February 2004





There seems to be a lot of discussion and media coverage regarding the announcement of impaired waters in Minnesota. What are impaired waters and what is prompting the heightened concern?

Maple sap runs best when daytime temperatures are in the high 30s to mid-40s and overnight temperatures are below freezing. This cycle of above-freezing days and below-freezing nights needs to continue for several days, although nature has been known to occasionally provide a good run under less perfect conditions. Some sap may flow as early as late January or as late as May, but the typical time for a ?good? sap run in Minnesota is March 15 to April 20. Sap is converted to syrup by boiling off most of the water content of the sap, which leaves the sugar and flavor behind. It usually takes 30-40 gallons of sap from a sugar maple to produce one gallon of pure maple syrup.

Dave Crawford, Wild River State Park naturalist


Our snowfall totals this winter have made cross country skiing ideal for the first time in years. What sort of skiing opportunities are available throughout Minnesota?

The DNR supports 156 cross country ski trails statewide, totaling more than 1,600 miles. These trails are a great way for people to see the unique natural environments of Minnesota - from the prairies to the northern hardwood forests. Just like anglers, skiers are required to purchase and possess a license - daily, seasonal or three-year ski pass - before venturing into the wilderness. Most state parks and some trailheads do sell daily passes, but not all of them do, so it is recommended that skiers pick up their passes at any of the more than 1,800 DNR electronic licensing agents statewide or on the DNR's Web site. The DNR Web site has a list of every ski pass trail in the state; log onto MN DNR Cross-country Skiing to find out more.
Paul Nordell, projects coordinator, DNR Division of Trails & Waterways


Winter is tough on everyone, but can be especially difficult for wildlife. How does the cold and snow affect deer, and how do they survive Minnesota's winter weather?

Deer begin preparing for winter by shedding their summer coat and replacing it with a heavier winter coat. During a cold snap, they can make the hairs of their fur coat stand erect, which traps air near the skin and increases the insulation value of their winter coat. This is similar to birds fluffing their feathers. Deer store most of their fat reserves during the summer months because the twigs they eat in the winter lack the nutritional value of green vegetation. They tend to migrate to areas with conifer trees such as white cedar, balsam, fir, white spruce or jack pine. Conifers are warmer than trees that shed their leaves because they absorb energy from the sun. And, like most of us, deer also try to limit the amount of time spent out in the elements. As far as how our current winter will affect Minnesota's deer population, it's too early to tell. That impact depends on snow depth coupled with how long the snow stays on the ground.
Frank Swendsen, DNR Wildlife Supervisor


Some homeowners have found a bat, or a number of bats, while remodeling rooms or making other home improvements this winter. What should they do with the little winged creatures?

If the bat is awake and flying when first noticed, close the doors to confine the bat in one room. Then open the doors and windows to the outside and allow the bat to fly out of the building. If this does not work, capture the bat in a towel (wear gloves to protect your hands), or use a container such as a small trash can or bowl to place over the bat when it lands. Take the container outside and shake the bat out onto a tree branch or surface from which it can fly away. Do not drop it onto the ground or into the snow, because it will have difficulty flying from such a cold, low spot. If the weather is severely cold, release the bat in a sheltered area.
Joan Galli, DNR nongame wildlife specialist


DNR Question of the Week Archive