Wisconsin's opossums are a misplaced oddity

The opossum is a very unique animal that can occasionally be observed in both rural and urban settings. It is the only marsupial in Wisconsin.

Marsupials are animals that give birth to their young which are very small. These small, finger-sized babies will then crawl up into a pouch on their mom's underside and spend the next several months there being nursed and protected by her. Kangaroos from Australia are another example of a marsupial.

The opossum is a rather simple animal that moves about slowly looking for food. It has the most teeth of any mammal in Wisconsin (50) and will eat just about anything. At times, when threatened with danger, they will exhibit a phenomenon known as "playing possum."

While it looks like the animal is "playing dead," it has in reality "passed out" due to the constriction of the blood vessels that supply blood to the brain. Release of compounds from the adrenal glands due to the threat causes this condition.

Once the threat has passed, the blood flow returns and the opossum will revive and continue on its way. It is also a frequent casualty on our road ways as it has little fear of motor vehicles and will always come in second in these encounters.

In this area, the opossum is a rather new resident. When I was a youth, their range extended as far north as southern Wisconsin. Within the last 30 years possums have moved from their southern range and are now quite common.

They really don't belong this far north, however. If one would examine an older opossum closely, one will note the frost-bit ear tips and shortened tail tip frozen off by our harsh winters. It may only take a few very cold winters in a row to send the newcomers packing to a warmer part of the state.

According to Jim Evrard, DNR research biologist, as published in "Duck Production and Harvest in St. Croix and Polk Counties Wisconsin" (2002), "As a result of a recent range expansion from the south, the Virginia opossum (Didelphis virginianus) appeared late in the study and was first reported in a road kill in 1990."

Keep a sharp eye out for the opossum and you might be lucky enough to see one out and about looking for a bit of food. Their small even-spaced tracks in the sand or snow with the tail drag down between the paw prints point out the presence of this interesting creature.

Green Fire

A special showing of "Green Fire" will be held at the New Richmond's Old Gem Theater on Thursday, Sept. 27, from 7-9 pm. This film is the first ever made about legendary environmentalist Aldo Leopold.

"Green Fire" highlights Leopold's extraordinary career, tracing how he shaped and influenced the modern environmental movement, inspiring projects all over the country that connect people and the land. It is a film suitable for the entire family. A short narrative will be given prior to the showing with special guests invited. This special showing is sponsored by the Friends of the St. Croix Wetland Management District and is free and open to the public.

Buckthorn

On Saturday, Oct. 6, starting at 9 a.m. at the New Richmond Nature Center, located west of New Richmond on County Highway A (old highway 64), Jack Rasmussen, local conservationist, will provide a buckthorn and invasive species eradication demonstration.

Jack will provide insight into the identification of various invasive species including buckthorn and honeysuckle demonstrating and describing effective ways to control them. Jack will also answer any questions concerning a variety of aquatic invasive species you may have.

The St. Croix County Alliance has funded a program of herbicide distribution for anyone interested, with Jack administering the program. For more information, contact Mike Reiter at 715-294-3950 or email at mikereiter@centurylink.net.

Railway

Fifteen years ago, the New Richmond Preservation Society and the Osceola and St. Croix Valley Railway sponsored a steam engine train ride from Mary Park in New Richmond, through the countryside, across the St. Croix River over the High Bridge into Minnesota and back. My wife Sally, daughter Jenny and I took the two-hour ride on the train that day and had a great trip back in time as the countryside took on a whole new perspective. It was a memorable experience.

Last weekend we were fortunate to have two of our grandkids join us on another train excursion. The City of Osceola was holding their "Wheels and Wings" celebration and the Osceola & St. Croix Valley Railway, each Saturday and Sunday, May through October, provide vintage turn-of-the-century railcar rides from Osceola to Marine-on-the-St. Croix. Three-year-old Zach and 7-year-old Sophia had a great time as they experienced their first train ride. The 90-minute trip flew by and the kids couldn't stop talking about that wonderful experience.

If you want a bit of something out of the ordinary, check out the railway trips on the Osceola and St. Croix Valley Railway website. You won't be disappointed.

Fall Management on the WPA

By Tom Kerr

USF&WS

As the fall colors start to appear and leaves begin to drop, the St. Croix Wetland Management District is starting some of our fall management activities.

Probably the most noticeable project you will see when you spend time on local Waterfowl Production Areas is the mowing of firebreaks around controlled burn units. In an effort to re-invigorate the grasslands and control brush and trees, we will be burning about 1,000 acres on WPAs in Polk, St. Croix and Dunn counties. Most of this will happen next spring but some units may be burned this fall.

The burn schedule and total acres managed each year is directly tied to weather conditions. Each management unit has a very specific window of conditions (wind direction, wind speed, relative humidity, etc.) that must be met before we can start the controlled burn.

Our local grasslands, including native prairie and cool season fields dominated by brome, need some form of disturbance to prevent the invasion of trees. Historically, this area of St. Croix County was dominated by prairie, wetlands and oak savanna which were maintained or "disturbed" by wildfires or grazing. Our management efforts are an attempt to mimic these natural processes. Haying and grazing are other management tools that provide "disturbance" and help maintain grassland.

Over the next few years, you will start to see other management tools like haying and grazing used on local WPAs. Although these management activities may temporarily displace wildlife, many of these grassland and savanna dependent species such as mallards, meadowlarks, bobolinks, northern harriers and many others evolved with disturbance.

If you would like to stay informed about the controlled burns on area WPAs, check us out on Facebook by searching for St. Croix Wetland Management District. For more information on the St. Croix Wetland Management District, check out our website at http://www.fws.gov/refuge/st_croix_wmd/.