Swamp otters

        It’s mud season in Central New York, and along the edge of a pond created by a massive beaver dam, patches of melting snow are interspersed with ankle-deep mud and seeps of water streaming down from a hemlock-covered hillside. Recently arrived red-winged blackbirds continuously call as Scott Smith slogs along the trail looking for any indication that river otters are in residence.
        “Raccoons are the bane of my existence when looking for otter sign,” says the wildlife biologist for the New York Department of Environmental Conservation, noting the similarity in their tracks after the mud and snow have thawed and refrozen multiple times. But raccoon tracks aren’t the only mammal sign he finds. Beaver are clearly quite active around the impoundment, as are mink, muskrat, deer, fox and coyote.
        At an opening beneath an alder thicket, Smith finds what he’s looking for. What looks to the uninitiated like a two-day-old pile of vomit is in fact what Smith calls an otter toilet – piles of fish

River otter eating a fish (Mary Holland)

scales mixed with fecal matter, all clearly smelling like fish. Its location next to open water and beneath shrubs make it what Smith says is a typical toilet site.
        “I’ve seen enough of them that this situation usually means a toilet,” he says. “I’ll look at 47 of these and not find anything, and then there it is. It’s a pull-out area to rest, eat, toilet. Often I’ll find a half-eaten fish in there.”
        During the next half hour, Smith finds additional otter toilet sites at similar locations around the pond, as well as on top of fallen logs and on several beaver lodges and muskrat dens. “There’s an advantage for otters living around beavers because it provides them with habitat, den sites, and resting sites,” he says. “I’m not sure there’s an advantage to the beavers, other than that otters are alert for predators and chirp a lot.”
        Smith’s hunt for signs of river otter activity is part of a region-wide survey to learn how well the animals have re-established themselves in central and western New York after reintroduction efforts in the early 1990s. Otters were extirpated from much of the region in the 1800s and early 1900s due to unregulated trapping, the clearcutting of forests for farming, and the growth of industrial activity that degraded water quality. In the years since, forests in the region have rebounded and water quality has improved.
        Although transient otters from nearby Pennsylvania – or perhaps from the Adirondacks or Catskills regions – would occasionally find their way to the area, Smith says it would have taken a century for the animals to re-colonize the area on their own. To speed up the process, a group of private citizens worked with the state legislature to establish the New York River Otter Project and fund the reintroduction of otters. Nearly 280 river otters were captured in the Adirondacks and Catskills and relocated to 15 sites in central and western New York over a three-year period in the 1990s. Twenty-five years later, Smith and his colleagues conducted two years of monitoring surveys at 1,200 sites across the state to assess how well the population was doing.
        “River otter are not easy to count because of the habitat they’re in and their elusive nature,” he says. “With fisher, you can throw a hunk of meat on a tree trunk and put a camera trap up and document them easy. We can’t do that with otter. And you can’t see them with aerial surveys.”
        It took several years of trial and error to find an adequate survey method, but once they did, they found that otters had successfully re-colonized most of the available habitat in the survey area.
        “We realized that river otters are misnamed,” says Jacqueline Frair, a professor at the SUNY

Scott Smith searches for signs of otters (Todd McLeish)

College of Environmental Science and Forestry in Syracuse, who led the survey project. “They should be called the swamp otter. They like marshes and swampy backwaters more so than big rivers and big lakes. When they were released at the edge of big lakes, they moved to find a better place.”
        Smith agrees, though he adds that forests are critical otter habitat, too. “Forests help filter out contaminants before they get into the wetlands. And otters travel a lot through forests. They go up one watershed, take off cross country over hill and dale and drop into the next watershed.”
        According to Frair, the river otter survey was launched to collect data so a statewide wildlife management plan could be prepared for the species. Because trapping of otters is prohibited in the area where the animals were relocated, harvest data was unavailable to compare with other parts of the state.
        “We wanted to figure out whether they’ve recovered, and if so, what should our management goals be for them,” she says. “The state is responsible for opportunities to use these resources wisely, so one underlining question is whether they’ve gotten to the point where there are opportunities for trapping, or at least, can we release some of the restrictions we’ve put on beaver trapping in the area because otter can handle incidental losses.” (Beaver trappers occasionally capture otters by mistake.)
        The otter recovery took longer than most people would have guessed. Some thought the animals would be highly visible everywhere they looked by now, but otters typically avoid areas where human populations and road density are high, Still, the scientists believe otters have reached the carrying capacity of their habitat across much of the region.

        River otters are larger than most people imagine, growing to 4 feet long (including their tail) and weighing more than 25 pounds. Despite their name, they spend only about half their time in the water but are seldom far from it. They feed primarily on fish, frogs and crayfish, though they’ll consume almost any marine invertebrate, and they den in banks along rivers, especially sites with entrances below water. Females give birth to three or four pups every year in late April or early May, and the pups are independent within six months, though some will remain with their mother through the winter and disperse the following spring.
        They are tenacious animals that can defend themselves against most aggressors. “Coyotes could pick off a few, bobcats maybe too, but the young are the most susceptible,” Smith says. “Once an otter becomes an adult, they’re pretty resistant to most predation. The bigger threat is roadkill. They don’t seem to have the gift to look both ways before crossing the road.”
        Despite facing similar issues as the otters in central and western New York, river otters in most of the rest of the Northeast never disappeared entirely – though their numbers were depressed in many places in the late 1800s and early 1900s. Now they are somewhat common just about everywhere. In the Adirondack region of New York, the ample protected habitat and limited timber harvesting kept river otter numbers high even during the population declines in other parts of the region. The rugged terrain reduced opportunities for farming and development, so water quality has remained high for otters that are known to have a low tolerance for polluted water.
        “The big difference between the Adirondacks and the rest of the state is that we’ve just got so much habitat,” says Tim Watson, the state biologist who monitors river otters in much of the Adirondacks. “We’ve got lakes and rivers and beaver ponds spread out all through our 6 million acres, so we have a lot of habitat that can support higher densities of otters. And we’ve got a lot of areas that are inaccessible to trappers.”
        The situation in northern New England is similar, with the state biologists there declaring their otter populations abundant thanks to plentiful undeveloped river systems, lakes and tributaries. Along the Maine coast, river otters have even been observed preying on rare seabirds on coastal islands in recent years, proving that the animals occasionally spend time in salt water.
        “River otters are a fascinating species,” says Patrick Tate, a wildlife biologist for the New Hampshire Fish and Game Department. “They seem to thrive in dark tannic water where they hunt bottoms and edges using their whisker sets located on their chin and nose area. While some otter are taking advantage of our dark-watered – though clean – beaver flowages, others have occupied New Hampshire’s largest lakes and river systems.”
        Southern New England experienced considerable deforestation for farming, as well as industrialization, in the 1800s that affected water quality, and while otter numbers declined precipitously a century ago, they aren’t believed to have ever been extirpated. Today they can be commonly found in most available habitat. As elsewhere, they have benefitted greatly from the presence of beavers and beaver ponds and whatever other waterways support their preferred prey.
        Every state in the region except Rhode Island uses trapping as a way of managing and monitoring river otter populations. Harvest numbers are relatively low in most areas, ensuring that the harvest is sustainable. Massachusetts reported just 35 animals trapped in all of 2019, and the average otter harvest in Maine over the last 10 years has been approximately 600 animals. Because fur prices vary considerably from year to year, which causes great fluctuations in trapper effort, biologists in Maine are seeking new tools for assessing otter numbers and managing the population of furbearing animals, including camera traps, environmental DNA surveys and citizen science projects.
        The trapping situation in Rhode Island is unique. Trapping of river otters in the state has been prohibited since 1970, when a state legislator apparently observed the illegal shooting of an otter and subsequently succeeded in passing legislation to ban otter trapping. Despite several efforts to overturn the ban through the years, it remains in place, making Rhode Island the only state east of the Mississippi to prohibit river otter trapping, according to state biologist Charles Brown.
        Whether trapping will be permitted in the coming years in central and western New York, where the animals were reintroduced in the 1990s, will depend on the outcome of the management plan being prepared by the state.
        “They’re very cautious about saying ‘otter are recovered, so let’s hunt them,’” Frair says. “But collectively we’re comfortable with the comparisons we’ve made about where they’ve recovered and where they’ve had sustainable harvests. We know populations can sustain harvest, but we’re not going to immediately open the area to harvest. They’ll probably monitor them again first. We want to see how sensitive our methods are to being able to detect changes in the population.”

        Back at the beaver pond in central New York, Scott Smith stands atop the sturdy beaver dam and gazes across the water at an abandoned beaver lodge, which he believes is where the family of otters is living. Judging by the number of otter toilet sites he found during his survey, he guesses that a family unit of otters – a female with kits – is spending the winter there.
        “They’ve probably been hunting here all winter,” he says. “Fewer toilets would mean that this is probably just a travel link between other habitats. But I think we’ve got a family here. The fish scales we’re seeing are small, so they’re probably eating minnows, but larger scales might indicate they’re eating bass or carp or sunfish. You can tell their main prey base by looking at the scales in their scat.”
        Smith drives a quarter mile north to more stream-like habitat leading into the beaver impoundment, where he finds several muskrat dens, each topped with otter scat.
        “We definitely have a good conservation success story to tell here,” he says.

This article first appeared in the Winter 2020 issue of Northern Woodlands magazine.