The tracking survey will provide information regarding other
species that interact with lynx. Competition with other mammalian
carnivores may have a negative impact on lynx (Buskirk 2000).
Snow tracking efforts following statistically sound protocols
(Squires 2002, Vashon et al. 2003) will be used to determine
the relative density of several mammal species. Primary species
of interest include lynx prey species (snowshoe hare and red
squirrel) and mammalian mesocarnivores that may compete with
lynx (bobcat, marten, fisher, red fox, coyote, wolf). Densities
and distributions of other mesocarnivores will be compared
with recent and historical records from track counts conducted
by MNDNR (Fig. 3). We will determine the relative abundance
and distribution of competing species and their spatial distribution
with respect to lynx, prey abundance, and vegetation.
|Figure 3. Fisher and bobcat winter track indices in Minnesota from 1991 to 2002. Data from an unpublished report by J. Erb, MNDNR.|
“Reconnaisance” routes will be used to estimate mesocarnivore and prey species distribution and relative abundance following established protocol (Squires 2002). This technique has been tested with lynx, and approximately 2/3 of track crossings were observed by the snowmobile operator (Vashon et al. 2003). Although sample size was small, we should be able to carry out additional testing of the probability of detection of lynx tracks with animals collared in the Minnesota study. We will use a survey intensity of between 80 and 100 km of trails per 100 km2, following the findings of Vashon et al. (Vashon et al. 2003), where through simulation found that sampling intensities at that level resulted in lynx track detection the same as at a survey intensity of 131 km of trails per 100 km2.
Particular focus will be placed on investigating the competitive interactions between lynx and other mesocarnivores that may be facilitated by the compaction of snow that occurs with such human activities as snowmobiling and cross-country skiing. The relative abundance data of mesocarnivores and wolves will be analyzed in relation to the landscape-scale composition of forest-types in the SNF. Some wolf density and distribution data over the past 30 years will be available from the research project of L.D. Mech, one of the investigators of this project. Compositional analysis (Aebischer et al., 1993) or similar distance-based classification schemes (Conner et al., 2003) will be used in the analysis.