Snowtracking and Backtracking
Snow tracking has long been used to develop indices of relative abundance for mammals (Pullianen 1980, Thompson, F. R.,III and Fritzell 1989, Linden et al. 1996, Kurkki et al. 1998). A track-based methodology would support and complement both telemetry and overall research efforts. We will use two distinct tracking methods: (1) snow-tracking performed across repeatable routes to obtain general information on mesocarnivore and prey species relative abundance, and (2) back-tracking lynx tracks in snow to non-invasively collect scats and hair. Back-tracking will be conducted within the general relative abundance track surveys following established protocols (Squires 2002).
The basic snow tracking protocol for lynx was developed by Dr. John Squires to investigate areas where lynx had been detected with hair snares following the National Lynx Survey protocol. The protocol is designed to find lynx after their presence has been detected. The tracking protocols we will follow use both the “intensive” and “reconnaisance” routes (Squires 2002). In addition, we will use the backtracking portion of the protocol to collect samples for DNA analysis.
Snow tracking can also provide insights into the general ecology and natural history of lynx. Kill and cache sites, inferred hunting behavior, scent marking behavior, and detailed movement data can all be collected while following lynx tracks in the snow. Lynx tracks will be detected using either the known locations of radio collared animals or tracks detected during snow track surveys (Squires 2002). Lynx trails will be either backtracked or foretracked if tracks are not deemed to be < 24 hrs old. While following tracks, handheld GPS units will be used to collect track logs depicting the detailed lynx movements. All daybeds, sits, and scentmarks will be entered onto the GPS units. By importing GPS data onto a GIS, detailed lynx movement and behavior patterns can be examined with regard to habitat features. The distance between successive daybeds representing a daily movement distance can easily be determined from the GIS data. Track logs on GPS units while following lynx trails will lead to additional habitat information. Track logs collected on GPS units will allow us to collect detailed geo-referenced movement and activity information that complements the GPS locations from radiocollars that are collected every 4 to 6 hours.
A more critical feature to be obtained form the lynx tracking will be information on lynx foraging patterns. Data on species killed, frequency of kills, hunting success, chase length, caching, and consumption patterns will be obtained from these tracking sessions. Because this foraging data is directly involved in conferring fitness to individual lynx, it can subsequently be used to strengthen habitat usage and selection studies with a fitness component. Collectively it will be possible to develop metrics regarding such measures as kills per km of trail traversed or kills per day. These types of foraging metrics can be used to investigate the functional response of lynx to fluctuations in prey species densities obtained from the general snow track surveys and specific prey species surveys (O’Donoghue et al. 1998).