat connectivity between isolated forest stands would likely benefit sharp-shinned hawk populations.
Conclusions
In summary:
- Sharp-shinned hawks defend small breeding territories around their nest sites
- Territories only extend around 0.25 miles from nest on average
- Territorial behavior peaks during courtship and early nesting seasons
- Outside breeding season, sharp-shins use much larger foraging ranges
- Habitat loss and fragmentation may be reducing available breeding territories
Though fierce defenders of tiny breeding territories, their small size relative to other hawk species likely restricts them to marginal habitat patches with adequate but not ideal food resources. Protecting habitat connectivity could benefit sharp-shinned populations by providing improved access to nesting sites and prey across the landscape.
