Category: Falconiformes

Why the Vulture is plain colored

In the beginning, birds were created without covering. Ashamed of their long legs and ill-shaped bodies, they hid themselves among trees and rocks. They were also without song, as their throats had not yet been fitted for producing music. Long afterward, they learned their songs from whispering leaves, falling rain, running brooks and whistling winds. […]

Energetic expenditure of male Ospreys provisioning natural and manipulated broods.

Western Osprey (Pandion haliaetus) Science Article 2 abstract This study examined the relationship between brood size and energetic expenditure of male Ospreys. The daily energetic expenditure (DEE) of male Ospreys, provisioning nestlings and providing post-fledging parental care, was estimated using detailed time-energy budgets. Factors affecting DEE were investigated, and DEE and the maximum rate of […]

Courtship Feeding And Osprey Reproduction

Western Osprey (Pandion haliaetus) Science Article 1 abstract A female Osprey (Pandion haliaetus) usually is fed exclusively by its mate between pair formation and egg-laying. Laying dates and courtship periods, but not clutch size, egg size, breeding success or female weight reserves, were correlated (negatively) with the prelaying feeding rates of 12 females breeding in […]

The occurrence of fault bars in the plumage of nestling Ospreys.

Western Osprey (Pandion haliaetus) Science Article 3 abstract We document the occurrence of fault bars in a population of nestling Ospreys Pandion haliaetus under natural conditions. Ospreys had an average of 9.9 fault bars on their rectrices, however variation was large. Fault bar formation declined linearly with age and increased symmetrically from outer to inner […]