Snowtrack surveys for Canada lynx presence in Minnesota west of Highway 53

Transcription

1 Snowtrack surveys for Canada lynx presence in Minnesota west of Highway Annual Report to Minnesota Department of Natural Resources Ronald Moen, Ph.D. Gerald Niemi, Ph.D. Julie Palakovich Christopher L. Burdett Center for Water and Environment Natural Resources Research Institute University of Minnesota 5013 Miller Trunk Highway Duluth, MN NRRI Technical Report No. NRRI/TR This report can be cited in its current form Please contact us at NRRI for updates and additional publications on this topic

2 Summary Historical and recent Canada lynx sighting reports have been concentrated in northeastern Minnesota, with scattered reports from other parts of the state. Lynx that have been radiocollared since 2003 have also remained in northeastern Minnesota and adjacent parts of Ontario. Yet there are credible reports from other parts of Minnesota, and historically lynx sightings have been reported from throughout the state. Recent sighting reports outside of northeastern Minnesota could represent transient animals moving through an area or could be resident lynx. If lynx are resident in an area, snow track surveys can be used to search for evidence of lynx to confirm continued presence. Because the number of searches is limited by weather and logistics, we prioritized sites to survey using data from the Canada lynx sightings database maintained by the Minnesota DNR. Criteria used from the sightings database were proximity of sighting reports to each other, sightings repeated in the same place in subsequent years, and sighting report quality. Secondarily, we evaluated habitat characteristics in priority sites compared to habitat characteristics in the home ranges of radiocollared lynx. First, we compared landscape level characteristics within Canada lynx home ranges to the same landscape level characteristics in random points outside of radiocollared Canada lynx home ranges to identify characteristics of lynx home ranges that might be present where sightings have been reported. Of the criteria checked only percent of area that showed evidence of being harvested in ca aerial photos was significantly different between random points inside and outside of home ranges of radiocollared lynx. We compared area harvested in locations of sighting reports to area harvested inside of lynx home ranges. When snow conditions were suitable we searched the highest priority sites outside of the core area of lynx presence in northeastern Minnesota for lynx sign. No tracks were found during 3 surveys, nor were lynx tracks located in independently conducted track surveys following a different methodology near 2 priority sites in Cass and Beltrami counties. Absence is not confirmed if lynx tracks are not found, but it does provide support for the hypothesis that lynx are not permanent residents in areas where sightings reports have been received. Lynx tracks were found in 2 track surveys conducted in areas where lynx were known to be present when the survey protocol was used. This suggests that resident lynx are not currently present at locations of priority sightings reports in 2006, but does not exclude the possibility that lynx are present in adjacent areas. ii

3 Table of Contents Summary... ii Table of Contents... iii List of Figures... iii List of Tables... iii List of Appendices... iii Introduction...1 Methods...3 Results...6 Discussion...12 References Cited...15 List of Figures Figure 1. Historical distribution of Canada lynx sightings in the upper midwestern United States....1 Figure 2. Minnesota lynx sighting reports from database maintained by the Minnesota D.N.R...2 Figure 3. Example screenshot from ArcView showing 1 km radius buffer around sighting report...4 Figure 4. Clustering of lynx sightings reports within 10 km of each other....6 Figure 5. Percent of area harvested within a 1 km radius of each sightings report...8 Figure 6. Selection of potential track survey sites based on clustering and cover type interpretations Figure 7. Example snow track surveys in Aitkin and south Lake Counties...11 Figure 8. Snow track survey in Aitkin County in winter Figure 9. Area of interest for Beltrami County snow track survey against 2003 aerial photograph...17 Figure 10. Snow track survey in Itasca County in winter Figure 11. Area of interest for Koochiching County snow track survey against 2003 aerial photograph Figure 12. Area of interest for Carlton County snow track survey against 2003 aerial photograph Figure 13. Snow track survey in west St. Louis County in winter Figure 14. Area of interest for Cass County snow track survey against 2003 aerial photograph Figure 15. Area of interest for Lake of the Woods County snow track survey against 2003 aerial photograph Figure 16. Snow track survey in south Lake County in winter Figure 17. Snow track survey in north Lake County in winter Figure 18. Snow track survey in Cook County in winter List of Tables Table 1. Characteristics of habitat within and outside of lynx home ranges....5 Table 2. t-test results for comparison of habitat characteristics...7 Table 3. Track survey sites identified based on the sightings database and habitat characteristics....9 Table 4. Completed track survey sites identified based on the sightings database and habitat characteristics...10 List of Appendices Appendix 1. Map data and narrative for Aitkin County snow track survey Appendix 2. Planned location for Beltrami County snow track survey...17 Appendix 3. Map data and narrative for Itasca County snow track survey Appendix 4. Planned location for Koochiching County snow track survey Appendix 5. Planned location for Carlton County snow track survey...20 Appendix 6. Map data and narrative for west St. Louis County snow track survey...21 Appendix 7. Planned location for Cass County snow track survey Appendix 8. Planned location for Lake of the Woods County snow track survey Appendix 9. Map data and narrative for south Lake County snow track survey...24 Appendix 10. Map data and narrative for north Lake County snow track survey Appendix 11. Map data and narrative for Cook County snow track survey...26 iii

4 Introduction The Canada lynx (Lynx canadensis) is a felid found in the boreal forest, always in association with its primary prey species, the snowshoe hare (Lepus americanus). Historical reports (Fig. 1), current sightings reports (Fig. 2), and radiotelemetry locations are concentrated primarily north and east of Duluth (DOI 2000, Moen at el. 2006). This core area of presence was recognized in the recent proposal for designation of Critical Habitat for Canada lynx, which identified U.S. Highway 53 as the western boundary (DOI 2005b). Figure 1. Historical distribution of Canada lynx sightings in the upper midwestern United States (McKelvey et al. 2000). Most sightings in Minnesota are concentrated in the north and east of Duluth (shaded red on the map). Transient animals may be the source of sightings reports from other parts of Minnesota, and adjacent states, which are often associated with a year of high harvest in Ontario and Manitoba. Recent sighting reports for lynx include many from areas outside of Northeastern Minnesota (Fig. 2), some of which appear to be clustered in specific areas. Some of these reports have been verified by DNA analysis, and at least one report indicated that kittens were present with an adult female. Cumulatively, even though few of these reports have been verified genetically, the reports suggest that lynx have been at least occasionally present outside of the core area in northeastern Minnesota over the past 5 years. One possibility is that these reports are of transient animals. An alternative possibility is 1

5 that the recent sightings may be of resident lynx in a population that is expanding to the west and south of the core area in northeastern Minnesota. If they are resident animals, we would expect continued presence and predict that tracks would be found in the snow in winter in the area surrounding the sighting report location. In this report we describe how we prioritized specific areas to survey in 2006, summarize a technique to quickly compare habitat characteristics inside and outside of lynx home ranges, and describe the results of snow-track surveys. Figure 2. Sightings reports coded based on date of sighting and level of verification. At this scale there appear to be clusters of sightings outside of the core area of Cook, Lake, and St. Louis counties. Source data is the Canada lynx sightings database maintained by the Minnesota D.N.R (MN DNR 2006) with reports received through 1/23/

6 Methods Analysis of Sightings Database. The sightings database is maintained by the Minnesota DNR, and is the repository of all sightings of Canada lynx in Minnesota that have been forwarded to the Minnesota Natural Heritage and Nongame Research Program by DNR personnel or other partner agencies. We used the 366 records that were entered in the database as of 23 January Each point in the database is stored with UTM coordinates and date. We also used the county and level of verification attributes in the database. The county attribute was used to exclude locations from Cook, St. Louis, and Lake Counties, a decision made during a conference call in which representatives of the Minnesota Department of Natural Resources (MN DNR), the U.S. Forest Service (USFS), the Fish and Wildlife Service (FWS), the National Park Service (NPS), and NRRI participated. There were 286 sightings reports in the three excluded counties, leaving 80 points to be considered as potential locations to search for lynx. Each point in the Sightings Database was buffered to 3, 10, and 20 km with ArcView to determine how many other sightings reports were clustered within that distance. A second criteria was to score the locations based on the level of verification that had been possible, with highest weighting given to verification with reproduction, second highest to verified, and lowest to unverified sightings reports. For this initial work we used terminology for verification on the DNR website, meaning that DNA/Professional verification was not required for a sighting to be considered verified. If DNA verification is obtained on lynx, it often means that the animal is dead and tissue was collected. Characteristics of lynx home ranges. The intent of this procedure was to devise a rapid procedure to quantify potentially important characteristics of lynx home ranges, and then use this procedure at every lynx sighting report. To do this, we used ArcView and selected locations inside and outside of home ranges for a visual interpretation of several habitat characteristics. Next, we used ArcView to visually interpret the same habitat characteristics at each of the lynx sighting reports to determine if characteristics were similar to those found in lynx home ranges. 3

7 Figure 3. Example screenshot from ArcView showing the 1 km radius buffer around the sighting report in Aitkin County that was evaluated for habitat characteristics Home ranges of radiocollared lynx were calculated with the Animal Movement Analyst extension for ArcView (Burdett et al. in press). We used 95% kernel home ranges and merged home ranges of all GPS radiocollared lynx into a single coverage. We buffered 30 random points with a 1 km radius within the merged 95% home ranges. The same spatial configuration of random points was offset 20 km to the west and used to sample the cover type in an area not occupied by lynx. An alternative approach which we will use in the future would be to create the points to sample outside of lynx home ranges randomly. The buffered circle of 1 km radius around each point was visually examined on a ca aerial photo to estimate values for several habitat characteristics for each random point (Table 1). The 30 random points within lynx home ranges, the 30 random points outside of lynx home ranges, and the sightings database points outside of Cook, Lake, and St. Louis counties were all viewed by the same observer over a 3-day time span. Results were entered directly into an Excel spreadsheet. Numeric measurements were compared with a t-test between points inside and outside of lynx home range to identify what characteristics should be examined in the area around each point in the sightings database. 4

8 Table 1. Characteristics of habitat that were recorded from aerial photographs for random points within and outside of lynx home ranges. Field Units Comments Primary Road km Length of primary road (vehicular travel) measured with ArcView Ruler Secondary Road or Trail km Length of trails visible in the aerial photo measured with ArcView Ruler Linear Water Feature Presence or absence of a river or stream Cut areas % Percent of the 1 km radius circle in land cut before These areas would be years old in Bogs % Percent of the 1 km radius circle in bog-type vegetation Agricultural land % Percent of the 1 km radius circle in agricultural fields. This category was added for the points from the sightings database because many sightings reports were associated with agricultural land. Water Presence or absence of standing water (lake, pond) Snow Track Surveys Locations to survey were prioritized based on number and pattern of sightings in an area. Landscape characteristics at survey sights were also compared to characteristics inside of lynx home ranges. Priority locations were surveyed when snow conditions were suitable following established protocols to the extent possible (Vashon et al. 2003, Moen et al. 2004). Snow track surveys are conducted from snowmobile or truck moving at speeds < 20 km / hr within hours of a snowfall. If blowing and drifting had occurred, this was considered equivalent to a snowfall. We also conducted 2 snow track surveys following the same protocol in locations where radiocollared lynx were present to test the effect of road density. Chris Burdett, Dave Danielsen, and Dave Grosshuech conducted the surveys. 5

9 Results There were 80 sightings reports outside of Lake, Cook, and St. Louis counties in the analysis. First we summarize clustering of locations, then we identify the habitat attributes which may be useful, and indicate which locations are identified as priority locations to conduct snow track surveys on. In the final section we provide results of the 6 surveys conducted in Clusters of sightings reports. Clustering sightings reports identified potential locations, but it was also apparent that sightings reports outside of Lake, Cook, and St. Louis counties have not been consistently close to each other (e.g., compared to sightings reports in the core area). Most sightings were not located within 3 km of another sightings report. There were only 2 pairs of sightings that were within 3 km of each other, one pair in Lake of the Woods County and one pair in Itasca County. Expanding the cluster radius to 10 km resulted in including 46 of the 80 sightings reports in at least one cluster from many counties in northern Minnesota (Fig. 4). An alternative way to view this would be that 33 of the sightings reports were at least 10 km from any other sighting. When the cluster radius was increased to 20 km 58 of the 80 reported sightings were near another sightings report. Figure 4. Clustering of sightings reports within 10 km of each other. For each sighting outside of the core area there were 0, 1, or 2 other sightings reports within 10 km. For this figure, green symbols are better then yellow symbols which are better then the isolated red symbols. Sightings reports from the core area of Cook, Lake, and St. Louis counties are shown as blue symbols. 6

10 Habitat characteristics. Of the habitat characteristics examined inside and outside of lynx 95% kernel home ranges, only the percentage of area that had been recently cut in ca. 15 year old photographs was different (Table 2). There was more area cut inside of known lynx home ranges than outside. We believe that these results would be qualitatively similar if sample size were increased or if an alternate sampling strategy were employed, but this result should be considered preliminary and subject to some refinement. For example, it would be useful to determine the percent of cut area in 50% kernel home ranges compared to the random plot, as well as the 95% kernel home range. However, the results with the 95% kernel home range are probably conservative with respect to cover type characteristics that lynx might use, and they do suggest that we can use the cut area surrounding sightings reports as an indicator of habitat quality, and thus as a criteria for determining where snow track surveys should be conducted. Table 2. t-test results for comparison of habitat characteristics from 50 points inside of Canada lynx 95% kernel home ranges to 50 random points outside of home ranges. Characteristic Inside Outside t p Cut area (%) 22 (2.1) 16 (1.8) Bog area (%) 19 (1.7) 15 (2.1) Primary Road (km / 3.14 km 2 ) 1.60 (0.22) 1.61 (0.18) Secondary Road or Trail (km / 3.14 km 2 ) 2.02 (0.23) 1.77 (0.16) The historical cut area should be related to lynx presence because snowshoe hare, the main prey of lynx, are found in younger forests (Aubry et al. 2000). We estimated the percentage of cut area within a 1 km radius of the location of each sighting report (Fig. 5), and compared it to the percentage of cut area in known lynx home ranges (Table 2). Even though the difference was not large (22% vs. 16% harvested area inside and outside of lynx home ranges), it was significant. Twelve of the 80 (15%) sighting report locations were in areas with cut area percentages similar to or higher than that found in known lynx home ranges. 7

11 Figure 5. Percent of area harvested within a 1 km radius of each sightings report estimated from ca aerial photography. Green symbols are better then yellow symbols, and the pink symbols had very little harvested area present in Sightings reports from Cook, Lake, and St. Louis counties are shown as blue symbols. Identification of Survey Sites. The general sites were identified based on the analysis of clusters and the cover type analysis are in different counties (Fig. 6, Table 3). Three other survey site locations were identified in St. Louis and Lake Counties. Two of these locations were within known lynx home ranges, and the other two were located where lynx sightings have been reported over the past few years, and presence in past years has been confirmed by genetic testing. Aerial photographs of the surrounding area were examined before identifying the location to conduct the track survey on. 8

12 Figure 6. Selection of potential track survey sites based on clustering and cover type interpretations. The numbers are identified in Table 3. Table 3. Track survey sites identified based on the sightings database and habitat characteristics. The ID number does not indicate priority order among the group of 8 sightings. The Records column indicates which records in the MN DNR database are associated with a location. ID County Records Comments. 1 Aitkin 3 Female lynx with kittens observed in October Beltrami 9, 10, 11 NW corner of Chippewa National Forest. No lynx tracks were found in over 220 km (130 miles) of track surveys conducted in 2 townships 70 km (40 miles) west of this site and 100 km (60 miles) northeast of the Cass County site (ID 7 below) by Chippewa National Forest Personnel (Jim Gallagher and Jeff Jerry, pers. comm.). 3 Itasca 144, Cluster of 3 locations, although only 1 verified. 4 Koochiching 161, 163 Near Voyageurs National Park, will be searched in 2007 as part of a new project in that area. 5 Carlton 13, 17 Have had non-reported sightings passed on about this area. Little area cut in 1990 photographs, but satellite imagery and 2003 photos indicate harvest since St. Louis 309, 356, 357, 360 Western St. Louis County near Itasca County border. 4 sightings and one unverified report of possible kittens not included. 7 Cass 24, 28 SW corner of Chippewa National Forest. See ID 2 (Beltrami 8 Lake of the Woods County) above for additional comments. 267, 268 Older sighting but clustered. 9

13 Track Surveys Completed Three track surveys were completed in Aitkin, Itasca, and western St. Louis County in winter 2006 (Table 4). No lynx tracks were found outside of the core area in northeastern Minnesota in about 400 km of linear survey routes. Lynx tracks were found in track surveys conducted in known lynx home ranges in Lake County with about 30 km of linear survey routes. These surveys in known lynx home ranges served as controls for the experimental technique. Lynx tracks were not found in an area of Cook County near Tofte with recent sightings reports but no radiocollared lynx in 90 km of linear survey routes. Weather conditions (not enough snow, or blowing snow) made it impossible to conduct more track surveys in winter Track surveys were conducted within hours of snowfall when blowing snow has not occurred. Table 4. Completed track survey sites identified based on the sightings database and habitat characteristics. ID County Km Km 2 Km / 100 km 2 Lynx tracks? 1 Aitkin No 2 Beltrami No 3 Itasca No 6 St. Louis - W No 7 Cass No C-1 Lake - S Yes C-2 Lake - N Yes C-3 Cook No 10

14 Figure 7. Example snow track surveys. Area surveyed in Aitkin County for lynx tracks (top) and area surveyed in Cook County (bottom). Red dots indicate the track followed in either snowmobile or car. The border area is about 500 m from the extent of the linear survey route and is rectangular. Sightings locations are also included on the map. The yellow dot with black circle represents locations where lynx tracks were found. N W E S Sighting S Dnr_lynx_date.dbf Dnr_lynx.dbf S Verified-Reproduction Verified Unverified Miles Kilometers N W E S Sighting Dnr_lynx_date.dbf S Dnr_lynx.dbf S Verified-Reproduction Verified Unverified S S S S S Miles Kilometers South Lake County Track RM -- 8/11/06 11

15 Discussion Sighting reports are more common in northeastern Minnesota, which we would expect based on historical records. The motivation behind these snow track surveys was to determine whether we could find evidence of lynx in areas where there have been recent sightings of lynx outside of the core area in northeastern Minnesota. No lynx tracks were found during track surveys of 3 locations. This provides support for the hypothesis that lynx seen were transients, or are no longer residents in these 3 areas in Aitkin, Itasca, and west St. Louis counties. One requirement for the success of the snow track survey protocol is that lynx must cross a road or snowmobile trail within 1 to 3 days after a snowfall. Radiocollared lynx in northeastern Minnesota appear to meet this requirement, as do lynx in other areas with resident lynx (Vashon et al. 2002, Squires et al. 2004). Lynx behavior as given in many of the sighting report narratives also support use of roads (or brushy areas adjacent to roads) as travel corridors. This suggests that if lynx are resident in an area, they would be visible and seen more than once, as has been the case for the radiocollared lynx in the telemetry project. Based on GPS collar locations, several of the radiocollared lynx have crossed roads on a consistent basis 2-3 or even more times a week. Even though we know that lynx crossed roads based on GPS locations, we still have had relatively few sightings reports from the general public of these animals, and we have also had relatively few sightings while project personnel are in the field. A second assumption the snow track surveys tested was that lynx remained in an area after the initial sighting reports, which in effect means that resident animals were sighted. This was the rationale for using clusters of sightings to prioritize search locations, because if lynx were resident in an area we would expect persistent presence and repeat sightings. This is also supported by telemetry data from lynx in Minnesota (Moen et al. 2006). For all of the females with kittens that we have monitored with radiocollars, movements during the summer are usually less than 10 miles 2, with summer/fall kernel home ranges of 21±7 km 2, (mean ± SE) and a range of km 2 and denning kernel home ranges of 6±1 km 2, with a range of 5 to 8 km 2 (Burdett et al. in press). Kittens surviving into their first winter that were radiocollared also had relatively limited movements until the age of 21 months, and stayed near the area where they were born. Mortality within the mother s home range has been documented for some of these offspring, others have moved up to 30 miles away from the natal area. For the snow track survey, the most important aspect may be the site fidelity of females with kittens to an area for months after parturition. If this is generalizable to lynx outside of the core area in what may be more marginal habitats, we would expect females with kittens to remain in an area for extended periods of time. 12

16 Even radiocollared lynx without kittens that have been followed for months often have established locations that are visited (Moen et al. 2006). Males are more likely to make what have been termed extra-territorial movements, and we have documented movements of 40 to 80 miles generally in a north-south direction for almost all adult males that we would classify as residents. However, these animals have all exhibited some degree of site fidelity and we would again expect repeat visits and repeat sightings in areas with resident lynx outside of the core area in northeastern Minnesota. In a couple cases we have radiocollared individuals that did not remain in the area where they were captured (Moen et al. 2006). One possibility is that these lynx were scared away by the handling process, but this is not supported by response of other lynx to handling. Several lynx on the project have been handled multiple times, and still remained in the same area. This includes at least one male who was initially captured while on one of his extra-territorial movements. Even though we have documented tracks in an area before capturing and radiocollaring an animal, the animal is not necessarily a permanent resident of an area. This provides additional support for the possibility that lynx seen outside of northeastern Minnesota may not be resident animals. Even if we do not find lynx tracks in a survey, it is impossible to prove absence from an area. Surveys can detect presence, and one can be more confident in finding all lynx tracks if it is possible to survey a longer track route in the same area. All radiocollared lynx were detected in Maine if 80 km / 100 km 2 was surveyed for track crossings (Vashon et al. 2003). When the survey intensity went down to 55 km / 100 km 2 lynx or less presence was still detected, even though not all lynx tracks were observed. Road and snowmobile trail densities in the areas surveyed in Minnesota are not high enough to reach the threshold of 80 km road / 100 km 2 area. There may be regional differences in the threshold, however, as both surveys that we conducted in areas with radiocollared lynx found snow tracks when the same survey protocol was used with a lower road density. Repeat visits to an area have been suggested as helpful in detecting lynx presence in Wyoming (Squires et al. 2004), but are logistically difficult to complete. The repeat visits were also suggested when transects were only 8 km long, while the approach used in these surveys was to survey for a longer distance (ca. 100 km if possible), which would effectively increase the transect density to about the low level in the protocol used in Maine. An alternative approach might be to wait to conduct a survey as long as possible after a snowfall, rather than restricting to survey to a 24 to 72 hour post-snowfall window. Waiting longer would allow lynx to leave tracks in more of the area in which they are resident, especially if the goal is simply to document presence in an area. 13

17 Priority sites for the snow track surveys were based primarily on the nearness of other sighting reports, the level of verification, and the time sequence of reports. The importance of area in younger forests demonstrated by the higher presence in 15 to 25 year old cuts in the home ranges of radiocollared lynx was an indicator that sightings are occurring in areas that lynx would consider good habitat. Some additional areas may have been cut after the aerial photographs were taken in the early 1990 s, and those areas may be providing additional habitat for snowshoe hares, which would likely increase the quality of the habitat for lynx. It would be possible to identify more rigorous quantitative criteria for identifying priority sites, such as assigning points for proximity of other sightings, verification level, presence of kittens in sighting, etc. However, given the nature of the data collection and analysis procedure, we believe the best approach is to identify locations with the highest apparent probability of success, and then conduct snow track surveys among these sites based on logistics, access, and other considerations. Additional sites will be surveyed in the winter. It may be necessary to reprioritize sites based on new sighting reports that are added to the MN DNR database. However, we have not received consistent Canada lynx sightings reports from any area outside of northeastern Minnesota. 14

18 References Cited Aubry, K. B., G. M. Koehler, and J. R. Squires Ecology of Canada lynx in southern boreal forests. Pages in L.F. Ruggiero, K. B. Aubry, S. W. Buskirk, G. M. Koehler, C. J. Krebs, K. S. McKelvey and J. R. Squires, editors. Ecology and conservation of lynx in the United States. University Press of Colorado, Denver, CO. Department of the Interior Endangered and threatened wildlife and plants; determination of threatened status for the contiguous U.S. distinct population segment of the Canada lynx and related rule; final rule. Federal Register 65(58). Department of the Interior. 2005a. Endangered and Threatened Wildlife and Plants; Proposed Designation of Critical Habitat for the Contiguous United States Distinct Population Segment of the Canada Lynx Federal Register 70 (216). Burdett, C., Moen, R., Niemi, G.J., and L.D. Mech. In press. Defining Canada lynx space use and movements with GPS telemetry. Journal of Mammalogy. MN DNR Page contents as of 1/23/2006. McKelvey, K. S., K.B. Aubry, and Y. K. Ortega History and distribution of lynx in the contiguous United States. Pages in lf Ruggiero, K. B. Aubry, S. W. Buskirk, G. M. Koehler, C. J. Krebs, K. S. McKelvey and J. R. Squires, editors. Ecology and conservation of lynx in the United States. University Press of Colorado, Denver, CO. Moen, R., C. Burdett, G.J. Niemi, and L.D. Mech. 2004b. Canada Lynx in the Great Lakes Region Annual Report to USDA Forest Service and MN Cooperative Fish and Wildlife Research Unit. NRRI Technical Report No. NRRI/TR Squires J.R., K.S. McKelvey, and L.F. Ruggiero A snow-tracking protocol used to delineate local lynx, Lynx canadensis, distributions. Canadian Field-Naturalist 118: Vashon, J., A. Vashon, and S. Crowley Partnership for lynx conservation in Maine, Dec Dec field report. Unpublished Report, Maine Dept. Inland Fish and Wildlife. 15

19 Appendix 1. Map data and narrative for Aitkin County snow track survey. This survey was conducted 2/23/2006 by Chris Burdett and Dave Grosshuech 24 hours after the last snowfall. Very little consistent hare sign was in the survey area, < 10 hare tracks were seen all day. Wolf and deer tracks were abundant. Habitat was not consistent with that occurring in lynx activity areas in Arrowhead region. Most stands were dominated by hardwoods or wet lowland conifers (spruce/tamarack). Most consistent hare sign was seen east of the reported lynx sighting. Figure 8. Snow track survey in Aitkin County in winter Red dots indicate the track followed in either snowmobile or car. The border area is about 500 m from the extent of the linear survey route and is rectangular. Sightings locations are also included on the map. No lynx tracks were found. N W E S Sighting S Dnr_lynx_date.dbf Dnr_lynx.dbf S Verified-Reproduction Verified Unverified Miles Kilometers Aitken Cty Track RM -- 7/11/06 16

20 Appendix 2. Planned location for Beltrami County snow track survey. The symbols represent locations of reports in Beltrami County in the Lynx sightings database. This snow track survey was not completed in winter Figure 9. Area of interest for Beltrami County snow track survey against 2003 aerial photograph. Location of lynx sighting report is indicated by colored stars. 17

21 Appendix 3. Map data and narrative for Itasca County snow track survey. This survey was conducted 2/11/2006 by Chris Burdett and Dave Grosshuech about 24 hours after a snowfall. Patches with consistent hare sign were fairly widely dispersed in survey area. Largest contiguous areas with hare tracks were along County Road 52, especially on Grant-In-Aid snowmobile trail near Little Bear Lake, and along a current logging road south of MN 1. Most hare sign along CR 52 was south of the road. The CR 52 area had a considerable amount of coniferous forest types including some young pine plantations. The area south of MN 1 had a fairly large stand of young red pine interspersed with lowland conifer stands and numerous clearcuts. The red pine stand in this area was less than 15 years of age. Tracking conditions were average during the survey as about 1 of fresh snow fell during survey. Snowmobile routes were less affected due to forest cover with all tracks investigated on snowmobile routes allowing species ID if followed under forest cover. Tracks found include deer (common), snowshoe hares (locally abundant), squirrel (< 10 tracks), wolf (> 5 tracks), fisher (< 3 tracks), and marten (< 2 tracks). Figure 10. Snow track survey in Itasca County in winter Red dots indicate the track followed in either snowmobile or car. The border area is about 500 m from the extent of the linear survey route and is rectangular. Sightings locations are also included on the map. No lynx tracks were found. N W E S Sighting Dnr_lynx_date.dbf Dnr_lynx.dbf S Verified-Reproduction Verified Unverified Miles Kilometers Itasca Cty Track RM -- 7/11/06 18

22 Appendix 4. Planned location for Koochiching County snow track survey. The symbols represent locations of reports in Koochiching County in the Lynx sightings database. This snow track survey was not completed in winter 2006, but will be done in winter Figure 11. Area of interest for Koochiching County snow track survey against 2003 aerial photograph. Location of lynx sighting report is indicated by colored stars. 19

23 Appendix 5. Planned location for Carlton County snow track survey. The symbols represent locations of reports in Carlton County in the Lynx sightings database. This snow track survey was not completed in winter Figure 12. Area of interest for Carlton County snow track survey against 2003 aerial photograph. Location of lynx sighting report is indicated by colored stars. No 2003 photography is available for the center strip of this photograph where the lynx sighting was reported from. 20

24 Appendix 6. Map data and narrative for west St. Louis County snow track survey. This survey was conducted 3/7/2006 by Chris Burdett and Dave Grosshuech. The survey was done approximately 36 hours after a snowfall. No lynx tracks detected and no dense pockets of snowshoe hare activity found. On snowmobile routes, the most abundant hare sign was found E of Silica (SW of Sand Lake) on unnamed trail running E off of snowmobile trail. Habitat in this area of moderate hare density was consistent with dense hare areas in Arrowhead region younger conifer dominated mixed wood stands. A few fisher and fox tracks were seen in this area. Vehicle routes had more agricultural fields and open grassy/shrubby fen relative to lynx areas in Arrowhead. Human presence, either agriculture or residences, was also more prevalent than in Arrowhead lynx activity areas. Figure 13. Snow track survey in west St. Louis County in winter Red dots indicate the track followed in either snowmobile or car. The border area is about 500 m from the extent of the linear survey route and is rectangular. Sightings locations are also included on the map. No lynx tracks were found. N W E S Dnr_lynx_date.dbf Sighting Dnr_lynx.dbf S Verified-Reproduction Verified Unverified Miles Kilometers Itasca Cty Track RM -- 7/11/06 21

25 Appendix 7. Planned location for Cass County snow track survey. The symbols represent locations of reports in Cass County in the Lynx sightings database. This snow track survey was not completed in winter Figure 14. Area of interest for Cass County snow track survey against 2003 aerial photograph. Location of lynx sighting report is indicated by colored stars. 22

26 Appendix 8. Planned location for Lake of the Woods County snow track survey. The symbols represent locations of reports in Lake of the Woods County in the Lynx sightings database. This snow track survey was not completed in winter Figure 15. Area of interest for Lake of the Woods County snow track survey against 2003 aerial photograph. Location of lynx sighting report is indicated by colored stars. 23

27 Appendix 9. Map data and narrative for south Lake County snow track survey. This survey was conducted 1/12/2006 by Dave Danielsen and Dave Grosshuech about 36 hours after a snowfall. Five different sets of lynx tracks were observed throughout the survey area with one set of multiple tracks indicating a female with kittens. These tracks were found widely distributed across the survey area and represented the presence of multiple animals. No areas of dense hare activity were found, but hare sign was noted throughout the entire survey area. Areas of higher hare densities were found in Sullivan lake campground and on the south end of the Stony River road. Habitat in these areas of moderate hare densities were young regenerating conifer stands and alder swamps. Tracks of fisher (Martes pennanti), wolf (Canis lupus) and red fox (Vulpes vulpes) tracks were uncommon but were observed over the entire survey area. Figure 16. Snow track survey in south Lake County in winter Red dots indicate the track followed in either snowmobile or car. The border area is about 500 m from the extent of the linear survey route and is rectangular. Sightings locations are also included on the map. The yellow dot with black circle represents locations where lynx tracks were found. N W E S S Dnr_lynx_date.dbf Dnr_lynx.dbf S Sighting Verified-Reproduction Verified Unverified S S S S S S S Miles Kilometers Itasca Cty Track RM -- 7/11/06 24

28 Appendix 10. Map data and narrative for north Lake County snow track survey. This survey was conducted 1/21/2006 by Dave Danielsen and Dave Grosshuech about 48 hours after a snowfall. Four different sets of lynx tracks were found in the survey area. High densities of snowshoe hare activity were found on Forest Road 369A and on multiple areas of Highway 1. Snowshoe hare were present, but in lesser densities throughout the rest of survey area. Tracks of fisher (Martes pennanti) and wolf (Canis lupus) were common and widely distributed across the survey area. Figure 17. Snow track survey in north Lake County in winter Red dots indicate the track followed in either snowmobile or car. The border area is about 500 m from the extent of the linear survey route and is rectangular. Sightings locations are also included on the map. The yellow dot with black circle represents locations where lynx tracks were found. N W E S Sighting Dnr_lynx_date.dbf S S S S S Dnr_lynx.dbf S Verified-Reproduction Verified Unverified S Miles Kilometers Itasca Cty Track RM -- 7/11/06 25

29 Appendix 11. Map data and narrative for Cook County snow track survey. This survey was conducted 2/28/2006 by Dave Danielsen and Dave Grosshuech about 30 hours after a snowfall. No lynx tracks were found and no dense pockets of snowshoe hare activity found. The most abundant hare sign was found north of Wringer lake at the junction of Wringer Lake Road and Forest Road 350. Habitat in this area of moderate hare density was dense regenerating Jack Pine and Red Pine. Tracks of wolves (Canis lupus) were numerous and wide-spread across the survey area. While not as abundant, tracks of fisher (Martes pennanti) and red fox (Vulpes vulpes) were also noted throughout the entire survey area. Figure 18. Snow track survey in Cook County in winter Red dots indicate the track followed in either snowmobile or car. The border area is about 500 m from the extent of the linear survey route and is rectangular. Sightings locations are also included on the map. No lynx tracks were found. W N S E Dnr_lynx_date.dbf S Sighting S Dnr_lynx.dbf S Verified-Reproduction Verified Unverified Miles Kilometers Itasca Cty Track RM -- 7/11/06 26