Male and female of Osprey are similar. Adult Ospreys have dark-brownish upperparts, buffy-white head with broad brownish patch passes from forehead to nape; same dark-brownish strips passes across eyes and ears; all underparts are buffy-white with dark spats on craw; underwings are pale with marble pattern; flight feathers are brownish above; tail is cross-barred. Juveniles in first plumage are dark-brownish above with whitish edges of feathers, especially on shoulders and wing coverts; crown is whitish in brownish shift-streaks (extended feathers of nape formed crest); flight feathers are dark-brownish with pale bases; tail feathers are dark cross-barred.This plumages in second year changed by final plumage of adult bird. Eyes are yellow, bill is bluish on base, black-horn in median and on tip; legs are leaden sometimes greenish tinged; claws are black. SIzes: males wing 448-492, females wing 485-515, males tail 207, females tail 227, tarsus 50-65 mm. Weight: 1300-1900 gr.
"Птицы Казахстана" том 2. "Наука". Алма-Ата, 1962.