River otters return and thrive in Ohio waterways

It was June 13, 2017. Curt Wagner and a coworker were canoeing in the Mahoning River, scouting for places to put in the equipment they would need to do their fish surveys.

As they reached a clump of trees not too far from Leavittsburg, they were suddenly surrounded by four or five river otter pups. While mom supervised from 15 or 20 yards away, the pups darted around the canoe, popping up to inspect the strange, metallic vessel and its surprised inhabitants.

“They were swimming all around, poking their heads up beside the canoe,” said Wagner, fisheries management supervisor for the Division of Wildlife District 3 office in Akron. “One would go down and another would pop up,” he recalled, laughing. “It was almost like they were messing with us.”

Absent from Ohio

Such an encounter would not have happened just 40 years earlier; like many other species, river otters had been absent from Ohio for most of the past century. But Dennis Solon, manager of the Killbuck Marsh Wildlife Area, was one of the lovers of wildlife employed by the state who helped bring river otters back in the late 1980s and early 1990s.

The wildlife area, which covers more than 5,500 acres in Wayne and Holmes counties, was chosen for the first otter reintroductions because of the good water quality in Killbuck Creek. There had been studies showing that poor water quality affects otters’ reproduction, Solon said.

The first group of otters came from Arkansas. Sadly, the rush to trap, box and transport the otters proved too stressful, and most did not survive.

Successful transport

Division of Wildlife officials heard of a gentleman in Louisiana who trained trappers on how to get the feisty animals into a box safely — for both the otters and the humans. The man then kept the otters for six weeks, getting them to a vet for vaccinations and monitoring their health before sending them to Ohio on a plane.

Once here, the otters were implanted with transmitters by Dr. Lawrence Smith of Shreve, who was honored by the Division of Wildlife for his efforts. Those devices, about the size of a C battery, showed that the second group of otters released around Killbuck Creek not only survived but were thriving.

Later, more otters were released in the Grand River, Stillwater Creek and the Little Muskingum River. Division of Wildlife records show that a total of 123 otters were released in those four watersheds between 1986 and 1993.

Intensive study

After a few more years, wildlife officials wanted to see how the reintroduced otters were faring and began a two-year, intensive study. A wildlife technician at the time, Solon was one of those who traveled to different watersheds and trapped otters, using modern foothold traps that didn’t hurt the animals. But then came the tricky part.

“It was quite a circus getting them out of the trap and into a box to go to the vet,” Solon said. “They’re a handful, and they’re not afraid to bite if they feel threatened.”

Still, Solon and others persevered “because we were doing a groundbreaking thing. That’s why we got into this field, we love wildlife,” he said.

The 56 otters they captured for the study were also taken to Dr. Smith to be implanted with transmitters; Solon and others followed them for two years until the batteries ran out. The study showed that otters had spread from the original four streams in eastern Ohio to 52 watersheds in other parts of the state, Solon said.

Male otters, especially, are prone to travel long distances and are pretty speedy, not only in the water but on land, he said. One male’s transmitter showed he had gone from Killbuck Creek to Black Creek in Medina County, a distance of more than 40 miles, in just two days.

Today, otters have been documented in all but four of Ohio’s 88 counties, which Solon calls “a tremendous success story.” River otters had become so successful, in fact, that wildlife officials were starting to get complaints from fish farmers and pond owners.

Bridge surveys

Otters were removed from the endangered species list in 2002, and the first trapping season began in 2005. Last year, bridge surveys were conducted at 421 sites in Ohio, and signs of otters were found in almost 25 percent of them.

Laurie Brown, a wildlife research technician for the Division of Wildlife, has been doing those surveys for the past 10 years in District 3, which covers Northeast Ohio.

The bridge surveys were started in 2000 and are typically done in January through mid-February. Division of Wildlife staff visit each site just once a year. They try to time their visit to each bridge so it’s about four days after a rain or snow, hoping the otters have had enough time to make tracks.

Surveyors walk 300 meters upstream, then 300 meters downstream, recording what they see. In addition to tracks, they also look for poop, leftovers from prey, or latrines. Believe it or not, otters will go in the same place multiple times, perhaps to mark territory, or to advertise their availability for mating.

Though she has yet to see an actual otter, Brown has seen tracks, as well as some of the other signs, around Little Chippewa Creek and some of the small waterways she has surveyed in Wayne County.

“I feel like they’re just passing through, looking for food or maybe potential mates,” Brown said, adding that she thinks otters prefer larger streams if they’re going to take up permanent residence.

Tracking travelers

Wildlife staff have been encouraged to find otters that have taken up permanent residence in places far away from the original release sites, like the Maumee River in Northwest Ohio and the Ohio River near Cincinnati in the southwest.

They wonder if these “pockets” are Ohio otters that have moved into those parts of the state, or do they include migrants from other states as well?

“Either way, it’s a positive thing for the re-establishment of the population and making it more genetically diverse,” said Katie Dennison, wildlife biologist with the Division of Wildlife, whose main responsibility is monitoring, research and management of Ohio’s 16 furbearer species.

While overharvest was the major cause of the otters’ disappearance from Ohio, human impact on the state’s waterways and declining water quality both played a huge role. Sometimes dams and logjams helped, but steep banks, cliffs, overhangs and other changes did not bode well for otters or their prey.

Like bobcats and other species, river otters are opportunists that will eat small mammals, birds, amphibians and reptiles when available. But fish make up the majority of the otter’s diet, especially carp, suckers, sunfish and catfish, Dennison said.

Unlike otters on the East and West coasts, river otters in Ohio are not very social, she said. Their family groups usually just include the mom and pups, though sometimes a non-breeding female will join them.

Delayed implantation

Female otters can breed every year, Dennison said, but they have delayed implantation. That means their eggs are fertilized, but may not implant for eight or 10 months. After that is a two-month gestation period before the pups are born.

So otters may mate in March and April, but a lot of pups are born then, too. Females often give birth, then breed again shortly afterward. They’re not sure, but scientists think the advantage of delayed implantation is timing it so that resources are available to sustain the pregnancy, Dennison said.

Return of wildlife

Solon doesn’t know the answer either, but is thrilled that otters are living and reproducing around Killbuck Creek, where he helped reintroduce the species more than 30 years ago.

Growing up in Loudonville, he doesn’t recall ever seeing turkeys, geese or other kinds of wildlife — except for a pair of deer that lived inside a fence around the Mansfield pumping station.

Since he began working for the Division of Wildlife in 1980, Solon has not only seen the return of deer and other species that had disappeared from Ohio, but the proliferation of many that he never thought he’d see.

Now, sandhill cranes and bald eagles nest and raise their young in the Killbuck Valley, which is also a hub of barn owl activity, he said. Solon doesn’t even seem to mind that in the 2019-2020 season, 256 otters were harvested in 38 counties of Ohio, the highest modern-day harvest on record.

To him, that’s just more evidence of their success story, thanks to the efforts of the Division of Wildlife.

“With management, we’re producing a crop each year,” he said. “Some are harvested, the rest go on their way.” “We’re like farmers of wildlife.”