Golden eagle
Longevity
Natural sources of mortality are largely reported in anecdotes. On rare occasions, golden eagles have been killed by competing predators or by hunting mammalian carnivores, including the aforementioned wolverine, snow leopard, cougar, brown bear and white-tailed eagle attacks. Most competitive attacks resulting in death probably occur at the talons of other golden eagles. Nestlings and fledglings are more likely to be killed by another predator than free-flying juveniles and adults. It has been suspected that golden eagle nests may be predated more frequently by other predators (especially birds, which are often the only other large animals that can access a golden eagle nest without the assistance of man-made climbing equipment) in areas where golden eagles are regularly disturbed at the nest by humans. Jeff Watson believed that common raven occasionally eats golden eagle eggs but only in situations where the parent eagles have abandoned their nesting attempt. However, there are no confirmed accounts of predation by other bird species on golden eagle nests. Occasionally, golden eagles may be killed by their prey in self-defense. There is an account of a golden eagle dying from the quills of a North American porcupine (Erethizon dorsatum) it had attempted to hunt. On the Isle of Rùm in Scotland, there are few cases of red deer trampling golden eagles to death, probably the result of a doe having intercepted a bird that was trying to kill a fawn. Although usually well out-matched by the predator, occasionally other large birds can put up a formidable fight against a golden eagle. An attempted capture of a great blue heron by a golden eagle resulted in the death of both birds from wounds sustained in the ensuing fight. There is at least one case in Scotland of a golden eagle dying after being “oiled” by a northern fulmar, a bird whose primary defense against predators is to disgorge an oily secretion which may inhibit the predator's ability to fly. Of natural sources of death, starvation is probably under-reported. 11 of 16 dead juvenile eagles which had hatched in Denali National Park had died of starvation. Of 36 deaths of golden eagles in Idaho, 55% were possibly attributable to natural causes, specifically 8 (26%) from unknown trauma, 3 (10%) from disease and 6 (19%) from unknown causes. Of 266 golden eagle deaths in Spain, only 6% were from unknown causes that could not be directly attributed to human activities. Avian cholera caused by bacteria (Pasteurella multocida) infects eagles that eat waterfowl that have died from the disease. The protozoan Trichomonas sp. caused the deaths of 4 fledglings in a study of wild golden eagles in Idaho. Several further diseases that contribute to golden eagle deaths have been examined in Japan. A captive eagle died from two malignant tumors – one in the liver and one in the kidney.
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