As a result of a weak, late-season chum salmon run, thousands of bald eagles that normally feed on salmon in rivers from Alaska to British Columbia are starving and forced to scavenge landfills to survive.
The birds depend on late fall runs of chum, the last salmon species to spawn each year, to carry them through the winter. But the 2010 chum run was much lower than usual, and not enough to sustain the eagles through periods of scarcity.
David Hancock, biologist, author, and founder of the Hancock Wildlife Foundation, says the eagles have few alternative food sources this time of year and are in the most desperate situation he’s seen in over 40 years of studying west coast wildlife.
“The alternatives, if the salmon aren’t there, are not very good for the eagles. There’s just nothing else, so they move into the local refuse and landfills. On one day, we had 1,387 eagles at the landfill—they were in desperation,” he says.
About 7,200 bald eagles that descended near Chehalis River in the southwest corner of British Columbia quickly exhausted the salmon supply, Hancock says. Just 10 days later the eagle population was reduced to 348 as they dispersed to find other food sources.
He says many eagles have resorted to “stealing” food from gulls and other birds at landfills in greater Vancouver, affecting these species as well. Compounding the problem is an especially cold winter that puts additional stress on their fight to survive.
The hardest hit are young eagles that haven’t yet reached adulthood. Eagles don’t learn hunting skills until they are about three years old, so largely depend on food sources that are already deceased. Chum is an ideal food source because the salmon die naturally after spawning.
The birds depend on late fall runs of chum, the last salmon species to spawn each year, to carry them through the winter. But the 2010 chum run was much lower than usual, and not enough to sustain the eagles through periods of scarcity.
David Hancock, biologist, author, and founder of the Hancock Wildlife Foundation, says the eagles have few alternative food sources this time of year and are in the most desperate situation he’s seen in over 40 years of studying west coast wildlife.
“The alternatives, if the salmon aren’t there, are not very good for the eagles. There’s just nothing else, so they move into the local refuse and landfills. On one day, we had 1,387 eagles at the landfill—they were in desperation,” he says.
About 7,200 bald eagles that descended near Chehalis River in the southwest corner of British Columbia quickly exhausted the salmon supply, Hancock says. Just 10 days later the eagle population was reduced to 348 as they dispersed to find other food sources.
He says many eagles have resorted to “stealing” food from gulls and other birds at landfills in greater Vancouver, affecting these species as well. Compounding the problem is an especially cold winter that puts additional stress on their fight to survive.
The hardest hit are young eagles that haven’t yet reached adulthood. Eagles don’t learn hunting skills until they are about three years old, so largely depend on food sources that are already deceased. Chum is an ideal food source because the salmon die naturally after spawning.
When eagles don’t get enough food they become lethargic, and low energy levels makes it hard for them to fly or even generate enough body heat to survive.
According to Hancock, over-harvesting has led to the decrease in chum salmon, which triggered a chain reaction among eagles and throughout the ecosystem.
“The bottom line is eagles are not doing well, but it’s not just the eagles, it’s the environment that produces them. It didn’t produce the food supply—the fish—to feed the rivers, to feed the bears, the wolves, and the eagles. And that’s a long-term problem that we have to solve. We are over-utilizing the resources of the land, at great cost.”
This week the eagles will be heading to the east coast of Vancouver Island in hopes of feeding off the herring run that starts in early March. But Hancock says it will be too little too late for many of them.
“Right now the challenge is for all these young birds to move toward where the herring are, but there’s almost no herring left on the coast of British Columbia. We’ve just so over-harvested for 40–50 years that they’re decimated as well. [So] the next saving grace that would’ve tided the eagles over is not a rosy picture either.”
Bears have been negatively impacted as well. The North Island Wildlife Recovery Center in Errington, British Columbia, has reported an increase of starving bear cubs. Lack of pink and chum salmon, as well as failed berry crops, have been named by conservationists as factors in their unusually low weight.
Robin Campbell, the center’s wildlife manager, says almost all cubs coming into the center weigh between 9 and 16 kilograms (2–35 lbs). Normally they should weigh between 27 and 36 kg (60–80 lbs) before going into hibernation.
“This is totally unusual. We’ve never had this happen before,” he told The Montreal Gazette.