Rough-legged Hawk Nest
Buteo lagopus

f13 @ 1/500s, ISO:1000, Nikon D300S w 17-55mm @ 38mm

"Rough-legged Buzzard," Wikipedia, the free encyclopedia. The rough-legged buzzard, also called the rough-legged hawk, is a medium-large bird of prey. It is found in Arctic and Subarctic regions of North America and Eurasia during the breeding season and migrates south for the winter.Sexual maturity is reached at about two years old. Breeding generally occurs during May but is variable depending upon dates of arrival at breeding grounds. The rough-legged hawk is thought to be monogamous, mating with a single individual for multiple years. No evidence currently suggest otherwise. Nests are built soon after arrival to breeding grounds and require 34 weeks to complete. Twigs, sedges and old feathers are used as building materials. Nests are 6090 cm (2435 in) in diameter and 2560 cm (9.823.6 in) in height. Cliff ledges and rocky outcroppings are preferred nesting sites. Females can lay 17 eggs but will typically lay 35. Average egg size is 56.4 mm (2.22 in) in length by 44.7 mm (1.76 in) in width. Minimum incubation period is 31 days, provided almost exclusively by the female. The male feeds the female during this incubation period. After hatching, young require 46 weeks before fledging the nest. Fledglings depend on parents to provide food for 24 weeks after leaving the nest.
Cambridge Bay, Nunavut, Canada