Golden eagle
The golden eagle ("Aquila chrysaetos") is one of the most powerful predators in the avian world. One author described it as "the pre-eminent diurnal predator of medium-sized birds and mammals in open country throughout the Northern Hemisphere". Golden eagles usually hunt during daylight hours, but were recorded hunting from one hour before sunrise to one hour after sunset during the breeding season in southwestern Idaho. The hunting success rate of golden eagles was calculated in Idaho, showing that, out of 115 hunting attempts, 20% were successful in procuring prey. A fully-grown golden eagle requires about of food per day. In the life of most eagles, there are cycles of feast and famine, and eagles have been known to go without food for up to a week. Following these periods without food, they will then gorge on up to at one sitting. The powerful talons of the golden eagle ensure that few prey can escape them once contact is made. The talons of this species exert approximately of pressure, around 15 times more pressure than is exerted by the human hand, although some claim that the largest individual females may reach a pressure of . Few other large raptors have been tested in their foot strength, though the huge harpy eagle, when tested, exerted a psi approximately greater than the tested golden eagle. It has been claimed that the golden eagle can lift more than its own body weight in flight. However, other sources claim that a hare, marmot or deer calf weighing is a struggle for even a large female to carry and that prey much over would require favorably high wind conditions.