White-tailed eagles, also known as sea eagles, are opportunistic feeders that consume a varied diet. They primarily feed on fish and water birds, but they also consume small mammals and carrion, which are the carcasses of dead animals. Carrion can make up a significant portion of their diet, especially during the winter months.
The Diet of White-Tailed Eagles
The diet of white-tailed eagles varies depending on the location of their nests. Along the coast, seabirds and fish make up most of their food remains, while at nests further inland, wetland birds and rabbits are more common. As white-tailed eagles continue to recolonize historic territories away from the coast, species such as mountain hares and freshwater fish are likely to become important food sources.
Carrion in the Diet of White-Tailed Eagles
In Scotland, a study of 92 nest sites revealed that 67% of the food items were birds, 27% were mammals, and 6% were fish, with seabirds and fish being the most important food source. The study also found that only 6% of the food items were mammals, and lambs made up a very small proportion of these mammalian food items.
In Germany, a study showed that carrion accounted for almost 30% of the white-tailed eagle diet in winter. In Denmark, white-tailed eagles regularly search tidelines for washed-up dead fish, birds, and sea mammals. In the Solent and surrounding area, foraging eagles will take any washed-up dead fish or marine mammals as they search shorelines for food.
Scavenging Versus Predation
White-tailed eagles are known to occasionally eat lambs, but most of these instances involve scavenging carrion rather than preying on live animals. The study of 92 nest sites in Scotland found that seabirds and fish were the most important food source for white-tailed eagles, making up 67% of the food items.
Factors Affecting the Diet of White-Tailed Eagles
Image source: white tailed eagle by Andreas Weith
The diet of white-tailed eagles can be influenced by several factors, including:
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Location of Nest: As mentioned earlier, the location of the nest can affect the diet of white-tailed eagles. Coastal nests tend to have a higher proportion of seabirds and fish, while inland nests have more wetland birds and small mammals.
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Availability of Food Sources: The availability of different food sources can also influence the diet of white-tailed eagles. For example, if there is a high abundance of fish or seabirds in a particular area, the eagles may focus more on these food sources.
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Seasonal Changes: The diet of white-tailed eagles can also change with the seasons. During the winter months, when other food sources may be scarce, the eagles may rely more heavily on carrion and scavenging.
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Recolonization of Historic Territories: As white-tailed eagles continue to recolonize historic territories away from the coast, their diet may shift to include more freshwater fish and small mammals, such as mountain hares.
Conclusion
In summary, white-tailed eagles are opportunistic feeders that consume a varied diet, including fish, water birds, small mammals, and carrion. Carrion can make up a significant portion of their diet, especially during the winter months. The specific composition of their diet can vary depending on the location of their nests, the availability of food sources, and seasonal changes. As white-tailed eagles continue to recolonize historic territories, their diet may evolve to include new food sources, such as freshwater fish and small mammals.
