The Golden Eagle (Aquila chrysaetos) is a large raptor found across the Northern Hemisphere. With an impressive wingspan that can reach over seven feet, this formidable bird of prey possesses the speed and strength to dominate its environment. The eagle’s success is largely attributed to its highly adaptable diet that allows it to thrive across diverse habitats.
The Core Diet Small and Medium Mammals
The bulk of the Golden Eagle’s caloric intake is derived from medium-sized mammals, with a strong preference for two main groups: lagomorphs (rabbits and hares) and sciurids (squirrels and marmots). In North America, studies frequently show that mammals comprise over 80% of the eagle’s diet. These prey items typically fall within the optimal size range of 500 grams to 2,000 grams.
Specifically, the black-tailed jackrabbit (Lepus californicus) and various cottontail species are staple prey in the western United States, often making up over 75% of the items found near some nests. Beyond lagomorphs, sciurids like ground squirrels, marmots (Marmota spp.), and prairie dogs (Cynomys spp.) are heavily targeted. For example, the California ground squirrel is the primary prey in many coastal ranges, while yellow-bellied marmots are frequently taken in the Rocky Mountain regions.
Supplementing the Meal Birds Reptiles and Carrion
While mammals are the dietary foundation, Golden Eagles incorporate a variety of other food sources. Birds, such as grouse, pheasants, and various waterfowl, are regularly taken, often making up over 20% of the diet in certain regions. The eagle’s predatory focus extends to reptiles, including snakes and lizards, and in specialized locations, large reptiles like tortoises become an important seasonal food source.
The consumption of carrion, or scavenged carcasses, provides a necessary dietary buffer, particularly during the harsh winter months when small mammal activity is reduced by hibernation or snow cover. Eagles will readily feed on the remains of deer, livestock, or other large animals, which they can spot from great heights. This opportunism extends to a behavior known as kleptoparasitism, where the eagle will steal a freshly-killed meal from a smaller predator.
Specialized Hunting Techniques
The Golden Eagle employs hunting strategies tailored to the terrain and the behavior of its quarry. The eagle often begins its hunt by high-altitude soaring, using its exceptional eyesight to survey vast expanses of open ground for movement. Once a target is spotted, the raptor initiates the famous “stoop,” a high-speed, controlled dive with wings partially closed, enabling it to reach speeds between 150 and 200 miles per hour.
For smaller, colonial prey like ground squirrels, the eagle often switches to low-level “contour hunting,” flying close to the ground contours to surprise animals near their burrows. When pursuing larger prey, such as young ungulates, the eagle may use a more specialized approach, landing on the animal’s back and using its powerful talons to maintain a sustained grip until the animal succumbs. In some areas, eagles have been observed working in pairs, with one bird flushing the prey while the other waits to intercept it.
How Location and Season Influence Food Choices
The specific composition of the Golden Eagle’s diet is highly dependent on its geographical location and the time of year, reflecting its opportunistic approach to local food availability. In desert ecoregions of the southwestern U.S., the eagle’s diet may be narrowly focused on abundant desert hares and jackrabbits. Conversely, in mountainous regions or areas with different prey bases, the diet will broaden to include species like pikas.
Seasonal changes necessitate significant shifts in foraging behavior and prey selection. During the winter, when many rodents hibernate or are difficult to find under heavy snowpack, eagles are forced to rely much more heavily on carrion to sustain themselves. This seasonal shift expands the diet to include more birds and scavenged mammals. As the breeding season returns and ground-dwelling mammals become active, the eagle’s diet typically narrows again, focusing on the most energy-rich and easily accessible live prey to feed its young.