OAK HARBOR, OH -- Wildlife surveys show river otters continue to make a strong comeback in Ohio, according to the Ohio Department of Natural Resources (ODNR) Division of Wildlife. Last year, otters were reported in 48 different watersheds encompassing 46 Ohio counties.
"It's really incredible," said Chris Dwyer, a wildlife biologist at the Crane Creek Wildlife Research Station in Oak Harbor. "We continue to see otters showing up in parts of the state and in numbers that we didn't expect to see for quite some time."
Wildlife biologists report that river otters have been reproducing and expanding their range across the state since 123 otters were released in four eastern Ohio watersheds between 1986 and 1993.
Otters, native to Ohio, disappeared in the mid-1800s from loss of high-quality habitat and unregulated trapping. ODNR wildlife biologists currently estimate the number of otters in Ohio to be around 1,700 and growing. Due to their increased numbers, otters are a candidate for de-listing from the state endangered species list.
During the reintroduction program, 123 otters were released in the watersheds of the Grand River in Trumbull County, Killbuck Creek in Wayne County, Little Muskingum River in Monroe County, and Stillwater Creek in Harrison County. Most were obtained from the Louisiana bayou region using modern foothold traps. Since then, observations have continued to increase not only in northeast Ohio release sites, but in western and southern Ohio counties, 100 miles or more from the nearest release site.
Observations also include sightings of otter families, indicating successful reproduction. Surveys indicate otters are also travelling in from other states. Two road-killed otters found in Ohio were originally released in Kentucky and West Virginia.
Wildlife biologists monitor otter populations using several methods, including an annual snow track survey by helicopter. Biologists also examine carcasses of otters accidentally killed on roadways to gather important information on age, sex ratios and signs of reproduction. Bridge surveys are also conducted throughout eastern Ohio in December and January to examine the degree in which otters are occupying watersheds.
Otter observations are recorded and used to build a database to help understand the growth and range of otters in Ohio. Most of the information on the expanding otter population comes from Ohio residents who report otter observations. People who see river otters are encouraged to contact a wildlife district office, or call 1-800-WILDLIFE.
Adult otters grow to about 3 feet long and can weight up to 35 pounds. They are highly adapted for swimming and travel long distances across watersheds. They prefer tributaries of major, unpolluted watersheds where there is minimal human disturbance.