Saturday, February 13, 2016

URI, DEM researchers track bobcats to assess habitat use in Rhode Island

One bobcat regularly traverses three communities in South County
A bobcat sits next to a trap in South Kingstown set by
URI and DEM researchers so they can capture and
track local bobcats. (Photo courtesy of Amy Gottfried Mayer.)

KINGSTON, R.I. – Reports of bobcat sightings have been on the increase in southern New England in recent years, but little is known about their population numbers, habitat use and prey in the region. So a team of researchers from the University of Rhode Island and the Rhode Island Department of Environmental Management has undertaken a five-year effort to trap and track bobcats to better understand their ecology.

The scientists, led by URI Professor Thomas Husband and RIDEM Wildlife Biologist Charles Brown, captured one bobcat at URI’s East Farm in November and fitted it with a GPS collar that enables the researchers to track its movements every day for about a year.

According to Brown, the collar collects data on the bobcat’s location every two hours. It also transmits a signal to a hand-held receiver, allowing the researchers to follow it from a distance. When the researchers get within 100 yards of the animal, they can download the GPS data, which they do every week. 

“This bobcat is wandering a lot farther than we expected,” said Brown. “We’ve tracked him to Snug Harbor, Bonnet Shores, Matunuck, Charlestown. We’ve lost track of him for a few days at a time as he wanders, but we always catch up to him.”

Bobcats are the most widely distributed feline in North America, where they live in deserts, mountains, prairies and coastal regions. Weighing up to 35 pounds, they eat a wide variety of small mammals and other prey. In Rhode Island they are believed to consume mostly rabbits, squirrels and rodents.

The animals have been sighted in nearly every community in mainland Rhode Island. The hotspots seem to be in South Kingstown, Westerly and Foster, but they are also known to travel through densely populated areas of Cranston, Warwick and West Warwick.

URI Research Associate Amy Gottfried Mayer is responsible for the day-to-day monitoring of the collared bobcat, as well as for ongoing efforts to capture additional bobcats in box traps. She maintains up to 10 traps distributed in the southern portions of South Kingstown, which she baits with dead ducks, rabbits, squirrels and other animals. She opens the traps every Monday, checks them each weekday morning, then closes the traps on Friday.

Mayer said the animals are turning out to be very difficult to trap. She uses a variety of visual and scent lures to attract the animals to the trap, but so far just the one animal has entered and been captured. Yet she knows that bobcats have come close. 

At each trap, a motion-sensing camera takes pictures of any animal that approaches. At one site the camera recorded three young bobcats sniffing the trap, while two different adult bobcats were photographed at another trap. The collared bobcat has also been photographed at a trap. And one bobcat even put its head and foot in a trap. But no others have entered the trap completely.

Brown says that it is difficult to get a bobcat to enter a confined space, but he believes that their hesitancy to enter the traps also has a great deal to do with the weather.

“The weather has been warm this winter, so they probably have easy access to food,” he said. “They haven’t reached the point yet when they’re really hungry. I think we’ll have better luck in harsh weather when it’s harder for them to find prey. But for now we’ll just do our best to keep the traps visually appealing.”

That’s not to say that the traps haven’t caught anything. Mayer has released gray foxes, fishers, a red-tailed hawk and several opossums from the traps, but no more bobcats. She and Brown have even reached out to trappers and other bobcat researchers to learn their favorite capture techniques, but still to no avail.

“We’ll keep playing around with the traps, experimenting with different lures and set-ups,” Mayer concluded. “We know they’re here, so we’ll just keep on trying.”