A Pair of Golden Eagles Suppling Fish as Food for Nestlings

Abstract

Video monitoring on breeding nests of a pair of Golden Eagles Aquila chrysaetos japonica in the Kitakami Mountains, Iwate, Northern Honshu, Japan, revealed that fish were supplied as food for nestlings. Fishes, totalling 57 individuals, were presented to chicks in four of the seven years analyzed, and comprised 19% of the 306 total prey animals detected. All fish were brought by the male, and most of them were removed from the nest by the female soon after, except for 10 fishes consumed by the female and nestlings. Fish supply during the nestling period was either continuous or temporary, depending on the year. Fish species could not be identified, but the variations in size, coloration, pattern and shape of fishes indicated various species were used. The method of obtaining fish was unknown, but the variation of fish species and irregular supply patterns suggested the possibility that Golden Eagles snatched prey from fish-eating birds, such as Western Ospreys Pandion haliaetus.