Muskrat population decline being studied

Muskrats are an important furbearer living in the thousands of acres of our area marshes and miles of ditches and streams. Local trappers have caught millions of these animals, used both for their skins and meat for hundreds of years.Before the Truth in Labeling Law was enacted, fashionable garments of muskrat fur were sometimes sold as the more glamourous-sounding Hudson Seal. Their soft, water repellent coats are durable, with the outer guard hairs usually plucked and the underfur sometimes dyed.During the War of 1812, when livestock and game were scarce, people could go into local marshes and by smashing through muskrat huts, collect some of these abundant rodents for meat.Oral tradition supports a story that Catholics south of Detroit were given dispensation from the church — perhaps by the Pope himself, to eat the aquatic muskrats on meatless Fridays during Lent.There are still many local wild game dinners or muskrat feeds that feature this mild, finely textured, tender, dark meat sometimes called marsh rabbit that some compare to duck. They also remain popular around the mid-Atlantic coast where they have an even longer muskrat trapping tradition.They are baked, braised, broiled, roasted, stewed, cooked in creamed corn and made into creamy casseroles. Although I survived the simple preparation of using Shake and Bake chicken coating mix (BBQ Flavor) during my college days, Cooks.com lists 10 recipes for muskrat.The last time I had some 'rats, they were simmered in a giant roasting pan in a tomato sauce base until the meat fell off the bone.For over 25 years, trappers throughout the Midwest and Northeastern United States and Canada have documented a 10-fold decline in the formerly abundant muskrat populations. Locally, the most robust populations thrive in newly constructed wetlands.The harvest numbers from surrounding states and Ontario also support their observations. Ontario muskrat harvest went from 540,106 in 1986 to 53,553 in 2004, Pennsylvania declined from 720,000 in 1983 to 58,295 in 2010 and West Virginia shrunk from 34,643 in 1987 to 2,523 in 2004.While the causes remain unknown, some Ohio trappers have speculated that one or more of the following reasons may be to blame: natural population cycles, farm chemicals, rapid ditch and stream water elevation rises because of tighter field tile spacing, higher raptor and mink populations, pharmaceutical contamination, declines of cattail and other aquatic plant distribution and disease.Susie Prange, Furbearer Biologist for the Ohio Department of Natural Resources, Division of Wildlife summarized some of her research results in a recent issue of The Buckeye Trapper, the publication of the Ohio State Trappers Association.For her study, 592 donated muskrat carcasses from across the state were examined for age, sex ratios, female reproductive output, organ health and exposure to contaminants.Her observations indicated that females gave birth to an average of 15 young per year, resulting in 11 percent adults tallied in her sample. A few had liver lesions, consistent with tapeworm larvae.Pesticides and personal care products were detected in minor amounts, but heavy metals were much more significant. She found that 40 of the 41 animals tested for metals had moderate to severe levels of metal contamination and exposure above threshold levels for 1-to-18 elements.Most muskrats across Ohio suffer from exposure to six widely-used metals including antimony, calcium, iron, mercury, molybdenum and strontium and three muskrats had exposure to 17 or 18 different metals. She writes, "Such metal contamination can have negative effects on health, survival and reproduction."According to Prange in a follow up interview, future research will compare control animals from areas that tested clean to the ones from the most contaminated sampling locations, undertake histological observation of livers and kidneys to look for deformities and target additional pesticide and herbicide contaminants.Because of their widespread distribution and ease of capture where present, muskrats are the furbearer that most often provides the foundation for initial trapping exposure for new participants and kept experienced trappers busy in the fur shed prior to their population crash.Locally, some of our marshes would no longer exist had it not been for the value that muskrats provided.They appear to be serving as another canary in the coal mine that are telling us that something is wrong in our streams across a large portion of the North American continent.Muskrat trapping season remains open through March 15 in Erie, Ottawa, Sandusky and Lucas County, east of the Maumee River and through February 28 elsewhere.