In Prospect Park, Dog Owners and Bird Watchers Fight for Space

About a dozen bird watchers had just crossed the ravine in Prospect Park one recent morning when a northern waterthrush, the first of the season, alighted on a faraway branch. Thirteen pairs of elbows and binoculars rose along with a ripple of delighted murmurs.

“Dog!” blurted Tom Stephenson, a warbler expert who was leading the tour, as an unleashed golden retriever, still soggy from a dip, was zigzagging his way through the line of birdwatchers’ legs. “Take a picture!”

Prospect Park’s 585 acres have always been a marvel of urban ecology, a delicate balance not just of flora and fauna, but also of  children, joggers, mountain bikers, weekend racers, Frisbee players, sunbathers, and, of course, dog owners and bird watchers.

But this time of year, between the throngs trying to glimpse the prothonotary warblers, the yellow-bellied flycatchers and other migrants making their way up the coast, and the Brooklynites trying to give their corgis and springer spaniels a few moments of freedom and fresh air, it has been difficult to find a middle ground.

The conflict, at its root, is about basic animal nature: Dogs distress birds and can trample the delicate underbrush where birds feed and nest. Bird watchers say they have been answered with exclamations of “Nazi!,” “creep!,” R-rated curses and, occasionally, “I’m going to kill you,” when asking dog owners to respect the laws, which permit untethered animals in three meadows only after 9 p.m. and before 9 a.m.

Yana Paskova for The New York TimesAn unleashed dog in Prospect Park in Brooklyn. Some dog owners say bird-watchers have aggressively confronted them and their pets there.

One birder, Adam Welz, 41, said a dog owner once got in his face, following him across the park while hurling expletive-filled insults and threats to his life.

A video shot in February captured a typical scene. A sandy-colored dog bounds into a lake, sending a gaggle of waterfowl honking and flapping.

“I got him on camera!” said a woman’s voice behind the camera.

“Doing nothing!” screamed the dog’s owner.

“Chasing the wildlife!” the woman screamed back.

Tensions have simmered for decades. Mary McInerney, who was part of the New York Council of Dog Owners Group, or N.Y.C.D.O.G, (pronounced “nice dog”), which fought to protect off-leash rights several years ago, said a bird watcher once warned her “I know where you walk. and I’ll be there waiting for you.”

“The birders aren’t just nice little old ladies and guys with binoculars,” Ms. McInerney said.

Paul Gracie â€" who comes to the park year-round to exercise his brown and white fox hound, Sammy, unlike, he pointed out, the birders who come only in the spring and the fall â€" said that when a birder told him to leash his pet because it was interrupting the migratory pattern of the birds, “I was like ‘How are birds that stupid?’”

The dogs aren’t paying attention, said Mr. Gracie, 32, adding, “If they’re just minding their own business, what’s the problem?”

What many people don’t realize, said Rob Bate, president of the Brooklyn Bird Club, is that when a canine tears through the forest understory, the delicate vegetative layer covering wooded areas, they are destroying a crucial feeding and nesting habitat for birds. At this time of year, hundreds of bird species, many whose populations are in decline, are traveling thousands of miles up the Atlantic Flyway from as far south as Chile. The city’s green spaces become essential rest stops, known as migrant traps, amid a landscape of concrete and asphalt.

“If they don’t get a chance to feed and bulk up, they may not make it to their breeding ground,” Mr. Bate said.

His club has been lobbying the city’s parks department and the Prospect Park Alliance, the nonprofit conservancy that maintains the grounds with the city, for more enforcement and for signs to mark where dogs can wander off-leash. Many of the existing placards have been torn down, Mr. Bate, 63, said. At least one has been defaced with a swastika.

The Alliance said it hoped to have new signs designed and installed in the next several weeks.

Yana Paskova for The New York TimesRob Bate, left, president of the Brooklyn Bird Club, and Adam Welz, a fellow birder, scan the trees. Mr. Bate said dogs can destroy habitats as they run through the forest understory.

The Parks Enforcement Patrol has responded with two plainclothes operations this year, said Meghan Lalor, a spokeswoman for the parks department. So far this year, the department has issued 141 dog-related summonses in Prospect Park, including for unleashed dogs, compared with 171 in all of 2013 and 59 the year before.

Ms. Lalor would not say whether the officers posed as bird watchers. “Due to the nature of the operation, and out of concern for the safety of P.E.P. officers, we can’t share more details,” she said.

A spokesman for the Police Department said they were “working with the community committee regarding the situation,” referring to a monthly meeting of groups including the Brooklyn Bird Club and Fido of Prospect Park, a group that represents the off-leash community.

Parks officers can do only so much, given that they watch over thousands of acres of woodland and public pools and beaches across the city, said Adrian Benepe, the former parks commissioner.

“Rules have been adapted and developed to take care of the greatest good,” he said, “But, by nature, they have to be somewhat self-enforcing.”

Indeed, no one with a uniform was in sight on a recent bright morning, when a great egret seemed to be posing for a photographer and two bird watchers. Its statuesque silhouette was shimmering in the surface of the Lullwater when its neck shot up. Above, a spray of robins, mourning doves, cardinals and a blue jay darted out of the trees and a cluster of warblers that had been chirping went quiet.

On the muddy pathway below, just beyond the sanctioned off-leash area, was a black-and-white Siberian husky sniffing its way along the water’s edge. The egret looked around before opening its white wings to propel itself to the other side.

A gray-haired gentleman in a Audubon-branded anorak shot the dog a stony stare as it trotted blithely out of sight. Its owner trailed several paces behind, leash dangling in hand.

Mr. Welz, who is a journalist trained in ornithology, was also taken out of the moment.

“Dog owners have been generously accommodated,” he said, “and they just abuse that. They disregard everybody else who uses the park. The arrogance is astonishing.”

Michelle Boyd, 31, who was recently in the peninsula meadow with her beagle-terrier mix, Chloe, said the birders she’s encountered can be “kind of mean.”

“If I see a bird watcher out and there’s a fork in the road,” she said, “I try to avoid them in an effort to avoid confrontation, but also to respect their space.”

A version of this article appears in print on 05/05/2014, on page A18 of the NewYork edition with the headline: In Prospect Park, a Clash of Leisure Pursuits.