An endangered rabbit can be found in seven towns in Maine, two more than just six years ago, and the number of colonies has more than doubled to 46 known sites in that time, according to the state’s small mammal biologist.

The native New England cottontail rabbit, which is on the Endangered Species list, is found in southern Maine, but its non-native invasive species cousin the Eastern cottontail is rapidly gaining ground, said Cory Stearns, small mammal biologist.

The two species eat similar foods, the main difference being where they live. Easterns will live closer to people under decks or porches or other human structures and are less timid about open space. That allows them to proliferate in areas where the native species won’t because they prefer to hide in bushes and thickets.

The concern is that the Easterns will dominate, making it harder for the New Englands to rebound, Stearns said. Because of that and the state’s ongoing research and monitoring program, biologists are asking Maine residents to report any sightings of the two species of rabbits.

It’s difficult to tell them apart, but often the Eastern cottontail will have a white spot on its forehead. It also has bigger eyes that give them more side vision, he said.

It’s much easier to tell them apart from snowshoe hares in the winter. Snowshoes turn white, allowing them to hide in plain sight on the snow, while rabbits are brown year-round, Stearns said.

The New England cottontail saw its highest numbers in the 1960s when there were a lot of abandoned farms that provided thickets for hiding places. As the forest grew up and matured around those areas, the bushes and hidey-holes disappeared.

It now can be found in Cape Elizabeth, York, Wells, Scarborough, Kittery, Eliot and Kennebunk.

The low point was in 2018, when there were only 21 sites populated by the New England rabbits. The Easterns were first spotted in Maine in 2017 in Portland, Old Orchard Beach, the Berwicks and Wells.

The scientists collect rabbit feces, called pellets, for genetic testing to determine which species is inhabiting a space. They also can figure out how many individuals are in a colony.

If you want to help out by reporting a rabbit sighting, fill in this form on the Maine Department of Inland Fisheries and Wildlife website.