In Brooklyn Park, a Fierce New Pecking Order

Ken Ruinard/Anderson Independent, via Associated Press A mockingbird feeds her hatchling. The birds respond promptly and aggressively to perceived threats to their young, as humans in Brooklyn are learning.

A two-ounce menace is terrorizing Greenpoint, Brooklyn.

On Arthur Henry's inaugural stroll through the recently opened Transmitter Park along the waterfront on a piercingly bright afternoon last week, he felt a slight tap on his head.

He reached up, touched blood, and then saw a mockingbird circling above.

Mr. Henry ran.

Two days later, on his next visit to the park, he heard “a wail, like a battle cry,” emanating from what he believed was the same bird, as it plunged toward him once again.

“It's so ridiculous,” said Mr. Henry, 44, a children's book author, as he showed a reporter the site of the attack last Thursday. “I'm scared of a bird.” He had brought along Ray-Bans to protect his eyes should the bird come back for a third round.

Also last week, Pacifico Silano, an artist from Williamsburg, was sunbathing with a friend at the park (officially known as WNYC Transmitter Park because it was built on the former site of WNYC's radio towers) when a frantic woman with two small dogs approached.

“She was like, ‘Be careful. There's this bird hanging out over there and it's attacking me,'” said Mr. Silano, 27. “I was like, ‘Are we really having this conversation?'”

Such aggressive behavior in mockingbirds result from perceived threats to their hatchlings, said Glenn Phillips, executive director of New York City Audubon. The incidents should stop any day now as nesting season ends, he said.

“Once the young fledge, they'll settle down,” Mr. Phillips said.

Mockingbirds have thrived in New York City since immigrating to the region in the 1960s, drawn by ornamental fruiting plants that provide a winter food source, Mr. Phillips said. They have a reputation for keeping New Yorkers up at night mimicking car alarms and for sporadically assaulting pedestrians.

Angela Golinvaux, a 30-year-old salesclerk from Bushwick, also felt the sting of a pointy black beak recently, near the Kent Street entrance to the park where she usually eats her lunch.

“I had my hair up in a bun and I felt something hit it and I was like, ‘What the heck?'” she said.

The next day, also on her lunch break, multiple mockingbirds greeted Ms. Golinvaux mid-trek to the waterfront. (Scientists have found that mockingbirds can recognize humans who have previously been identified as threats.)

“They were dive-bombing me, and flying at me, and perching and looking at me,” she said, describing behavior known as mobbing that is not uncommon in small birds, according to Mr. Phillips.

She screamed expletives back at the birds and bolted toward West Street, shouting, “This isn't your block!”

The birds, at least for the time being, may disagree.