This bald eagle gazes warily into the distance while clutching its freshly caught fish. At least in the wintry north-west of the USA this is now a rare sight, because there the eagles sometimes had to find new food sources – to the delight of the dairy farmers.
In the past, the Nooksack River in Washington state provided the bald eagles with a bountiful buffet of salmon every winter. The fish spawned, died, and washed up on shore for the eagles to eat. However, due to climate change, salmon are now spawning earlier, precisely when the river’s annual flood is at its peak. The dead fish therefore no longer land on the shore, but are washed away.
The white-tailed eagles living in this area therefore had to find new sources of food for the winter and moved their search for food from the rivers to the fields. They now hunt small mammals there instead of fish, but they don’t spurn carcasses or other meat-based food either. At least on the land of the dairy farmers, they are therefore welcome. “Many farmers value the services the eagles provide, such as removing carcasses and pests,” said Ethan Duvall of Cornell University, who and his team researched the symbiotic relationship between eagles and dairy farmers.
In the winter, the bald eagles now feed, among other things, on the waste products of the dairy farms, such as organic waste resulting from the birth and death of cows. They also kill waterfowl, rodents and starlings, which would otherwise be agricultural pests and devour the fields. This “win-win situation” gives Duvall hope that farmers and conservationists could work together to protect wildlife in the future.