Northern bog lemming survey 1992 A Report to : USDA Forest Service Kootenai National Forest 50 6 U.S. Highway 2 West Libby, MT 59901 Submitted by: James D. Reichel and Stan G. Beckstrom January 1993 Montana Natural Heritage Program 1515 E. 6th Avenue Helena, MT 59620 © 1993 Montana Natural Heritage Program This document should be cited as follows: Reichel^ J.D.^ and S.G. Beckstrom. 1993. Northern bog lemming survey: 1992. Montana Natural Heritage Program. Helena^ MT . 64 pp , TABLE OF CONTENTS TABLES AND FIGURES iii ACKNOWLEDGEMENTS iv INTRODUCTION 1 METHODS AND MATERIALS 3 RESULTS 7 Northern Bog Lemming Survey 7 Sunday Creek Live Trapping 13 Specimens Collected 14 DISCUSSION 16 Distribution 16 Habitat 16 Research Methods 18 Land Management Impacts 2 MANAGEMENT RECOMMENDATIONS AND RESEARCH NEEDS 2 3 LITERATURE CITED 2 6 APPENDICES 28 Appendix A. Data Forms 2 8 Appendix B. Element Occurrence Records 33 Appendix C. Maps of Northern Bog Lemming Sites ... 39 Appendix D. Botanical Community Surveys 45 11 TABLES AND FIGURES Table 1. Sites trapped during 1992 northern bog lemming surveys 5 Table 2. Results of snap trapping during 1992 northern bog lemming surveys 10 Table 3. Results of live trapping during 1992 northern bog lemming surveys 11 Table 4. Success of various baits used in snap traps at sites where northern bog lemmings were found in 1992 . 12 Table 5. Northern bog lemming specimens from 1992 ... 15 Figure 1. Diagram of live trapping and pitfall grid ... 6 Figure 2 . Occurrences of Northern bog lemmings in Montana . 9 111 ACKNOWLEDGEMENTS We would like to thank Bob Summerfield for his help throughout the study. P. Harrington and B.L. Heidel identified plants and plant communities. Help with field work^ location of possible trapping sites^ and other logistical support was provided by M. Burchan^ C.E. Hidy, G. Heinz^ L. Johnson^ J. Jones^ R.L. Krepps^ L.J. Kuennen^ R. Kuennen^ C. Queen^ F.B. Sanchez^ and a large number of other Forest Service personnel. D.L. Center helped with all phases of the project. S. Chadde^ P. Lesica^ and S. Shelly gave advice on bog locations. R.E. Johnson^ Washington State University^ loaned us Museum Special traps for the project. Financial support for the project came from the Kootenai National Forest (U.S. Forest Service) and the Montana Natural Heritage Program (Montana State Library) . IV INTRODUCTION The northern bog lemming ( Synaptomys borealis ) is a small^ grayish brown^ vole-like microtine^ related to the true arctic lemmings (Lemmus) . Nine poorly differentiated subspecies are currently recognized. The northern bog lemming has a total length of 118-140 mm including its very short tail (19-27 mm) (Banfield 1974^ Hall 1981) . The combination of a tail less than 28 mm and a longitudinal grove in the upper incisors distinguish the northern bog lemming from all other mice found in Montana. It is boreal in distribution^ occurring in North America from near treeline in the north south to Washington^ Montana^ Minnesota^ and New England. It typically inhabits sphagnum bogs^ but is also occasionally found in mossy forests^ wet sub-alpine meadows, and alpine tundra. One subspecies ( S.b. artemisiae ) lives on sagebrush hillsides in eastern British Columbia (Anderson 1932) . Southern bog lemmings ( S. copperi ) also inhabit a wide variety of habitats, all of which are marginal for Microtias; bog lemmings may be competitively excluded from better quality habitats by Microtus (Doutt et al . 1973, Linzey 1981) . The northern bog lemming is rarely trapped and is one of the least known mice in North America. A few relict populations occur in the lower 48 states; the subspecies chapmani occurs in Montana, Idaho, and northeast Washington (Hall 1981) . Bog lemmings are known from 4 locations in Idaho and 8 in Washington, all from within 80 km of the Canadian border (Johnson and Cheney 1953, Wilson et al . 1980, Reichel 1984, Groves and Yensen 1989^ D. Johnson pers . comm.) . Prior to 1992^ evidence of bog lemmings in Montana included: 1) 2-3 locations on the west side of Glacier National Park (Wright 1950^ Weckwerth and Hawley 1962^ Hoffmann et al . 1969); 2) Shoofly Meadows in the Rattlesnake drainage north of Missoula (Adelman 1979) , and 3) a single skull recovered from a Boreal Owl ( Aegolius funereus ) pellet west of Wisdom (J. Jones pers. comm.) ; where the owl captured the lemming was unknown. The reasons for the disjunct nature of the populations may include: 1) the localized nature of its primary habitat; and 2) the currently patchy distribution of a boreal species that was more widely distributed during the Pleistocene (a glacial relict) . The U.S. Forest Service, Region 1, lists the northern bog lemming as Sensitive. The species is listed as a Species of Special Concern by the Montana (Genter 1992) and Idaho Natural Heritage Programs (Moseley and Groves 1990) . SI is defined as: ^^critically imperiled because of extreme rarity (5 or fewer occurrences, or very few remaining individuals) , or because of some factor of its biology making it especially vulnerable to extinction." This has been changed to S2 following the 1992 survey. S2 is defined as ^^imperiled because of rarity (6 to 20 occurrences), or because of other factors demonstrably making it very vulnerable to extinction throughout its range . " We began a study of northern bog lemmings in Montana in 1992. Objectives the first year of the study included: 1) surveying at least 15 sites with potential habitat for bog lemmings in northwest Montana^ concentrating on the Kootenai National Forest; 2) determining efficient and effective survey techniques; and^ 3) describing habitat where bog lemmings were found. METHODS AND MATERIALS We surveyed riparian habitats for bog lemmings. Most sites sampled were suggested by botanists^ plant ecologists^ biologists and others from the U.S. Forest Service and Montana Natural Heritage Program (MTNHP) . Others were identified while in the field or by examining maps of the general areas we were to visit. From 17 June - 21 August 1992 we used Museum Special snap-traps^ Sherman live-traps^ and/or pitfalls (#10 tin cans) to sample 21 sites in western Montana (Table 1) . Traps were baited with a combination of peanut butter and rolled oats^ either alone or with one of 5 other baits: 1) apples and carrots; 2) Hawbaker's muskrat lure; 3) Hawbaker' s food lure; 4) E.J. Dailey' s muskrat lure; or 5) E.J. Dailey' s muskrat lure #2. Relative success of baits used was examined using the G test (Sokal and Rohlf 1969) . Two traps with different baits were placed within 2 m of each other at each station. We placed each trap at a location to maximize success (runway^ burrow^ etc.) . Stations were placed 5-20 m apart. At sites where northern bog lemmings were not caught^ trapping effort ranged from 240 to 556 trap nights over 2-4 nights. A trap night is equivalent to one trap set for one 24-hour period (traps sprung and empty^ or completely missing^ are not counted) . During the period 4-7 July 1992 we ran a snap trap line in a meadow and adjacent forested area located along Sunday Creek. Portions of this trap line were picked up when a bog lemming was captured. At subsequent sites^ all traps were removed when the first bog lemming was captured. Following the initial capture of northern bog lemmings at Sunday Creek^ we set up a 9x9 live trap grid with 15 m spacing. Two Sherman live traps were set at each station and baited with peanut butter and oatmeal; one of the traps at each station had E.J. Dailey' s muskrat lure added to the peanut butter and oatmeal. Within the live trap grid^ a 5x5 pitfall grid was established with approximately 15 m spacing (Figure 1) . All traps (including pitfalls) contained cotton or polyester batting for nesting material. Traps were checked twice daily. All mice caught were toe clipped with individual combinations^ weighed^ measured, examined for reproductive status, and released. The first trial of this live-trap grid was run from 21-24 July 1992 (pitfalls were run from 22-24 July) . The grid was run again on 17-21 August 92. During the second period, traps were baited with peanut butter and oatmeal; one trap at each station had E.J. Dailey' s muskrat lure added to the peanut butter and oatmeal, the other trap had E.J. Dailey' s muskrat lure #2 added (peanut butter : oatmeal : lure = 30:20:1) . Table 1. Sites trapped during 1992 northern bog lemming surveys. Site Trap nights Elev- Date snap live pit T32N R2 6W 513 4800 4-7 July 361 21-24 July 477 50 17-21 Aug 638 100 T32N R2 6W S20 3900 3-7 July 428 T34N R26W S14 3400 3 Jun-4 Jul 387 T3 4N R25W S7 3020 3 Jun-4 Jul 288 T34N R25W S35&36 3300 30 Jun-4 Jul 324 T37N R25W S32 5600 7-10 July 240 T37N R24W S19 5600 7-10 July 252 T37N R3 3W S18 6200 26 July 5 T37N R33W S13&24 4300 24-27 July 423 T33N R32W S24&25 3600 21-25 June 250 200 T33N R31W S6&7 4200 21-25 June 150 240 T3 3N R31W 828 3400 21-25 June 150 *200 T28N R30W S25 4200 17-21 June 553 3 T2 6N R31W S6 3800 3-5 Aug 290 T31N R2 6W SI 4760 18-19 Aug 114 T32N R22W S35 4600 21-23 July 272 TIN R17W S31 8100 13-17 July 306 TIS R18W S2 7840 13-17 July 404 TIS R18W S2 7360 15-18 July 279 TIS R17W S26 6520 13-15 July 140 TIN R18W SIO 5920 17-18 July 97 KOOTENAI NATIONAL FOREST Fortine District #*Sunday Creek, Lincoln Co, #Twin Meadows Creek, Lincoln Co. #Dudley Slough, Lincoln Co. #Ant Flats, Lincoln Co. # Jumbo Lake, Lincoln Co. #Big Therriault Lake, Lincoln Co. #Divide Creek, Lincoln Co. Three Rivers District *Hawkins Pond, Lincoln Co. #Pete Creek Meadow, Lincoln Co. Libby District Loon Lake, Lincoln Co. Rainbow Lake, Lincoln Co. #Tom Poole Lake, Lincoln Co. Tepee Lake, Lincoln Co. CeQ^inet District Rock Creek Meadow, Sanders Co. FLATHEAD NATIONAL FOREST Tally Lake District *Bowen Creek, Lincoln Co. Hellroaring Basin, Flathead Co. BEAVERHEAD NATIONAL FOREST Wisdom District Schultz Crk trib., Beaverhead Co. Schultz Saddle, Beaverhead Co. Tie Creek meadows, Beaverhead Co. *Maybee Meadows, Beaverhead Co. BITTERROOT NATIONAL FOREST Sula District *Meadow Creek, Ravalli Co. Grand Total 5160 2308 153 *= Synaptomys found at this site #= Plant community survey done at this site Figure 1. Diagram of live trapping and pitfall grid. L = Sherman live trap; P = pitfall trap. < 120 m 120 m LLLLLLLLL LLLLLLLLL P P P P P LLLLLLLLL P P P P P LLLLLLLLL P P P P P LLLLLLLLL P P P P P LLLLLLLLL P P P P P LLLLLLLLL LLLLLLLLL V L L L L L L L L Open water; no trap set Pam Harrington of the MTNHP conducted botanical surveys at 8 trapping sites during 7-12 July 1992 (Appendix B) . ECODATA methodology was used for botanical surveys (DeVelice 1991) . Additionally, Bonnie Heidel, MTNHP botanist, conducted a brief vegetative survey of the Maybee Meadows site on 24 October 1992. RESULTS Northern Bog Lemming Survey . Northern bog lemmings were captured at 5 (Figure 2) of the 21 sites trapped (Tables 1,2,3) . Elevation of the sites where bog lemmings were captured ranged from 4760-6520 feet (1535-2100 m) . Northern bog lemmings were caught either in, or very close to, thick mats of sphagnum moss ( Sphagnum spp . ) . Sphagnum moss seemed to be the most reliable indicator of a potential site. Some sites where bog lemmings were caught had an open overstory of subalpine fir ( Abies lasiocarpa ) and/or spruce (Picea) ; others were without a tree component. Bog birch ( Betula glandulosa ) and\or a dwarf willow (Salix sp . ) were present at all sites. At Maybee Meadows the moss hummock habitat was dominated by Sphagnum in the ground cover layer; Carex utricularia in the herbaceous layer; and Salix planifolia in the short shrub layer. Bog lemmings at the Sunday Creek site were caught in two community types: 1) a Salix drummondiana community with only 10% S . d. canopy cover; and 2) a Abies lasiocarpa community, Calamagrostis canadensis phase, with canopy cover of 40% A. 1 . (overstory) and 60% Betula glandulosa (shrub layer) . Moss ground cover was 50-60% and 30-50 cm thick (Appendix B) . Plant community surveys were completed on 8 trapping sites (Table \f Appendix B) . The Sunday Creek site was the only site with bog lemmings which had a plant community survey completed; other lemming sites were located too late in the year for plant community surveys to be scheduled. The remaining four sites where bog lemmings were captured will have plant community surveys completed in 1993. Snap trap effort required to document bog lemming presence at sites containing the species ranged from a maximum of 140 trap nights (during 2 nights of trapping) down to 5 ^^trap nights" (120 traps from noon to 1 p.m.) . In contrast^ areas where no bog lemmings were found received 240-556 trap nights of effort. At sites where northern bog lemmings were captured^ we averaged 1.67 lemmings per 100 trap nights. A mixture of Dailey' s muskrat lure mixed with peanut butter and oatmeal appeared more effective at capturing northern bog lemmings than other baits used (Table 4)^ but differences were not significant (G = 3.44, 3 df) . During bog lemming surveys, at least 13 other species of small mammals were captured (Tables 2,3) . All Sorex palustris were identified in the field; a few of the smaller Sorex species were also identified and all were Sorex cinereus . The complete inventory of shrew captures (by species) will have to wait for the specimens to be prepared and the skulls keyed out. Figure 2. Occurrences of Northern bog lemmings in Montana ^ Occurrences of the NORTHERN BOG LEMMING in Montana j|^ 1992 sites /\ Historic sites Maybee Meadows v, v Table 2. Results of snap trapping during 1992 northern bog lemming surveys ^ Site Trap Total number of each species caught Nights SOPA SOSP MILO MIPE MIRI PHIN SYBO CLGA ZAPR PEMA TASP THTA Bowen Creek 114 2 1 1 Sunday Creek 361 10 1 2 5 1 Rock Ck Meadow 290 1 1 3 Hawkins Pond 5 1 2 Schultz Ck Trib. 306 2 10 3 7 1 Schultz Saddle 404 7 9 5 6 2 2 Tie Ck meadows 279 21 3 7 1 Meadow Ck 97 2 1 1 1 Maybee Meadows 140 1 8 4 4 Hellroaring Bas . 272 4 4 13 2 3 1 5 6 Pete Ck Meadow 423 3 6 1 1 1 11 Loon Lake 250 3 1 14 4 3 1 Rainbow Lake 150 1 1 1 Tom Poole Lake 150 3 27 1 Twin Meadows Ck 428 16 1 24 14 7 2 Dudley Slough 387 2 12 12 Ant Flats 288 2 1 Jumbo Lake 324 4 3 11 5 2 2 Big Therriault 240 7 1 5 3 7 3 1 Divide Creek 252 8 2 3 31 4 4 Grand Total 5160 5 71 8 164 10 62 12 62 28 18 18 1 SOPA=Sorex palustris; SOSP=Sorex spp . ; SYBO=Synaptomys borealis; MlLO=Microtus longicaudus; MIPE=Microtus pennsylvanicus; MIRI=Microtus richardsoni; PHIN=Phenacomys intermedius; CLGA=Clethrionomys gapperi; ZAPR=Zapus princeps; PEMA=Peromyscus maniculatus; TASP=Tamias spp.; THTA=Thomomys talpoides. Table 3. Results of live trapping during 1992 northern bog lemming surveys (includes pitfalls and Sherman live-traps) . Site Trap Nights Total Number of each species caught (including recaptures) Pit. Sher. SOSP MILO MIPE PHIN SYBO CLGA ZAPR PEMA NEC I MUFR AMMA RAPR BUBO Sunday Creek 21-24 July 92 50 477 7 1(1) 3 3 17-21 Aug 92 100 638 18 4 0(1) 5 7 1 7 3 10 Loon Lake 200 1 4 3 1 Tepee Lake 3 553 11 5 23 26 1 4 1 Rainbow Lake 240 5 4 4 Tom Poole Lake 200 4 5 Grand Total 153 2308 46 36 1(2) 34 15 10 10 ( ) = number of Synaptomys caught in a pitfall SOSP=Sorex spp.; MILO=Microtus longicaudus; MIPE=Microtus pennslyvanicus; PHIN=Phenacomys intermedius; SYBO=Synaptomys borealis; CLGA=Clethrionomys gapperi; ZAPR=Zapus princeps; PEMA=Peromyscus maniculatus; NECI=Neotoma cinerea; MUFR=Mustela frenata; AMMA=Amby stoma macrodactylum; RAPR=Rana pretiosa; BUBO=Bufo boreas . 2 1 48 1 68 2 Table 4. Success of various baits used in snap traps at sites where northern bog lemmings were found in 1992. ^PR ^ O Dailev^s D.^s #2 Haw. Musk. Site T-N Sybo T-N Sybo T-N Sybo T-N Sybo Bowen Creek 5 6 1 58 Sunday Creek 180 2 181 3 Hawkins Pond 2 Meadow Creek 4 9 Maybee Meadows 72 2 Grand Total 303 4 174 5 58 181 #Sybo/100 trap nights 1.32 2.9 0.00 1.7 ^ PB&O = peanut butter and oatmeal; Dailey' s = Dailey' s muskrat lure, peanut butter and oatmeal; D.'s #2 = Dailey' s muskrat lure #2, peanut butter and oatmeal; Haw. Musk. = Hawbaker's muskrat lure, peanut butter and oatmeal; T-N = number of trap nights; Sybo = number of Synaptomys borealis captured. Additionally^ some voles specimens^ particularly subadults^ will need verification of species when the skulls are cleaned. At the five sites where bog lemmings were captured, 0-3 other species of voles were also captured (Table 2) . These included the meadow vole ( Microtus pennsylvanicus ) , heather vole ( Phenacomys intermedius ) and red-backed vole ( Clethrionomys gapperi ) . Red-backed voles were captured at higher/dryer micro-sites than bog lemmings, in all cases either in a forest habitat or within 10 m of a forest edge. Red-backed voles were not captured in thick sphagnum mats. Heather voles were captured in a variety of upland and riparian habitats. Meadow voles were caught almost exclusively in wet, open habitats. At the two southern sites, both heather and meadow voles were caught with the northern bog lemmings in a mosaic of sedge meadow and sphagnum moss mats. At Bowen Meadows one meadow vole was caught in sphagnum, while no meadow voles were caught snap trapping at either Sunday Creek or Hawkins Pond within the sphagnum areas . We found that snap trap capture rates of all voles in combination (including bog lemmings) were 40% higher at sites where no bog lemmings were captured than at those where they occurred (6.4 vs 4.6 per 100 trap nights) . While we did not record numbers of trap-nights per habitat, we observed trapping success in sphagnum habitat to be much lower than in non-sphagnum habitats. Sunday Creek Live Trapping. During the July 21-24 live trapping at Sunday Creek, one bog lemming was captured in a pitfall at night and 13 one in a Sherman live-trap during the day. Both died in the traps. While opening pitfalls and setting traps in August^ we found several pitfall covers had been knocked off since the July trapping period. One bog lemming had died in a pitfall as a result of this. During the week^ one bog lemming was captured in a pitfall^ marked and released. Northern bog lemming capture rates for these two periods were: 0.09 per 100 trap nights in Sherman live traps; and 1.33 per 100 trap nights in pitfalls. In an effort to increase live trap success rates^ the bedding material from the bog lemming captured in the pitfall in August was divided and added to 8 Sherman traps (olfactory enticement) in nearby micro-sites with thick sphagnum mats. No additional bog lemmings were captured as a result. Specimens Collected. A total of 15 northern bog lemmings specimens will be placed in one or more regional university museums (Table 5) . All but one will be prepared as skins and skulls/skeletons; one lemming captured in a pitfall was not satisfactory for a skin and will be a skeleton only. Stomachs were collected from 14 specimens and will be analyzed in the next year. Only one female was collected. We noted that droppings from some specimens were bright green^ however^ at least 2 individuals had brown droppings . 14 Table 5. Northern bog lemming specimens from 1992. Site Date # Sex Type Sunday Creek, T32N R2 6W ' S13 5-Jul SGB 4 M Si, Se, St AA SGB 5 M AA 6-Jul SGB 6 M AA 7-Jul SGB 7 M AA AA SGB 8 M AA 22-Jul JDR 3164 M Si, Se, (St, Ki) 17 -Aug to do 7 Se Maybee Meadows 15-Jul SGB 9 M Si, Se, St TIS R17W S26 15-Jul SGB 10 M AA \A 15-Jul SGB 11 M AA AA 15-Jul SGB 12 F AA Meadow Creek TIN R18W SIO 18-Jul SGB 13 M Si, Se, St Hawkins Pond 26-Jul JDR 3165 M Si, Se (St, Ki) T37N R33W S18 '' JDR 3166 M Bowen Creek 19-Aug to do M (Si, Se, St, Ki) T31N R2 6W SI Si = Skin Su = Skull Se = Skeleton St = Stomach Ki = Kidney DISCUSSION Distribution . The Maybee Meadows site is the southern-most site known for the species outside of New England; two sites in New Hampshire are about 160 km farther south (Clough and Albright 1987) . The Maybee Meadows site is also the only known northern bog lemming site east of the Continental Divide in Montana. Bog lemmings are now known from across the northwest corner of the state and south through the mountains to near Lost Trail Pass on the Continental Divide. We expect additional populations to be found across western Montana^ perhaps as far south as Yellowstone National Park^ east to the Rocky Mountain Fronts and possibly even in some eastern mountain ranges such as the Belt or Snowy ranges. Elevations from which bog lemmings are now known in Montana^ range from 3800 feet (Camas Creek^ Wright 1949) up to 6520 feet (Maybee Meadows) . Populations of northern bog lemmings in the northwest U.S. have apparently been isolated since the last ice age ended over 10^000 years ago. It seems likely lemming populations were more wide-spread at that time^ then were reduced in size and number during the Hypsithermal 6000-3000 years ago^ when the climate was warmer than at the present time. Habitat . Bog lemmings at Sunday Creek were caught in two community types: 1) a Salix drummondiana community and 2) a Abies lasiocarpa community, Calamagrostis canadensis phase. Moss ground cover was 50- 60% and 30-50 cm thick (Appendix B) . However, peatland communities 16 are a very small proportion of the landscape in the region and have not been adequately classified (Bursik and Moseley 1992) . It is doubtful that bog lemming distribution will be mirrored by plant community distributions using current definitions. At our first three new bog lemming sites^ all bog lemmings were caught in sphagnum moss mats^ despite more traps being placed in other adjacent habitats. This helped us develop a ^^search image" for additional potential bog lemming populations^ and directly contributed to our choices of Bowen Creek and Hawkins Pond as trapping sites. Previous habitat descriptions of S .b . chapmani trapping sites in the northern Rocky Mountains have sometimes included mention of sphagnum moss (Layser and Burke 1973^ Groves and Yensen 1989) while others have not (Wright 1950^ Weckwerth and Hawley 1962^ Wilson et al . 1980) . JDR spent several hours along Camas Creek in the vicinity of the first lemming population known from the state (Wright 1950) and found only scattered clumps of moss. Weckwerth and Hawley (1962) did not describe the specific sites where they captured bog lemmings. JDR captured a single juvenile male lemming on a dry alpine/subalpine ridge in northeast Washington (Wilson et al . 1980) . We believe that areas with extensive sphagnum mats are the most likely sites in which to find new bog lemming populations in Montana. Other habitats may support lower densities of bog lemmings; may be 17 used primarily by dispersing individuals; may be used during specific seasonal^ climatic^ or competitive situations; or may be population sinks. The only certainty is that there is much to be learned about habitat use by northern bog lemmings . Research Methods. How do we get the information on distribution^ habitat use^ and movement we need to manage this species? Distributional information^ and to a lesser extent habitat use^ has often been gathered using snap-traps. Detailed habitat use and movement data is most commonly obtained using mark-recapture techniques with live traps. However^ for northern bog lemmings^ live traps are of very limited usefulness. This is because Sherman live- trap use: 1) is labor intensive throughout the trapping period; 2) has very low success with any bait tried; and 3) results in at least some mortality (the single animal caught died in the trap) . Pitfalls^ as live traps: 1) are labor intensive especially during placement; 2) cannot be used in the saturated soil situations commonly encountered in bog lemming habitat; and 3) result in at least some mortality during and between trapping periods. Given these drawbacks^ it seems doubtful that live-trapping methods^ by themselves^ will yield much information on habitat use^ population parameters^ 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 take at least 10 times the effort and cost when 18 compared to snap-trapping and will still cause some mortality. Given the very low Sherman live-trapping success^ negative results for even 1000 trap-nights per site would not give 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. Snap-trapping for bog lemmings was much more successful than live-trapping and only 1 female was captured using this method (at all locations in Montana in 1992) . 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 technique 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. Voles, including northern bog lemmings, show r-selected traits, eg. rapid development, early reproduction, high reproductive rates, short life span. These are related to the selection pressures of the high natural mortality suffered by voles, which are food for a large number of predatory vertebrates. For example, bog lemmings made up 1-2% of marten (Martes americana) diets in Glacier National Park, 19 while comprising only 0.2% of small mammals trapped (Weckwerth and Hawley 1962) . The current bog lemming populations in Montana have survived thousands of years of isolation^ predation by dozens of species^ climatic changes^ and catastrophic events such as fires. The chances that taking 1-5 individuals from a site would significantly affect the population approaches zero. We believe that the small possibility of a negative effect is far outweighed by the knowledge of the existence of the population. The chances of major negative effects to a undiscovered lemming population taking place due to land management decisions^ is far higher. The Sunday Creek population provides an example of how land management decisions may affect bog lemming populations. Land Management Impacts. The Sunday Creek area seems typical of northern bog lemming populations^ with patches of suitable habitat strung out along a drainage. In the past^ when one subpopulation was lost^ the habitat patch could be recolonized from adjoining subpopulations . Beaver alternately created and destroyed habitat patches along the drainage via flooding with dams^ but dispersal from adjacent areas on the drainage provided inhabitants for the new habitat patches. Fires swept through the area^ drying out areas to some extent. However^ this drying out was probably reduced somewhat by the timber in the stream bottom being more resistant to fire than that on the slopes above. This dynamic process has lasted thousands of years. However, the Sunday Creek population of lemmings may now be in danger of extirpation. 20 Habitat patches we viewed as ^^good" appeared to span the length of Sunday Creek from our original lemming capture location (T32N^ R26W^ center of Section 13) downstream to Harvey Creek (T33N^ R25W^ Section 25) with gaps of less than 1.5 km between patches. However^ from the Sunday Creek crossing at FS 315 (T32N, R26W, Section 6, NE 1/4) downstream^ the habitat has been substantially reduced and degraded. In Paul Creek^ a tributary of Sunday Creek^ this has also occurred. It appears that substantial amounts of good bog lemming habitat occurred in Paul Creek drainage at least for 3 km up from the confluence with Sunday Creek. These bog areas have dried out and much of the habitat now appears marginal. Two management actions appear to have caused the habitat reduction and degradation along Paul Creek and lower Sunday Creek^ grazing and timber harvest. Grazing is very heavy over much of the riparian habitat from the Sunday Creek crossing of FS-315 downstream. Where large acreages apparently had suitable habitat in the past^ much of the area has been converted to introduced plants^ often eaten down to 1" tall or less. This process can be seen at the few remaining sphagnum patches. Since sphagnum moss and many of the associated sedges appear unpalatable to cattle^ the habitat is first damaged by trampling as cattle cross the habitat. These trampled areas allow invasion by exotic plant species. Many of these invaders are eaten by cattle^ resulting in more trampling and acceleration of the process. Both soil and hydrology may be changed in a very long-term 21 fashion^ and habitat recovery may be very slow in the short-term (decades) even with total exclusion of cattle and intensive rehabilitation . Timber harvest has been extensive in the drainage in this area. Clearcuts extend from high up on the valley slope^ down onto the flood plain; in some areas no trees remain in the riparian area. Remnant wetland plants are now found in very dry areas. Apparently the heavy removal has changed the timing of the runoff^ with a flush of water in spring and little retention into summer. Areas that had access to water or saturated soils nearly all year are now dry by early to mid-summer. Additionally^ floodplain areas which had tree cover and thus shading to maintain cool^ damp microsites^ have been opened up and now dry out quickly. Timber harvest alone may not eliminate large areas of habitat . However^ the cumulative effects of several new factors combined with the changing moisture regime^ may eliminate large potential habitat areas over the long-term. Grazing and soil compaction by cattle^ coupled with invading plants^ is in the process of completely eliminating patches of habitat from section 34 downstream on Sunday Creek (most of which is privately owned land) . This would completely isolate habitat in Paul Creek. If bog lemmings were extirpated in Paul Creek it is unlikely they could re-populate it from upper-Sunday Creek. Minimum patch sizes and possible dispersal distances are not known for bog lemmings. However^ we estimate the current suitable 22 habitat to be less than 50% of what was typical of the drainage prior to the past 50 years. With the reduced habitat^ comes increased dispersal distances between patches. Additionally^ the large areas with very short vegetation due to overgrazing probably are severe barriers to dispersal. The habitat at the Meadow Creek lemming site is also being affected by cattle grazing. Suitable bog lemming habitat containing sphagnum moss was estimated to cover about 10 acres^ with only sparse^ very marginal habitat present downstream for about 3 km and none upstream. Trampling and grazing around the edge of the site has severely degraded at least 1 acre of prime habitat. Much of the soil that once was covered with sphagnum^ is now exposed and drying out. Similar but lesser impacts were also observed at Maybee Meadows. MANAGEMENT RECOMMENDATIONS AND RESEARCH NEEDS Based on limited observations at the sites where bog lemmings were found we would make several interim management recommendations. We feel these are the minimum necessary to maintain viable bog lemming populations. Additional research is needed and may suggest other management actions which will be necessary for maintaining viable bog lemming populations. 1) Assume northern bog lemmings are present on all National Forests in Montana (except Custer N.F.) during land management planning processes . 23 2) Do not harvest timber within 100 m of sphagnum mats or associated streams and wetlands. 3) Minimize domestic livestock grazing in drainages with sphagnum mats present. Range conditions in riparian areas with sphagnum mats should be maintained in good to excellent categories. If current range condition is fair or poor^ stocking rates should be reduced to a point where rapid recovery occurs . Very little information is available on the northern bog lemming. Even the distribution in the U.S. is poorly understood; most populations have been found within the past 15 years. Habitat use by northern bog lemmings has never been determined in any systematic way. Descriptions of habitat in the U.S. consist of anecdotal accounts of where each specimen has been captured; only about 30 individuals had been collected in the Pacific Northwest prior to this study. Food habits and reproductive information also are limited to a very few anecdotal accounts. No information is available on such subjects as movements^ population densities^ longevity, or home range. Much additional research is required to make intelligent land management decisions where northern bog lemmings are present. We recommend the following as the highest priority needs : 1) Develop an annotated bibliography of northern bog lemming literature. The literature should be summarized including 24 information on habitat^ reproduction^ and success of trapping methods. Distribute this information to significant land management agencies in the Pacific Northwest. 2) Conduct additional surveys to better understand distribution in Montana. Analyze all stomachs of bog lemmings collected to provide food habits information. 3) Conduct plant community surveys at all known bog lemming locations. This should include identification of dominant mosses present. 4) Gather information on the requirements of the mosses found to be dominant on the bog lemming sites. 5) Carry out research on northern bog lemming habitat use. Given the extreme difficulty in capturing northern bog lemming we feel radio-telemetry is the only viable means to obtain satisfactory answers as to how bog lemmings use habitat within their home ranges . 6) Carry out research on northern bog lemming movements to gather information on home ranges and possibly dispersal. This information needs to be integrated with simultaneously collected habitat use data. Again^ we feel radio-telemetry is the only viable methodology available. 25 LITERATURE CITED Adelman^ E.V. 1979. A survey of the nongame mammals in the Upper Rattlesnake Creek drainage of Western Montana. M.S. Thesis, University of MT, Missoula. 129 pp. Anderson, R.M. 1932. Five new mammals from British Columbia. Natl. Mus. Can. Bull 70:99-107. Banfield, A.W.F. 1974. The mammals of Canada. University of Toronto Press, Toronto. Bursik, R. and R.K. Moseley. 1992. Prospectus: Valley peatland ecosystem project, Idaho. Idaho Dept . Fish Game, Conserv. Data Cntr. Boise, Idaho. Unpubl . 16 pp. Clough, G. C. and J. J. Albright. 1987. Occurrence of the northern bog lemming, Synaptomys borealis , in the northeastern United States. Canadian Field Naturalist 101:611 613. DeVelice, R.L. 1991. MTNHP site and community survey manual, version 91B. Mont. Nat. Heritage Pro., Helena, Mont. Doutt, U.K., C.A. Heppenstall, and J.E. Guilday. 1973. Mammals of Pennsylvania, 3rd edition. Penn. Game Comm., Harrisburg. 283 pp. Center, D.L. 1992. Animal species of special concern. Unpubl. Rep., Mont. Nat. Heritage Prog., Helena. 9 pp. Groves, C. and E. Yensen. 1989. Rediscovery of the northern bog lemming ( Synaptomys borealis ) in Idaho. Northw. Nat. 70:14-15. Hall, E.R. 1981. The mammals of North America, 2nd edition, 2 vols., John Wiley and Sons, New York. Hoffmann, R.S., P.L. Wright andF.E. Newby. 1969. The distribution of some mammals in Montana 1. Mammals other than bats. J. Mammal. 50:579-604. Johnson, M.L. and P.W. Cheney. 1953. Synaptomys in Idaho and northeastern Washington . Murrelet 34:10. Jones, J.K., Jr., and E.G. Birney. 1988. Handbook of mammals of the north-central states. U. Minn. Press, Minneapolis. Layser, E.F. and T.E. Burke. 1973. The northern bog lemming and its unique habitat in northeastern Washington. Murrelet 54:7-8. 26 Linzey^ A.V. 1981. Patterns of coexistence in Microtus pennsylvanicus and Synaptomys copperi . Unpubl . Ph.D. dissert.^ Virg. Polytechnic Inst, and State Univ.^ Blacksburg. 97 pp. Moseley^ R. and C. Groves. 1990. Rare^ threatened and endangered plants and animals of Idaho. Unpubl. Rep.^ Nat. Heritage Sect . ^ Nongame and Endangered Wildl. Prog.^ Idaho Dept . Fish Game^ Boise. 33 pp . Reichel^ J.D. 1984. Ecology of Pacific Northwest alpine mammals. Ph.D. thesis^ Washington State Univ.^ Pullman. 91 pp. Sokal, R.R. and F.J. Rohlf. 1969. Biometry. W.H. Freeman and Co . , San Francisco, California. 776pp. Weckwerth, R.P. andV.D. Hawley. 1962. Marten food habits and population fluctuations in Montana. J. Wildl. Manage. 26(1) :55 74. Wilson, C, R.E. Johnson and J.D. Reichel. 1980. New records for the northern bog lemming in Washington. Murrelet 61:104-106. Wright, P.L. 1950. Synaptomys borealis from Glacier National Park, Montana. J. Mammal. 31:460. 27 APPENDICES Appendix A. Data Forms 28 Data Sheet - Small Mammal Snap Trapping . of Date ^iiae Biologist_ Gen. Location _^ rp N R_ ^ Section^ "?Sp'rwind dir . speed, cloud c...r, precxp last 24 l>rs) List all individuals caught under the_tYpe_of_balt_used___ Bait ft T->-^r-^ #Snapped_ 29 Data Sheet - Small Mammal Live Trapping of Date Time Biologist Gen. Location T N R W Section Weather (Temp., wind dir & speed, cloud cover, precip last 24 hrs) Species Alive/Dead? Grid/Trap # Trap type Bait_ Sex Repro. (scrotal, perforate, lactating, etc) Wt. Tot. Len. Tail len. Ear L. Hind Ft. Len. [ Marked today? MARKING: Front Rear (ie. RF3) (ie. LH2) Species Alive/Dead? Grid/Trap # Trap type Bait_ Sex^ Repro. Wt. Tot. Len. Tail len. Ear L. Hind Ft. Len. Marked today?, MARKING: Front Rear Species Alive/Dead? Grid/Trap # Trap type Bait_ Sex____ Repro. ^ Wt. Tot. Len. Tail len. Ear L. Hind Ft. Len. Marked today ?^ MARKING : Front. Rear NOTES : 30 Species_ Grid/Trap #_ Sex Alive/Dead? Trap type Bait_ Repro, Wt, Tot . Len . (scrotal , perforate, lactating, etc) Tail len. Ear L. Hind Ft. Len. Marked today ?^ MARKING: Front Rear (le. RF3) ( ie . LH2 ) Species_ Grid/Trap #_ Sex Wt. Al ive/Dead? Trap type Bait_ Tot, Hind Ft. Len. _ Repro. Len. Tail len._ Marked today?^ Ear L. MARKING: Front_ Species Rear Grid/Trap #^ Sex Wt. Hind Ft. Len. Al ive/Dead? Trap type Bait_ Repro, Tot. Len, Tail len, Ear L. Marked today ?_ MARKING: Front_ Species Rear Grid/Trap # Sex Wt. Tot, Hind Ft. Len. Alive/Dead? Trap type Bait_ Repro. Len. Tail len.^ Marked today?_ Ear L. MARKING: Front_ NOTES : Rear 31 LOCATION DATES Instructions for filling in Small Mammal Data Sheet Indicate number of sheets used for this checking session Date: Use formate 13 Jun 92 Time: Use formate 0930 Weight: in grams (or tenths of grams) Total Length: in mm from nose tip to tail vertebra tip with animal stretched on dorsal side Tail length: in mm from where tail enters body to tip of tail vertebra (hold tail at right angle (up) from body Ear length: in mm from the deepest part of the notch to tip of ear pinna Hind foot length: in mm from heel bone to end of longest toenail Reproduction: 1) males: testes scrotal or inguinal ; 2) females: perforate or imperforate; if perforate, lactating or not and nipple size. Marking with toe clipping: \ Left "i Right Left Front H (feet viewed from above) LFl RHl LFl LHl RFl RHl RFl LHl LFl RH2 LFl LH2 RFl RH2 . RFl LH2 LFl RH3 LFl LH3 RFl RH3 RFl LH3 LFl RH4 LFl LH4 RFl RH4 RFl LH4 LFl RH5 LFl LH5 RFl RH5 RFl LH5 LF2 RHl LF2 LHl RF2 RHl RF2 LHl LF2 RH2 LF2 LH2 RF2 RH2 RF2 LH2 LF2 RH3 LF2 LH3 RF2 RH3 RF2 LH3 LF2 RH4 LF2 LH4 RF2 RH4 RF2 LH4 LF2 RH5 LF2 LH5 RF2 RH5 RF2 LH5 LF3 RHl LF3 LHl RF3 RHl RF3 LHl LF3 RH2 LF3 LH2 RF3 RH2 RF3 LH2 LF3 RH3 LF3 LH3 RF3 RH3 RF3 LH3 LF3 RH4 LF3 LH4 RF3 RH4 RF3 LH4 LF3 RH5 LF3 LH5 RF3 RH5 RF3 LH5 LF4 RHl LF4 LHl RF4 RHl RF4 LHl LF4 RH2 LF4 LH2 RF4 RH2 RF4 LH2 LF4 RH3 LF4 LH3 RF4 RH3 RF4 LH3 LF4 RH4 LF4 LH4 RF4 RH4 RF4 LH4 LF4 RH5 LF4 LH5 RF4 RH5 RF4 LH5 Right Hindfoot 32 Appendix B. Element Occurrence Records 33 SYNAPTOMYS BOREAL IS ^002 NORTHERN BOG LEMMING Global rank: G5 State rank: S2 Forest Service status : Federal Status SENSITIVE Survey site name: EO rank: EO rank comments: HAWKINS POND B QUALITY GOOD; SIZE SMALL BUT MAY CONTINUE DOWNSTREAM. County: LINCOLN USGS quadrangle: NORTHWEST PEAK Township: Range: Section: TRS comments 037N 033W 18 SE4NE4 Survey date: 1992-07-26 Elevation First observation: 1992-07-26 Slope/aspect Last observation: 1992-07-26 Size (acres) 6190 LEVEL Location: PURCELL MOUNTAINS; FROM YAAK TAKE FS RD 33^ ^20 MI TO SITE, Element occurrence data: --10 SEEN; A LOT OF SIGN (CUTTINGS, DROPPINGS, RUNWAYS; HAND; SCROTAL MALE TRAPPED. 1 CAUGHT BY General site description: POND AREA FILLING IN; OPENING IN SUBALPINE FIR FOREST. GROUND COVER ABOUT 50% SPHAGNUM MOSS WITH SEDGES AND SCATTERED DWARF SALIX SP . REST, SEDGE MEADOW, FLOODED IN SPRING. SCATTERED LOGS. ZAPUS PRINCEPS ALSO OBSERVED. Land owner/manager: KOOTENAI NATIONAL FOREST, THREE RIVERS RANGER DISTRICT Comments : Information source: Reichel, J.D. and S.G. Beckstrom. 1993. Northern bog lemming survey: 1992. [Unpublished report] Montana Natural Heritage Program. Helena, MT. 59620. Specimens : REICHEL, J.D. (3165 and 3166; 1992. 34 SYNAPTOMYS BOREAL IS ^003 NORTHERN BOG LEMMING Global rank; State rank: G5 Forest Service status : S2 Federal Status SENSITIVE Survey site name: EO rank: EO rank comments: MAYBEE MEADOWS A QUALITY EXCELLENT; LARGE SIZE; HABITAT PATCHES UP AND DOWNSTREAM. County: BEAVERHEAD USGS quadrangle : BIG HOLE BATTLEFIELD Township: Range: Section: TRS comments OOIS 017W 26 NW4SW4 Survey date: 1992-07-15 Elevation First observation: 1992-07-15 Slope/aspect Last observation: 1992-07-15 Size (acres) 6520 LEVEL 30 Location: ANACONDA RANGE; FROM WISDOM TAKE HWY 43 W. 13 MI. TO FS RD 1203; TURN RIGHT AND GO N . --7 MI . Element occurrence data: 4 TRAPPED, INCLUDING 3 AD. (SCROTAL) M. AND 1 F . W/ 3 EMBRYOS. General site description: MEADOW AREA SURROUNDED BY LODGEPOLE PINE. UPPER MEADOW WET W/ SPHAGNUM MOSS MATS, SALIX PLANIFOLIA, BOG BIRCH AND CAREX UTRICULARIA. LOWER MEADOW W/ SEDGES, SALIX DRUMMONDIANA, AND MUCH DRYER; LOWER MEADOW BADLY OVERGRAZED BY CATTLE . SHRUBS IN BOG AREA HEAVILY GRAZED BY DEER/ELK IN WINTER. Land owner/manager: BEAVERHEAD NATIONAL FOREST, WISDOM RANGER DISTRICT Comments : Information source: Reichel, J.D. and S.G. Beckstrom. 1993. Northern bog lemming survey: 1992. [Unpublished report] Montana Natural Heritage Program. Helena, MT. 59620. Specimens : BECKSTROM, S. (9-12). 1992 35 SYNAPTOMYS BOREAL IS ^004 NORTHERN BOG LEMMING Global rank; State rank: G5 Forest Service status : S2 Federal Status SENSITIVE Survey site name: EO rank: EO rank comments: MEADOW CREEK County: RAVALLI USGS quadrangle : SCHULTZ SADDLE Township: Range; OOIN 018W Section: TRS comments 10 S2NE4 Survey date: 1992-07-18 Elevation First observation: 1992-07-18 Slope/aspect Last observation: 1992-07-18 Size (acres) 5920 LEVEL 10 Location: ANACONDA RANGE; FROM SULA GO E . 12 MI . ON FS RD 101 TO FS RD 725; TURN RIGHT AND GO S . 6 MI . TO SITE. Element occurrence data: General site description: BOG AREA SURROUNDED BY SEDGES AND TALL SALIX SPP . CREEK RUNS ALONG WEST EDGE, BEAVER PONDS ON NORTH, ROAD TO THE EAST. SPHAGNUM MAT --10 ACRES . Land owner/manager: BITTERROOT NATIONAL FOREST, SULA RANGER DISTRICT Comments : Information source: Reichel, J.D. and S.G. Beckstrom. 1993. Northern bog lemming survey: 1992. [Unpublished report] Montana Natural Heritage Program. Helena, MT. 59620. Specimens : BECKSTROM, S. (13). 1992. 36 SYNAPTOMYS BOREAL IS ^005 NORTHERN BOG LEMMING Global rank: G5 State rank: S2 Forest Service status : Federal Status SENSITIVE Survey site name: EO rank: EO rank comments: BOWEN CREEK FEN A QUALITY EXCELLENT; LARGE SIZE; HABITAT PATCHES UPSTREAM. County: LINCOLN USGS quadrangle : DUNSIRE POINT Township: Range: Section: 031N 026W 1 TRS comments SW4NW4 Survey date: 1992-08-19 Elevation First observation: 1992-08-19 Slope/aspect Last observation: 1992-08-19 Size (acres) 4760 LEVEL 20 Location: SALISH MOUNTAINS; FROM WHITEFISH TAKE HWY 93 NW 17 MI TURN LEFT AND GO W --19 MI TO SITE. TO FS RD 60; Element occurrence data: TRAPPED 1 MALE; LITTLE SIGN. General site description: LARGE WET SPHAGNUM BOG SURROUNDED BY SUBALPINE FIR AND LODGEPOLE PINE. CAREX DOMINANT ON SPHAGNUM. MAJOR SHRUBS ARE DWARF SALIX AND BOG BIRCH. Land owner/manager: FLATHEAD NATIONAL FOREST, TALLY LAKE RANGER DISTRICT Comments : Information source: Reichel, J.D. and S.G. Beckstrom. 1993. Northern bog lemming survey: 1992. [Unpublished report] Montana Natural Heritage Program. Helena, MT. 59620. Specimens : 37 SYNAPTOMYS BOREAL IS ^00 6 NORTHERN BOG LEMMING Global rank; State rank: G5 Forest Service status : S2 Federal Status SENSITIVE Survey site name: EO rank: EO rank comments: SUNDAY CREEK B QUALITY GOOD; HABITAT PATCHES DOWNSTREAM. County: LINCOLN USGS quadrangle : SUNDAY MOUNTAIN Township: Range; 032N 026W Section: TRS comments 13 SE4NW4 Survey date: 1992-07-07 Elevation First observation: 1992-07-05 Slope/aspect Last observation: 1992-08-20 Size (acres) 4800 LEVEL 4 Location: SALISH MOUNTAINS; FROM STRYKER TAKE FS RD 315 SW --15 MI. TO CREEK CROSSING JUST PAST FS RD 3520 INTERSECTION. Element occurrence data: 8 TRAPPED INCLUDING SCROTAL AND JUVENILE MALES. SOME SIGN (RUNWAYS, CUTTINGS) . General site description: MEADOW ALONG CREEK IN SUBALPINE FIR FOREST W/ ABANDONED BEAVER DAMS AND PONDS. SALIX DRUMMONDIANA AND CAREX NEAR WATER'S EDGE. SLIGHTLY HIGHER IS SPHAGNUM W/ BOG BIRCH GRADING INTO FOREST. Land owner/manager: KOOTENAI NATIONAL FOREST, FORTINE RANGER DISTRICT Comments : Information source: Reichel, J.D. and S.G. Beckstrom. 1993. Northern bog lemming survey: 1992. [Unpublished report] Montana Natural Heritage Program. Helena^ MT. 59620. Specimens : BECKSTROM, S. (4-8) 1992. REICHEL, J. (3164). 1992 38 Appendix C . Maps of Northern Bog Lemming Sites 39 USGS Northwest Peak (7.5') Synaptomys borealis Hawkins Pond (002) 40 USGS Big Hole Battlefield (7.5') Synaptomys borealis Maybee Meadows (003) 41 USGS SchuLtz Saddle (7.5') Synaptomys borfialis Meadow Creek (004) 42 27'30' USGS Dunsire Point (7.5*) Synaptomys borealis Bowen Creek (005) 43 USGS Sunday Mountain (7.5') Synaptomys borealis Sunday Creek (006) 44 Appendix D . Botanical Community Surveys 45