After two years of studying urban foxes in Charlottetown researchers at UPEI say the population is well established, growing, and permanent.

With help from members of the public, who have been reporting sightings through a web site, Marina Silva-Opps's team has been tracking foxes in the city for two years. The project recently recorded its 2,500th sighting.

The researchers identified 42 active fox dens in the city of Charlottetown last year, and believe there are even more. Each spring each active den could become home to an average of four new pups. That means at least 160 new foxes were likely born and raised in the city.

Researchers have used the sightings data to create a map of the places where you may most likely see a fox.

While there have been concerns the foxes are thriving because people are feeding them, the researchers say that makes up only a small part of the urban fox's diet.

Bird feeders, says Silva-Opps, provide a food resource for foxes in a number of ways.

Marina Silva-Opps - custom

Foxes are opportunistic feeders, says UPEI researcher Marina Silva-Opps. (CBC)

"It could be because they are going for the seeds, because foxes are very opportunistic and very generalist in what they eat," she said.

"Also probably for the birds, and maybe for the rodents that go after the seeds."

The presence of foxes in backyards can be a concern. Researchers have found fox droppings could be a source of worms or other parasites which could be transmitted to dogs, or even humans.

While acknowledging potential problems, the researchers say the foxes are so well-established there is no way of getting rid of them now.

"We have to learn to live with them," said Silva-Opps.

"We have to learn to respect the space between us and them, and we have to learn to manage the population by reducing the resources that are available to them."

Silva-Opps said there is a lot more to learn about urban foxes, and the research will continue.