June 2007

The DNR communications team works with agency experts to develop the weekly questions and provide the answers. This feature addresses current DNR issues, interesting topics, or the most frequently asked questions from around Minnesota.






Earthworms make great fishing bait, but recent research has discovered that they are a threat to Minnesota's forests - making them an invasive species. What sort of damage do they cause?

It really is true that all of the terrestrial earthworms in Minnesota - including night crawlers - are non-native, invasive species from Europe and Asia. Invading earthworms eat the leaves that create the "duff" layer in forests and are capable of eliminating it completely. This layer is important to native plants and ground dwelling animals. Studies conducted by the University of Minnesota and forest managers show that at least seven species are invading our hardwood forests and causing a loss of tree seedlings, wildflowers and ferns. In areas heavily infested by earthworms, soil erosion and leaching of nutrients may reduce the productivity of forests and ultimately degrade fish habitat. However, many areas of the state are still free from earthworm disturbance. Because earthworms are non-native, it is illegal to release them into the wild, according to Minnesota Statutes 84D.06, which means anglers should dispose of unwanted bait in the trash.

- Jay Rendall, DNR Invasive Species Program coordinator


How do I know if it is a minnow?

Not all small fishes are minnows; many are the young of other fish. A number of characteristics serve to separate small fish from true minnows. All minnows have naked heads except during breeding season when mature male develop many hornlike bumps, called tubercles. Some minnows also develop bright colors during breeding season, as suggested by such names as redside dace, redbelly dace, rosyface shiner, red shiner and redfin shiner.

A single dorsal fin with fewer than 10 soft rays is characteristic of all native minnows. In the introduced carps and goldfish, the dorsal fin has a hard ray and more than 10 soft rays. Minnows lack teeth in their jaws but have specialized teeth in their throat - pharynx - region. These pharyngeal teeth are useful in identifying the various minnow species.

- Roland Sigurdson, DNR MinnAqua Program


The Reinvest in Minnesota (RIM) program uses money raised from the sale of the critical habitat license plates to purchase and develop important areas for fish and wildlife. What sort of an impact has this program made in Minnesota?

The Reinvest in Minnesota Matching program was established in 1986 by a recommendation from the Citizen's Commission to Promote Hunting and Fishing in Minnesota. Since that time, the Minnesota Legislature has appropriated $27 million and the Critical Habitat Conservation License Plates have generated more than $19.5 million for acquisition and enhancement of critical habitat. These funds have matched private donations of land and cash totaling more than $45 million. The money has helped restore wetlands, improve forest habitat, plant critical winter cover, preserve habitat for rare, native plant and animal species and protect reproduction areas for fish. The program has also created public places for hunting, fishing, hiking, wildlife watching and other outdoor activities. With the help of Minnesotans and other conservation-minded people, the RIM Matching Program has been able to acquire and protect more than 76,000 acres of land.

- Kim Hennings, DNR RIM Program coordinator


Bird feeding and birdwatching have fast become two of the most popular recreational activities. Where should property owners put up bird feeders and how should they be arranged?

There are more than 30 different bird species that come to feeders to feast on a variety of foods ranging from sunflower seeds to suet and mealworms to sugar water. Birds attracted to a backyard feeder depend on both the types of food offered and feeder used. When arranging feeders, property owners should identify the locations from where they wish to watch birds, such as near a back porch or kitchen or bedroom window. However, it is especially important that feeders be kept at least 10 feet from conifers, brush piles or leafy shrubs to prevent ambush by cats or raptors; ground feeders should be protected by wire mesh fencing. In addition to proper placement, property owners should provide water throughout Minnesota's four seasons and keep feeder stations clean and sanitary to help minimize the potential threat and spread of diseases. Additional information about birds and bird feeding can be found in a DNR publication "Wild About Birds: The DNR Bird Feeding Guide." It is available for purchase through most major bookstores and Minnesota's Bookstore.

- Carrol Henderson, DNR Nongame Wildlife Program supervisor


DNR Question of the Week Archive