Image A motion sensor camera captured coyotes in Pelham Bay Park in the Bronx in December 2013. Credit Gotham Coyote Project

By far the most fruitful territory has been the Bronx. In Pelham Bay Park and Van Cortlandt Park, the borough’s two largest parks, which both border Westchester, the cameras have captured images of coyote pups emerged from their dens. Residents in the Riverdale and Pelham Bay neighborhoods say they have heard the animals howling.

“We see puppies chasing butterflies in front of the camera,” said Chris Nagy, the director of research and land management at the Mianus River Gorge in Bedford, N.Y., who founded the coyote project with Mark Weckel, a conservation biologist who is the manager of the Science Research Mentoring Program at the American Museum of Natural History. “We see pairs goofing off and rolling around and playing. Sometimes you see them sniffing at the camera.”

“The finding of pups at new places is the key, but seeing them in action is really good,” he said. “They are behaving pretty naturally because the family of coyotes doesn’t know we’re taking pictures.”

The most interesting development came last year when a camera in Ferry Point Park, at the foot of the Bronx-Whitestone Bridge, recorded the first known instance of breeding so far south in the borough.

In 2012 and 2013, the camera in Ferry Point Park picked up evidence of coyotes. Last July, there were pups.

Image A statue at Van Cortlandt Park commemorating a female killed on the Deegan Expressway in 1995. Credit Richard Perry/The New York Times

“We’re not sure if they are the children of coyotes in the northern Bronx or Westchester,” said Mr. Nagy, adding that he planned to do genetic testing by analyzing the coyotes’ scat.

There is some debate among scientists about how and when coyotes arrived in New York State. One theory holds that they predated European settlers and scattered to wilderness areas in the Northeast as woodlands were cleared for farms, returning when farms reverted to forest. A more widely held hypothesis says coyotes are somewhat new to the state, having moved in from central North America only after the extirpation of the wolf by the same settlers.