Agenda - Council - 02/12/2002 - Laserfiche WebLink

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BLA_LN'I)ING'S TLI'RTLE CaE:n, ,'r4, and L. -,e..., ~,. - ..... U~dw.-~ir, ty of Minne"-uta Press, M6~n~a,ooiis for the Nl;nne, s~m Oep[. of Na~m'ai I ,I I I I I I ! I I 'I I I I I 332 Emvdoidea blandingli (Holbrook) ©1988, state of Minnesota. Vera Ming Wong OFFICIAL STATUS: Threatened BASIS FOR STATUS: Although formerly more widespread, the Bland~ ing's turtle is nov., restricted to a small number of staces and provinces in the Upper Midwest. stretching [rom Nebraska eastward to Michigan. On- tario, and Quebec. A smaller remnant population, spanning portions of a few New England states, as well as a number of scattered populations chroughouc the Northeasc. testify to the turtle's more expanded range in earlier times. Minnesota lies on the northwest periphery of the species' range. An extensive area oi"sand dunes and marshes along the Mississippi River. south oi" the town of Kell0gg, is recognized as a maior concentration area for the turtle and may be one of cbc largest breeding populations in its entire range. Elsewhere in the state, the Blanding's turtle has a more spotty distribution, following the Mississippi and St. Croix rivers north- ward into east. central Minnesota and the Minnesota River westw'ard into the south-central portions of the state. Two recent records from ?ipestone County, also confirm the spec/es' presence in the Missouri River drainage 0~' extr~l'l':e ~outh'a.-ester:'i AS a marsh inhabitam the recent destruction of wedand habitats b,~ drain- age and/or inundation for agricultural purposes, river channelization, and wa, tar impoundment has greatly decreased available habitat For the species. Like other turtles, the Blanding's tunic is also vulnerable to collecting as a desirable pet species ISa5 fora t5 to 20 centimeter turtle): it is easily col- lected in are~ where it is abundant, especially during the nesting season. The species' ti& history also makes this turtle particularly susceptible to human disturbances, as evidenced by a long [erm and intensive study or' the population inhabiting the Kellogg Dunes (Fappas. personal communi- cation). Some )~atures contributing co this susceptibility are late matura- tion, tow reproductive potential (one clutch/season), long-lived adults. and high mortality or'eggs and juveniles. Population and reproductive dy- namics suggest viable populations of Blanding's curries are dependent on large numbers or' animals and adequate areas of undisturbed habitat. PREFERRED HABITAT: The preferred habitat of the Blanding's turtle includes calm, shallow water, rich. aquatic vegetation and sandy uplands for nesting. Studies by Congdon et al. (1983) in Michigan and by Linck (personal communication) in Massachusetts have shown that nesting fe- males may travel considerable distances (200 to 400 mete/s) to a nesting area. passing enroute what appears co be suitable nesting habitat immedi- ately adjacent to the marsh [n which they reside. AID TO IDENTIFICATION: Blanding's turtle is medium-sized, averag- ing 15 to 2.5 centimeters in length. The species' most diagnostic field char- acteristics are its smooth, domed upper shell, or CaralSace. and ils bright yellow neck. throat, and chin. The carapace usuall7 appears bluish black. · . with numerous specks of yellow throughout. The lower shell, or plastron, . :': '."f~'bi"igi~t yet-[d~ wld;' bla~'phtches. ~n the ouuide margin. [n general, the ' adult male can be distinguished from the female by its slightly indented plastron and longer tail. The most distinct l'eacure of the plastron is the binge, which allows the turtle to raise the plastron upward and provide more protection to the so~ extremities that it has pulled inside the shell. For chis re,on the species is often referred to as a 'semibox" turtle. RECOMMENDATIONS: Efforts to identify, protect, and preserve pre- forced habitats or' this species should be continued, particularly where populations are totally abundant. Additional information on the species' local distribution and abundance should also be collected to allow an ac- curate assessment of' its current status and to aid in protection efforts. SELECTED RElrERENCES: Breckenridge 1944: Conant 1975: Con- goon et al. t983: Ewert 1982: Graham and Doyle 1977: McCoy 1973: Vogt 198 I. 81anding'~ Turtle: adult viewed from above (rap) and bela'.,. (hnlmml: ',ida view shown in ~ilhouene. -207-