Red-shouldered hawks are medium-sized hawks that are found throughout eastern and coastal North America. They are year-round residents in most of their range, staying in the same territories throughout the year. Red-shouldered hawks build nests in trees and lay eggs in spring. The young hawks hatch after about a month of incubation and remain in the nest, dependent on their parents, for several weeks as they grow. Eventually the young fledge and leave the nest, but may still be fed and cared for by the parents for a few more weeks before becoming fully independent. So in total, red-shouldered hawks may use the same nesting site for around 3-4 months from when eggs are laid to when the juveniles disperse.
Nest Building
Red-shouldered hawks form breeding pairs in late winter and early spring. They build a new nest or refurbish an old nest in March or April. The nests are made of sticks and twigs and lined with softer material like bark, leaves, moss or lichens. They are usually built 20-60 feet above ground in a crotch or fork of a tree branch. Both the male and female contribute to nest construction, though the female does more of the work. Building the nest can take 1-2 weeks.
Some pairs reuse old nests, either their own from previous years or an abandoned nest built by other hawks or crows. Refurbishing an old nest may only take a few days. Red-shouldered hawks have high nest fidelity and often use the same territory and even the same nest across breeding seasons.
Egg Laying and Incubation
Once the nest is complete, the female lays a clutch of 2-4 eggs. The eggs are laid at 2 day intervals. She begins incubating the eggs as soon as the first one is laid. The male brings food to the female while she incubates.
Incubation lasts for 28-33 days. The female does most of the incubating, but the male may incubate for brief periods to give the female a break. The eggs all hatch within a day or two of each other, despite being laid 2 days apart.
Nestlings
After hatching, the helpless nestlings are brooded by the female almost continuously for the first 10-14 days. The male provides food, which the female tears into small pieces to feed the nestlings. As they grow, the nestlings are able to eat larger prey items.
By about 3-4 weeks old, the nestlings are very active and may start flapping their wings in preparation for fledging. They stand up in the nest and walk along branches. The female continues to brood and shade the nestlings during the hottest part of the day.
Both parents share duties of providing food as the nestlings grow. Nestlings may remain in the nest for 4-6 weeks after hatching.
Fledging
The nestling period ends when the young hawks fledge, or make their first flight from the nest. Fledging occurs between 38-42 days after hatching.
The first flights from the nest are usually clumsy. The fledglings make short hops and flights between branches close to the nest. Their flying skills quickly improve over several days.
The parents continue to feed and protect the fledglings. Young hawks may return to the nest to roost after fledging. They become increasingly independent but still have poor hunting skills and rely on the parents for food for several more weeks.
Nest Dependence Period
For the first 1-2 weeks after fledging, the young hawks are still mostly dependent on their parents for food and protection. They improve their flying abilities but do not range very far from the nest.
Between 2 to 6 weeks after fledging, the young birds start to hunt small prey on their own close to the nest site. However, they still cannot fully provide for themselves and frequently return to the nest to be fed by the parents. This post-fledging dependence period may last about 6-10 weeks in total.
Dispersal from Parents
At approximately 8-10 weeks after fledging, the young red-shouldered hawks become independent of the parents. They disperse from their parents’ territory and have to hunt and survive fully on their own. Dispersal often coincides with the parents beginning a new nesting attempt for a second brood in late summer.
Some young hawks may remain briefly in their parents’ territory after this time. But most fully separate and begin wandering more widely by about 3 months of age.
Second Broods
Red-shouldered hawks may raise a second brood in a single breeding season. The female typically lays another clutch of eggs in late May through July, while still feeding fledglings from the first brood. The male takes over care of the first brood while the female incubates the new eggs.
Second broods follow the same nesting timeline, with eggs hatching after a month of incubation and young fledging after another 5-6 weeks in the nest. However the post-fledging period may be shorter for the second brood if they hatch late enough in summer, allowing the parents to start molting earlier. Second broods leave the nest independent by about 10 weeks of age.
Conclusion
In summary, the full breeding cycle for red-shouldered hawks, from initial nest building through the independence of offspring, runs from March through August:
– Nest building: 1-2 weeks in March/April
– Egg laying and incubation: 4-5 weeks in April/May
– Nestling stage: 4-6 weeks from May to June
– Fledgling dependence: 6-10 weeks from June to July/August
The actual time spent in the nest itself, from egg laying through fledging, is around 10-12 weeks. Most young red-shouldered hawks remain close to the nest and attended by parents for at least 2 months in total before dispersing from their parents’ territory and living fully independently. Pairs that raise two broods may reuse the same nest up to four months from March through July.
Factors Affecting Nesting Timeline
The exact nesting timeline for any individual pair can vary based on several factors:
– Geographic location – Northern populations nest later in spring than southern
– Weather – Colder spring weather may delay nesting. Hot dry summers may shorten post-fledging period.
– Prey availability – Lack of food may lower reproductive success and lengthen time in nest.
– Human disturbance – Disruption near nests may impact breeding and cause nest failure.
– Age and experience of parents – Younger pairs may have lower success or slower developing young.
– Brood size – More chicks may lengthen time in nest but reduce post-fledging period.
– Second broods – Timing compressed but may have shorter post-fledging period.
Monitoring banded hawks at nest sites helps provide more data on exact duration of each nesting stage across various conditions. But in most areas, the overall nest occupancy spans March through August.
Comparison to Other Hawk Species
The red-shouldered hawk has a relatively long nesting cycle compared to some other hawk species. Here is how it compares:
Species | Total Days in Nest | Days to Fledge |
Red-shouldered Hawk | 70-80 days | 38-42 days |
Red-tailed Hawk | 45-46 days | 38-43 days |
Broad-winged Hawk | 35-40 days | 28-34 days |
Cooper’s Hawk | 30-36 days | 28-34 days |
Sharp-shinned Hawk | 27-34 days | 24-27 days |
The longer nesting period for red-shouldered hawks is likely related to their smaller average clutch size of 2-4 eggs. Species that lay larger clutches, like broad-winged hawks, are able to fledge more young in less time. But each red-shouldered hawk nestling gets more attentive care over a longer nesting period.
Nesting Habits and Importance of Cavities
The long occupancy of red-shouldered hawk nests, often in the same trees used annually, makes their nest sites a limited and important resource. Loss of suitable nest trees and human disturbance of nest areas can reduce reproductive success.
Their preference for building nests in tree crotches makes them dependent on mature forests with large trees. They occasionally nest on cliffs, human-made platforms, or in tree cavities too. Tree cavities provide greater shelter and may enable red-shouldered hawks to inhabit areas with smaller trees.
Cavities used include natural hollows in live or dead trees and old woodpecker holes. In one study, red-shouldered hawks used cavities for 13% of nests monitored over 10 years. Pairs nesting in cavities were significantly more successful, averaging 0.9 more fledglings per nest than pairs in open crotch nests.
Providing artificial nest boxes may help attract red-shouldered hawks to smaller woodlots if natural cavities are lacking. The extended occupancy of their nests, lasting nearly half the year from egg-laying through independence of young, means each successful site is a valuable asset requiring protection.
Threats to Nesting Sites
The specific nesting requirements of red-shouldered hawks make them vulnerable to certain habitat changes:
– Logging of mature forest stands with large trees.
– Loss of wooded wetlands and riparian areas.
– Development and human encroachment near nest sites.
– Lack of forest management leading to few younger trees becoming suitable for nests.
– Competition for cavities from other birds and mammals.
With such a long nest occupancy, disruption during the breeding season can quickly lead to nest failure and loss of young. Even if pairs re-nest, late nests may fledge fewer or weaker young.
Changes to land use practices that preserve old nesting habitat and limit disturbance around known nest sites during spring and summer may help counter declines in red-shouldered hawk populations. Proper forest management ensuring recruitment of new large trees can maintain nest sites long-term. Artificial nest structures may also mitigate some habitat limitations and enable red-shouldered hawks to succeed in more developed areas.
Conservation Status
The red-shouldered hawk has a wide range but has declined in some regions, especially northeastern North America. Habitat loss and degradation are major contributors to declines in heavily populated areas. The species is still common in the southeastern United States. The red-shouldered hawk has an IUCN status of Least Concern globally but is listed as Threatened or Endangered in several states:
State | Conservation Status |
Vermont | Endangered |
New York | Threatened |
Ohio | Species of Concern |
Maryland | Threatened |
Ongoing monitoring is important to detect population trends and identify specific habitat needs. The long-term occupancy of nests means focusing conservation efforts around known breeding sites can efficiently support red-shouldered hawk reproduction. Their nesting requirements and fidelity to nest sites should be considered when managing forest habitat across the species’ range.
Summary of Red-Shouldered Hawk Nesting
To summarize key points:
– Red-shouldered hawks remain in nests for an extended period from March to August.
– Typical stages are 1-2 weeks nest building, 4-5 weeks incubation, 4-6 weeks as nestlings until fledging, then 6-10 weeks dependence post-fledging.
– Young fledge at 38-42 days but are fed by parents for several more weeks.
– Total time using the nest is around 3-4 months for each brood.
– Pairs may raise a second brood reusing the same nest.
– Access to cavities and mature forests with large trees support nesting success.
– Disturbance should be limited near nests during breeding season.
– Conservation efforts should protect known nest trees and habitat.
Conclusion
Red-shouldered hawks have a prolonged nesting cycle compared to many raptors. A successful breeding pair may occupy a nesting territory for up to half a year from initial nest building through the independence of their young. The long occupancy of nests, lasting from March through August, means providing protected breeding habitat is an important factor in the conservation of red-shouldered hawk populations. Although dependent on parents for an extended period, the red-shouldered hawk’s slow development ultimately equips the young with the skills needed to survive and breed themselves, thereby perpetuating the species’ nesting cycle into the future.