Wild animals are flocking to backyards for food and shelter, according to a new study from NC State University. The research explains why animals are sometimes more abundant and diverse in the suburbs than they are in the wilderness.
Study co-author Roland Kays is an associate professor at NC State and the director of the Biodiversity & Earth Observation Lab at the NC Museum of Natural Resources.
“They’re using the gardens a little bit, they’re using the brush piles a little bit, and they’re using the water features, but feeding has the most dramatic influence on animal activity in the backyard,” said Professor Kays.
The researchers set out to investigate what is known as the “urban wildlife paradox.” Even though human development is generally associated with biodiversity loss, scientists have found that moderately developed areas frequently host a variety of mammals compared with wild areas.
“There’s this idea that nature and humans don’t coexist well,” said Professor Kays. “But what we’ve been finding is that when it comes to mammals, especially in North America, they actually do pretty well around people. You end up with high abundance. You expect there to be fewer animals, and there’s actually more.”
To examine whether food and shelter attract animals in suburban areas, the researchers set up cameras in the backyards of 58 homes near Raleigh, Durham, and outside of Chapel Hill. For comparison, the team set cameras up in nearby forests, rural, and urban areas.
In collaboration with experts at the University of Montana, the researchers analyzed the images. They identified seven species – squirrels, gray and red foxes, Virginia opossums, eastern cottontail rabbits, woodchucks, and eastern chipmunks – that were more frequently seen in yards compared to forests. In addition, animals such as white-tailed deer, squirrels, and raccoons were found to be more common in suburban forests compared to rural ones.
“This basically confirmed the urban-wildlife paradox, showing that some species are more abundant in yards,” said Professor Kays. “It’s not a big surprise if you live in the suburbs – you see the animals. It’s the squirrels, raccoons, deer and opossum.”
Feeding animals, particularly with birdfeeders, had the strongest influence on the abundance of animals in a yard. For example, eastern gray squirrels were more common at feeders than in suburban or rural forests. Cottontail rabbits, raccoons, and opossums were also frequently spotted at birdfeeders.
“This supports the idea that direct human subsidies are a big part of the explanation for the urban-wildlife paradox,” said Professor Kays. “It shows that individual decisions by homeowners and private property owners can have a big impact on the wildlife in the backyard and living in the area.”
According to Professor Kays, the findings raise questions about what homeowners should do, and whether attracting wildlife is good or bad.
“You see widespread recommendations: Don’t feed the bears. Where do you draw the line from small birds to squirrels, rabbits and raccoons? When does it become bad to feed the animals, even if you’re doing it accidentally?”
“On one hand many people enjoy having wildlife around and they can help support a healthy local ecosystem; however, they could cause conflict with people.”
The study is published in the journal Frontiers in Ecology and Evolution.
By Chrissy Sexton, Earth.com Staff Writer