Dog’s are a human’s best friend—and a shorebird’s worst enemy

This article is from Hakai Magazine, an online publication about science and society in coastal ecosystems.

Kit saw the ocean for the first time on an iron-skied February afternoon. My wife and I had spent the last three years in eastern Washington State, a region landlocked by 600 kilometers of forests, sagebrush, and wheat fields. For most of that time, we’d cohabited with Kit, an affectionate piebald mutt we’d adopted from a local shelter. Now we were moving to another inland environment—Colorado—via a circuitous road trip that took us through San Francisco. Our brief time in California, we realized, might be Kit’s first and last chance to lay her protuberant eyes upon the sea.

We drove to an ocean beach that some literal-minded city father had named Ocean Beach. I walked Kit onto the damp sand and watched her scrape at the stuff, as though trying to find its bottom. I unclipped her leash and Kit began to saunter, then run, one step ahead of the frothy surf, like a sandpiper. The wind pinned her floppy ears against her head, and she flung herself down to roll ecstatically in some dead washed-up thing. She looked happy; she looked free; she looked right.

In that, Kit wasn’t alone: most dogs love the beach. But the beach doesn’t love our dogs. A growing body of literature suggests that Canis lupus familiaris has become a significant force of disturbance along the world’s shorelines—not just the packs of feral dogs who roam some less regulated shores, but the domestic pooches whose well-meaning owners, like me, turn them loose for a romp in the sand. Dogs have been known to maul seal pups, outcompete eagles for dead fish, and dig up turtle nests. They save their worst harms for shorebirds, killing chicks, crushing eggs, and forcing migrating birds to burn more calories than they can spare. “Man’s best friend,” researchers concluded in 2011 with typical scientific understatement, “may not be wildlife’s best steward.”

In response to these harms, coastal managers have implemented leash laws, seasonal restrictions, and even outright dog bans. But limiting when and where our mutts can move invites controversy. After politicians enacted a partial dog ban on one Australian beach, aggrieved pet owners claimed that they’d become “criminals in [their] own backyards.” Others gripe that even strict laws are rarely enforced: in San Diego, where beach dogs are subject to a passel of regulations, vigilantes seem to take perverse pleasure in videotaping scofflaws. While our pets are the nominal causes of these conflicts, however, the real culprits aren’t Akitas and Airedales, but us—and our mastiff-sized blind spots around our furry family members. The dogs, of course, are just being dogs.

When we think about destructive pets, cats come first to mind. Whether feral or free-range, cats are swift, silent assassins, responsible for the deaths of up to four billion birds and 22 billion mammals each year in the United States alone. Dogs, by contrast, seem more goofy than lethal, hilariously distant from their wolfish origins. (Does a Shih Tzu really strike terror in any other animal?) In The World Without Us, author Alan Weisman postulated that, should humankind abruptly disappear, cats would fare just fine. Dogs, however, would vanish alongside their people, unable to survive without their twice-daily bowls of kibble.

Yet dogs, the world’s most abundant carnivores, exert immense impacts in their own right. In Mongolia, they kill antelopes and gazelles; in New Zealand, they’ve hampered the recovery of imperiled kiwis. Australian researchers have shown they scare off enough animals to “cause a depauperate local bird fauna.” In Russia’s Lake Baikal, they once transmitted a deadly virus to freshwater seals.

In 2019, on a reporting trip to Tasmania, Australia, I heard a firsthand account that exemplified the dangers of dogs. One evening, I met up with the founder of a group devoted to safeguarding the colonies of little blue penguins that nest along the state’s north coast. As we watched penguins—stout as bowling pins, feathered in glossy indigo, plump with sardines—waddle ashore after several days at sea, the advocate outlined the measures he’d taken to protect his beloved birds. He had erected fencing along a coastal highway to keep them from wandering into traffic and cleaned hundreds of the birds after a tanker ran aground and befouled the beach with oil. Yet he felt powerless to save penguins from the domestic dogs that occasionally escaped their owners, wandered down to the beach, and, on stumbling upon such vulnerable prey, instinctively began to slaughter. (Even friendly dogs can kill: penguins are so easily stressed that “playing” with them can induce cardiac arrest.) The year I visited, six separate dog attacks on four colonies had claimed the lives of more than 250 penguins.

“We don’t have dog attacks in Tasmania—we have dog massacres,” the group’s leader, who asked to remain anonymous for fear of reprisal from local dog owners, told me. “It takes two to 10 minutes for a dog to kill 40 or 50 penguins.”

Granted, little blue penguins are uniquely easy victims; not even the fastest greyhound is likely to catch an adult gull or dunlin. But the mere presence of dogs is enough to send birds into flight: after all, what’s a poodle but an unusually curly-haired fox, coyote, or wolf? In Chile, scientists have observed dogs pursuing whimbrels, a graceful shorebird that probes mudflats with a long, curved bill. On Mediterranean beaches, dog walkers flush plovers from their nests far more often than humans alone, exposing eggs to predators and thermal stress.

“Certain dog owners seem not just to allow it, but to take their dogs to the beach so that they can chase birds,” says David Newstead, bird program director at the Texas-based nonprofit Coastal Bend Bays and Estuaries Program. “These are otherwise conservation-minded people.”

Hounding birds on the beach seems like a benign behavior, or even a wholesome form of play: picture a euphoric golden retriever, tongue lolling and paws kicking up sand, merrily dispersing a flock of terns into a summer sky. Yet even a few brief flights can have big impacts. On the Gulf Coast beaches where Newstead works, many shorebirds are migrants—red knots, piping plovers, sanderlings—who have come to Texas to refuel during epic transcontinental journeys. They spend their days alternately resting and gorging on marine invertebrates, a cycle that’s critical to building the energy stores that migration requires. Dogs disrupt this loafing and feeding, leaving birds less equipped to complete their voyages.

“Every time you’re forcing birds to fly down the beach, the gas tank is going toward empty,” Newstead says. “If they can’t take in more energy than they’re expending on that beach, they’re eventually going to leave. It’s functional habitat loss.” When Newstead gently reprimands dog owners, he appeals to analogy and sympathy: imagine you’ve just gotten home from work and want nothing more than to chill on the couch with a beer—and then a pack of barking dogs tears into the house and chases you outside, over and over again. “Sometimes they grudgingly put their dog back on a leash,” he says. “Sometimes they just say to hell with you.”

Dogs also disturb ecosystems in stranger, subtler ways. In the fall of 2020, Brooke Maslo, an ecologist at Rutgers University in New Jersey, embarked on an ambitious study of how coastal scavengers dispose of carrion. She and her collaborators set out motion-activated cameras on beaches along the Jersey Shore, then baited each with three fish carcasses acquired from tackle shops. “They would always get a big kick out of it,” Maslo says. “‘What do you want 150 dead menhaden for?’”

Maslo’s intent wasn’t to study dogs—it was to monitor the wildlife that came to beaches to feed, from red foxes and raccoons to corvids and laughing gulls. Yet dogs inevitably appeared. Sometimes Maslo’s cameras caught owners dragging their pooches away from the dead fish or placing the carcasses back on the ground, presumably after prying them from their pets’ jaws. More often the dogs urinated or defecated around the menhaden, as though claiming the carrion as their own.

At first, Maslo admits, the constant canine presence was frustrating: here she was, trying to document wild scavengers, and her cameras were clogged with domestic ones instead. As she watched more videos, though, a pattern emerged: When dogs appeared during the day, other scavengers steered clear that night, likely scared off by the scent-marking of an apex canid. Raccoons, skunks, and grackles were completely absent from dog-infested beaches, and foxes, black-backed gulls, and ghost crabs were rare. Maslo and her colleagues observed last year in Scientific Reports that nocturnal scavengers took 34 percent longer to find the dead fish after dogs had come around and ate far smaller portions when they finally showed up.

Why does this matter? Coastal necrophages play a crucial and salutary role, consuming the dead and thus preventing beaches from being strewn with carcasses. What’s more, Maslo says, mobile scavengers like gulls distribute carrion across beaches, spreading out nutrients and thus supporting ecosystems—not unlike dying salmon gifting their nitrogen and phosphorus to the forests in which they spawn. By claiming beaches for their own, dogs inhibit this breakdown and dispersal. You might not find a dachshund particularly intimidating, yet our pets are creating landscapes of fear, monopolizing food sources, and disrupting life’s fundamental processes.

In fairness, coastal managers aren’t blind to dogs’ impacts. Not long after I visited Tasmania, the state government raised the fines for owners whose dogs entered penguin colonies more than 20-fold, a measure that dramatically reduced the rate of attacks. Still other beaches require dogs to be leashed, restrict the hours in which they’re permitted to run loose, or are altogether dog-free. Oregon, for instance, bars even leashed dogs from snowy plover nesting grounds between March 15 and September 15. After an off-leash dog killed a piping plover chick in Scarborough, Maine, in 2013, the town hired plover police to post signs and educate beachgoers about leash laws. “I was expecting to be getting a lot more negativity,” a plover cop cheerfully told reporters.

But Scarborough’s plover guards are more exception than rule—for when dog regulations arrive, controversy usually follows. Few people know that better than Karen Harper, a councilor in Saanich, a municipal district on Vancouver Island, British Columbia. For years Harper had fielded complaints from coastal homeowners who’d witnessed dogs harassing wildlife and people along Cadboro Bay, an inlet whose beaches lie within a federal bird sanctuary. Although Canadian law prohibited off-leash dogs in the sanctuary, Saanich’s own regulations permitted them. In early 2020, Harper, hoping to resolve the contradiction, formally requested that Saanich’s staff study dogs’ impacts and review its bylaws.

“And then,” she says, “all hell broke loose.”

Angry emails poured into the council: Saanich residents urged Harper to “stop wasting staff time,” called her concerns “unfounded and largely irrelevant,” and described her request as “bogus procedure.” (Other commenters applauded Harper for confronting the degradation of “precious and priceless natural areas.”) On Facebook, Harper says, residents derided her as a “dog hater,” though she’d long owned dogs, most recently a pair of German shepherds. One local had dog feces flung into her yard. The situation got so volatile that animal-control officers started going to the beaches in pairs.

Harper was grappling with a persistent conundrum in coastal management: we know a lot more about how dogs harm beaches than how to get people to rein in their pets. In one typical study, researchers in southeast Australia found that just one-third of dog walkers felt “strongly obliged” to leash dogs. “While wildlife protection is important to dog owners,” the scientists added, “greater importance is given to the benefits of unleashed exercise for dogs.” Per one survey, 85 percent of American dog owners consider their pets part of the family; no wonder we privilege our own animals’ happiness over the welfare of wild creatures.

Other scientists have sought the answer in one of humanity’s most powerful motivators: peer pressure. In 2018, researchers interviewed nearly 900 coastal dog walkers in Maine, New York, and South Carolina. People didn’t just let their dogs roam free to exercise and sniff other mutts, they realized, but because social and personal norms sanctioned it. To change the attitudes of dog owners, the researchers proposed modeling different behavioral norms. Perhaps a group of volunteers could parade Spot and Rex around on leashes, each dog outfitted with a vest that reads “This Dog Shares the Shore with Shorebirds.” Social media loves nothing so much as a puppy (well, aside from a cat); maybe #ThisDogSharesTheShore will someday go viral on Instagram.

Still, the most sure-fire solution to averting dog conflict is also the most draconian—an outright ban of even leashed dogs. “Canadians are theoretically compliant types, but if you have leash-only areas, people ignore it,” Harper says. “It’s kind of discouraging.” The temptation to let dogs run free may be irresistible; better, perhaps, to proscribe our pooches altogether.

Ultimately, it’s hard not to conclude that the furor over dogs is a red herring—for the real problem isn’t our mutts, but our cognitive dissonance. Just as we forgive the foibles of our human relatives, we ignore the casual harm wrought by our four-legged children. (“Sure, those other dogs might chase birds, but my Duke would never hurt a fly.”) Perhaps because our dogs’ behaviors are a direct reflection of us, we harbor the delusion that they’re under our control; I recently saw an off-leash collie take a healthy bite of a jogger’s butt, even as the animal’s owner yelled at her to stand down. We rationalize their misdeeds, overrate their training, prioritize their pleasure over other beings’ right to exist. Love is not only blind, it’s blinding.

Much though I believe in protecting the natural world from our pets, I’m as guilty of this myopia as anyone. Earlier this winter, a year after Kit experienced the Pacific Ocean, I took her skiing near our new home in Colorado—unleashed. For a few minutes she trotted beside me, sniffing scat and eyeing squirrels, and, as always, I felt joy to see her happy and stimulated. Then she veered into a jumble of windblown logs and scrabbled at the snow with her paws. I slogged over and dragged her away, but it was too late; she’d unearthed and killed a hibernating vole, soft and warm as a newborn’s cheek. I felt grief, then momentary anger at Kit, but it wasn’t her fault—she was merely doing what her ancestors had been bred to do. The responsibility was entirely mine.

This article first appeared in Hakai Magazine and is republished here with permission. Read more stories like this at hakaimagazine.com.