6.4. SR 05-20-2002 - Laserfiche WebLink

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LIFE HISTORY INFORMATION DESCRIPTION: The Blanding's turtle is a medium to large turtle with a black or dark blue, dome-shaped shell with muted yellow spots and bars. The bottom of the shell is hinged across the front third enabling the turtle to pull the front edge of the lower shell firmly against the top shell to provide add~onal protection when threatened. The head and appendages are dark brown or blue-gray with sn~all dots of light brown or yellow. A distinctive field mark is the bright yellow chin and neck. Adult Blanding's turtles have ~n average shell length o'f 9 to 10 inches. HABITAT: Shallow, slow-moving water with mud bottoms and abundant aquatic vegetation are prefers'ed by Blanding's turtles. Extensive marshes bordering rivers provide excellent habitat. In Minnesota, BIt::~ding's turtles are primarily marsh and pond inhabitants but may also be found in streams and lakes. Th:~-~ are frequently found with snapping and painted turtles. Blanding's turtles hibernate on the bottom of ':-'~arshes and ponds. Undeveloped sandy grasslands are vital for nesting sites. Without appropriate nesting habitat populations gradually decline through lack of recruitment of young turtles into the population. LiFE HISTORY: Individuals emerge from overwintering and begin basking in late April on warm, sunny days. Nesting occurs during June in Minnesota. Females are most active in late a~ternoon and at dusk. After traveling up to 1 mile to lay eggs, females may hide near a bush and return lo the marsh the next day, especially in the early morning. The nest is dug by the female in an open sandy area where 6-15 eggs are laid. After a development pedod of approximately two months, hatchlings leave the nest from mid-August to early-October. Often, they must make a long overland trek to find water. Blanding's turtles are mild mannered and do not attempt to bite. If r~olested or threatened they simply pull into their shell and wait for danger to pass. Eggs and young Bla~ding's turtles are eaten by raccoons, skunks, and predatory birds. Adults are particularly vulnerable to being struck by automobiles while crossing roads. RECOMMENDATIONS: The DNR offers the following land use guidelines so that as little harm as poSSible comes to these rare turtles. · Workers should be informed of the presence of Blanding's turtles in the area. · Roads should be kept to minimal standards on widths and lanes. · Roads should be ditched, not curbed or below grade. If curbs must ibe used 4" high curbs at a 3:1 slope are preferred. Blanding's turtles have great difficulty climbing traditional curbs. Curbs and below grade roads trap turtles on the road increasing road kills. When working near wetlands set up silt fencing to keep turtles out of construction areas, it is critical that silt fences be removed after the area has been revegetated. Ditches should not be mowed until after October 1st. Culverts connecting wetland areas should be over-sized and elliptical or box to facilitate turtle movements between wetlands (contact the DNR Nongame Specialist for additional information). Utility access and maintenance roads should be kept to a minimum. Vegetation management under power lines should be done mechanically and between October 1st and June 1st. Chemicals should not be used. Below ground utility construction sites should be returned to odginal grade. Erosion should be prevented from reaching wetlands and lakes. Graded areas should be revegetated with native grasses and forbs. Use of fer'dlizers and pesticides should be avoided. All wetlands should be protected from road run-off, lawn and other chemical run-off by a vegetated buffer strip. We recommend a minimum buffer of 50'. This area shOuld be left unmowed and in a natural condition. Shallow, vegetated wetlands (Type 2 & 3) should not be dredged or deepened. Landscaping should be left as natural as possible, trees should not be planted in known nesting sites. Terrain should be left with as much natural contour as possible, Road placement should avoid separating wetlands from adjacent uplands and should avoid bisecting wetlands. ~ Report sightings of Blanding's turtles to the DNR Regional Nongame Specialist.