Category Archives: weasels

Indiana River Otters: From Recovery to Control

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otter_pair_maxwell“The [Indiana] Department of Natural Resources is considering allowing a trapping season for river otters less than two decades after being reintroduced to the Hoosier landscape,” wrote John Martino, outdoors columnist for the Kokomo Tribune last week. In the article, Martino says the river otters were official declared extirpated from Indiana in 1942.

The state’s reintroduction program began in 1995 and included 303 river otters trapped in Louisiana and released in Indiana, the article says. Ten years later river otters were taken off the state endangered species list.

In 2013 the IDNR received more than 64 formal complaints about river otters eating fish from private ponds, Martino reports. The department issued 11 nuisance animal control permits in 2012, he adds. Now, he reports, the department is considering controlling the river otter population by opening a trapping season for river otter in the counties where it is most abundant.

Read the article in the Kokomo Tribune here.
Information on river otter from the Indiana Department of Natural Resources is here. It includes links to several data sets, including a mortality study.

Photo: courtesy Indiana Department of Natural Resources

Western Wildlife Agencies Request Delay on Wolverine Listing

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WolverineSnowWestern states are “feeling that climate change models are not a reason to list species under the Endangered Species Act,” said Bill Bates, wildlife section chief for the Utah Division of Wildlife Resources (DWR) in an article in the Salt Lake City Tribune last week.

The US Fish and Wildlife Service (USFWS) has proposed listing the wolverine as threatened in the lower 48 states, where they are dependent on having snow on the ground between January and May, their denning season. Climate change puts that snow coverage at risk.

The Western Association of Fish and Wildlife Agencies has asked the USFWS to extend its comment period by three more months.

Read the Salt Lake City Tribune article here. It includes a nice map.
Read the Associated Press article in the Missoulian, here. It includes a photo of adorable wolverine cubs.

Photo: Wolverine. Photo Credit: Steve Kroschel

River Otters Exposed to Banned Chemicals

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otter teamRiver otters have made a remarkable comeback in the last few decades, particularly in Illinois, as we reported recently. However, those Illinois river otters have significant amounts of long-banned chemicals — such as PCBs and DDE (a chemical that results from the breakdown of DDT) — in their tissues, a recent study from the Illinois Natural History Survey has found.

A press release from the University of Illinois reveals that for one chemical, the concentrations were higher in the otters now than they were when the chemical was in legal use:

The researchers were surprised to find that average concentrations of one of the compounds they analyzed, dieldrin — an insecticide (and byproduct of the pesticide aldrin) that was used across the Midwest before it was banned in 1987 — exceeded those measured in eight river otters collected in Illinois from 1984 to 1989. Liver concentrations of PCBs and DDE (the latter a breakdown product of the banned pesticide DDT) were similar to those in the earlier study, the release says.

Scientifically, this is a mystery still to be solved. Were the chemicals used long after they were banned? Did it take decades for the chemicals to climb the food chain from algae to top predator? Are female otters passing the contaminants to their offspring in their milk?

But for wildlife managers, it has a lesson useful right now. When trying to find causes for unknown population declines, don’t dismiss the effects of toxic chemicals just because those toxic chemicals were banned from use decades ago.

The University of Illinois press release.
The paper, in the journal Ecotoxicology and Environmental Safety. It is a free access journal.

Photo: Samantha Carpenter (left), a wildlife technical assistant with the Illinois Natural History Survey (INHS); Kuldeep Singh, pathobiology professor at the U. of I. Veterinary Diagnostic Laboratory; Nohra Mateus-Pinilla, an INHS wildlife veterinary epidemiologist; and U. of I. animal sciences professor Jan Novakofski found that Illinois river otters are contaminated with banned pesticides and PCBs.  Credit: L. Brian Stauffer

River Otter Comeback in Illinois

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River_OttersIllinois Department of Natural Resources furbearer biologist Bob Bluet told the Springfield (IL) State Journal Register that the state’s first river otter trapping season culled slightly more otters than anticipated because fur prices were up. “More people were trapping and there was more opportunity to catch otters,” he said.

River otters haven’t been trapped in Illinois since 1929. It was believed their numbers were down to just 100 before 1990. A reintroduction program, which ran from 1994 to 1997 was so successful, that the otters became s nuisance in some places, the article says. The recent trapping season harvested 13 percent of the state’s population, not quite enough to reduce the number of otters in the long term, Bluet told the newspaper.

For more details on the river otter’s restoration in Illinois, the nuisance factor and the recent trapping season, read the article in the Springfield State Journal Register.

An abridged version of the article ran in the West Kentucky Star.

Photo: River otters by Jim Leopold, courtesy US Fish and Wildlife Service

 

 

Fishers Not Found in Wyoming

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FisherHabitat models say that there should be fishers in the Wyoming section of the Northern Rocky Mountains, says the Billings Gazette, but a search by the Wyoming Game and Fish Department of the Sunlight Basin, near the Beartooth Mountains, just to the east of Yellowstone National Park did not turn up any fishers.

“We didn’t find any (fishers),” the Billings Gazette article quotes Game and Fish nongame biologist Bob Oakleaf as saying. “What we did find is (pine) marten everywhere.”

It has been about 10 years since the last fisher sighting in the state, the article notes. The Northern Rockies population of fishers had been rejected for listing under the federal Endangered Species Act. Further searches for the fisher will be conducted next year.

More details about the search, and the history of fishers in Wyoming, are available in the article. Read it on the Billings Gazette website, here.

Photo: Fisher taking bait in Pacific Northwest. Courtesy US Fish and Wildlife Service.

 

 

River Otters Have Cat Disease

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euro_otter_by_Catherine_TriggYou may remember toxoplasmosis being the key factor in the deaths of sea otters a few years ago. (If not, find a refresher here.) But what about river otters?

A recent paper in the journal Parasites and Vectors found that 40 percent of the river otter carcases tested in England and Wales were positive for toxoplasmosis. None of the river otters in the study had died of the infection. (The concern, of course, is any sub-lethal effects.)

You can find the full text of the paper in Parasites and Vectors, here.
You can read the press release from the American Bird Conservancy, here.

A similar study on US river otters, specifically North Carolina river otters, was published in 1997. There, 46 percent of the tests were positive. Read the abstract, here.

Ten years later, another study, this one in the Journal of Wildlife Diseases, found that river otters who feed in the ocean are more likely to be infected with various human pathogens, including the one that causes toxoplasmosis, if they lived closer to urban areas. You can read the abstract, here.

Photo: Eurasian otter by Catherine Trigg, used courtesy of the American Bird Conservancy

Got Mink?

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mink-at-denThe Florida Fish and Wildlife Conservation Commission (FWC) would like to learn more about Florida’s three subspecies of mink, and it is reaching out to the public for help.

“We know that mink are more likely to be found in and near salt-marsh habitat on both coasts of Florida but the reports people provide will help us pinpoint where we do research,” said Chris Winchester, wildlife biologist with the FWC’s Fish and Wildlife Research Institute in a press release issued by the commission this week.

For reasons unknown, mink appear to be absent from the freshwater streams, rivers and wetlands of central and northern Florida, the commission website says.

The effort includes an on-line mink sighting registry that includes a mapping tool. A similar Google Maps tool was used in a FWC public outreach effort to locate fox squirrels. That effort was quite successful. We covered it back in October 2011.

Read the FWC press release here.
Read the additional information on the study here.
Find the mink sighting registry with Google Maps tool, here.

Photo: Mink looking out of den. Photo credit: Patrick Leary, courtesy Florida Fish and Wildlife Conservation Commission.