Bald Eagles Are Back. And They Want to Eat Your Pets.

With an 8-foot wingspan and a distinctive snowy-white head, America’s national emblem conjures feelings of patriotism and reverence.

“You’re in awe every time you see one,” says Jeanine Pesce, who recently moved from New Jersey to British Columbia and now sees the raptors almost daily. “Their physicality and presence is so profound you feel a need to pay homage to them.”

But Ms. Pesce, who owns a consulting agency, has had to explain some National Geographic-worthy encounters to her 5-year-old daughter. “One day I watched an eagle drag a Canadian goose back and forth across rocks for hours,” she says. “I was told that’s how they tenderize their meat.”

It wasn’t long ago that birdwatchers considered the odds of a bald eagle sighting just this side of a unicorn sighting. Through conservation efforts and the banning of chemicals like DDT, the population recovered to numbers that warranted the bird’s removal from the endangered species list in 2007. A recent report from the U.S. Fish and Wildlife Department found that numbers have quadrupled to more than 316,000 in 2019, from 72,000 in 2009.

Those numbers only reflect populations in the lower 48, notes Myles Lamont, a biologist with the Hancock Wildlife Foundation, a nonprofit in Surrey, British Columbia that promotes the conservation of wildlife, particularly the bald eagle, and its habitat. “If you factor in the populations in Alaska and Canada you add at least another 150,000 or more birds.”

The spike in numbers has prompted joy among animal-lovers—and anxiety among others. Owners of small pets have outfitted little dogs and cats in spiked collars and armor-like vests to keep them from becoming bird food.

“Eagles are strong enough to carry a 12-pound salmon, so a four-pound dog is nothing,” says Mark Robokoff, owner of AK Bark pet shop in Anchorage. His shop sells CoyoteVest, a protective jacket covered in Kevlar and spikes, intended to protect small pets from coyotes. Mr. Robokoff immediately recognized its potential in a state with an estimated 30,000 bald eagles. The vest is topped with bright red nylon whiskers which he says scare off the birds from above.

Tom Abraham, a Nelson, British Columbia-based trip planner with active travel company Butterfield & Robinson, has had to worry about bald eagles stalking his lambs and his daughter’s chickens.

“We lost one [chicken] to an eagle last year,” he says. “I string flags overhead to create an obstacle. It gives the chickens more time to take cover.”

The birds can also make quite a mess.

Maureen Gordon,

manager of Maple Leaf Adventures, an ecotour company that runs trips in Alaska and British Columbia, says bald eagles love to perch in the masts of her company’s schooner. “Guests marvel, and the birds are stunning, but they’re also quite a hazard for our deck and sometimes our clients,” she says. “As soon as the birds fly, watch out below, because they poo.”

Bald eagles aren’t the only birds of prey best admired from a distance.

Cinda Mickols recently had around 15 endangered California condors trash the back deck of her Tehachapi, Calif. home.

“I’m 68 and barely 5-foot-3, and these birds are enormous,” she says. “At first I was scared, but then I saw that they had pecked apart the cover of my hot tub. I started waving my cane and yelling, ‘The party is over’ until they flew away,” she says.

Ms. Mickols says she has no idea why the condors prefer her deck, but they come like clockwork at 6:30 p.m. “I joke that it’s cocktail hour,” she says. “Their poo stains the deck and I worry their talons have punctured my roof, but I can’t get mad because they need protection. And I’ve started to think of them as angels watching over me.”

She’s reached out to authorities and researchers to try to learn more about the birds so she can live alongside them. “I was told it’s OK to spray them with water,” she says.

Ms. Pesce in Vancouver says that while the bald eagles have provided her with a movie theater’s worth of entertainment in her backyard, they’ve also supplied her family with an education about the less glamorous side of the magnificent bird.

“It’s like watching the cycle of life happen,” she says. “And my takeaway is that I would not want to come back as an eagle. They may be at the top of the food chain, but they get no peace being followed around all day by seagulls and crows chasing their scraps.”

Write to Jen Murphy at workout@wsj.com