While many birds nest in warmer months, some hawk species begin their nesting activities during winter. This period presents unique adaptations as they prepare for the breeding season.
Do All Hawks Nest in Winter?
Hawk nesting behavior varies significantly by species and geographic range. Many migratory hawks breed in warmer winter climates. In contrast, resident species may remain in colder regions and begin their nesting cycle in late winter.
Red-tailed Hawks, common across North America, are a prominent example. They often start nest construction or repair in late February and March. While eggs are typically laid in March or April, initial courtship and nest preparation occur during winter. Great Horned Owls also nest early, with some pairs incubating as early as December or January, even in snow.
Preferred Winter Nesting Locations
Hawks nesting in winter select locations offering stability and strategic advantage. They commonly build nests in tall, mature trees, often those standing higher than surrounding vegetation. These can be deciduous trees, where nests become visible before leaf-out, or conifers providing year-round cover. Nests are typically high in the tree’s crown or a major branch fork, ranging from 13 to 120 feet above ground.
Beyond natural tree sites, hawks also use cliff ledges. Their adaptability extends to human-made structures, especially where natural sites are limited or in urban areas. Hawks have been observed nesting on utility poles, communication towers, and billboards.
Factors Influencing Nest Site Selection
Several factors influence winter nest site choice, contributing to hawks’ survival and breeding success. A primary consideration is a commanding view of the landscape. This elevated position allows hawks to effectively hunt and monitor their territory for threats.
Nest sites also require robust support for the nest’s weight, adult birds, and young. Strong tree forks or stable ledges are essential. Selected locations offer protection from harsh winter weather, including winds and snow, and security from ground predators. Proximity to reliable food sources is also important, as prey can be scarcer in winter.
Characteristics of Winter Nests
Hawk nests built or used in winter are typically large and robust structures. A Red-tailed Hawk nest, for instance, commonly measures 28 to 38 inches (71 to 97 cm) in diameter and up to 3 feet (90 cm) in height. Some large hawk species, like the Ferruginous Hawk, construct nests exceeding 3 feet in both height and width.
These nests are primarily constructed from sticks and twigs. The inner cup is lined with softer materials for insulation and comfort. Common lining materials include bark strips, pine needles, corn cobs, husks, and aspen catkins. Hawks often reuse nests from previous years, adding new materials each season, which contributes to their size and visibility against bare winter trees.