themselves, will yield much information on habitat use, population parameters, movements, or 

 home range sizes. Incidental mortalities may be a significant factor over a study long-term 

 enough to yield good information. Additionally, live-trapping to initially find populations will 

 require at least 10 times the effort and cost when compared to snap-trapping, still causing some 

 mortality. Given the very low Sherman live-trapping success, negative results for even 1000 

 trap-nights per site would not provide much confidence that lemmings are not present. 



Dropping boards may provide one option, but we think differentiating northern bog lemming 

 dropping from other voles will be difficult. Jones and Birney (1988) report that northern bog 

 lemming droppings are bright green while other vole droppings are brown or black. However, 

 we found that at least some bog lemmings had brown droppings. If color alone is used to 

 differentiate the droppings, it may lead to serious biases. Pearson (1991) was not confident of 

 identification of droppings (Microtus versus Synaptomys) in a test of the technique in Glacier 

 National Park. He did speculate that it could be possible using more sophisticated identification 

 techniques. 



Snap-trapping for bog lemmings was much more successful than live-trapping and only 3 

 females were captured using this method (at all locations in Montana in 1992 and 1993). It 

 appears to be the method of choice for initial survey work to find new populations, both from an 

 economic and time-constraint view. Concerns have been expressed that snap-trapping is not a 

 suitable teclinique to use on a "sensitive species." This argument may have some validity from a 

 public perception point of view, but has little or no biological basis (Reichel and Beckstrom 

 1993). 



Very small radio-telemetry packages have recently been used to study other voles and this 

 technique seems to hold the most promise for studying Synaptomys. It would require relatively 

 few individuals to be captured and recapture of those individuals would not be necessarj'. It 

 would seem to be the method of choice for examining activity patterns, habitat selection and use, 

 home range size, and typical movements by Synaptomys. 



Long range movements, such as dispersal, are more difficult to determine using radio- 

 telemetry. This is due to 1) the relative rarity of such movements; and 2) time and equipment 

 limitations for finding animals moving far from their expected location. Indirect means of 

 determining the amount of inter-patch movement are available using biochemical analyses of 

 various types to measure gene flow. This may be a viable approach to learning about inter-patch 

 movements and gene flow. 



STATEWIDE MANAGEMENT RECOMMENDATIONS AND RESEARCH NEEDS 



Based on limited observations at the sites where bog lemmings have been found, several interim 

 management recommendations can be made. I feel that these are the minimum necessary to 

 maintain viable bog lemming populations. Additional research is needed which may lead to 

 other management actions necessary for maintaining viable bog lemming populations. 



1) Lacking surveys at specific sites, assume northern bog lemmings are present at sphagnum or 

 other fen^og moss habitat patches in north Idaho and western Montana during land 

 management planning processes. 



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