# A Snow-tracking Protocol Used to Delineate Local Lynx, Lynx canadensis, Distributions

> When should you go looking for lynx tracks? Not the morning after fresh snow, according to this simulation: a survey a week after snowfall was over three times as likely to cross a lynx trail. In Montana, snow-track surveys mapped the same lynx range as radio collars, and in Wyoming the team followed doubtful, wind-scoured tracks to daybeds and confirmed them as lynx from hairs frozen in the snow.

Summary by Kersey Lawrence, Original Wisdom. Updated 9 November 2026. Page: https://www.originalwisdom.com/tracking-literature/2004-squires-mckelvey-snow-tracking-protocol-used/

## Citation and access

- **Authors:** John R. Squires, Kevin S. McKelvey and Leonard F. Ruggiero
- **Year published:** 2004
- **Journal or source:** The Canadian Field-Naturalist
- **Full citation:** Squires, J. R., McKelvey, K. S. and Ruggiero, L. F. 2004. A snow-tracking protocol used to delineate local lynx, Lynx canadensis, distributions. Canadian Field-Naturalist 118(4): 583–589.
- **DOI:** 10.22621/cfn.v118i4.60
- **Access status:** Hosted: U.S. government work, not subject to copyright in the United States
- **PDF:** https://www.originalwisdom.com/wp-content/uploads/2026/11/2004_Squires_and_McKelvey_etal_a-snow-tracking-protocol-used-to-delineate-local-lynx-distributions.pdf

## Tags

- **Species:** Mammals > Canada lynx
- **Region:** North America > United States
- **Tracking:** Beds; Hair; Sign surveys; Snow tracks; Track measurements; Track photographs; Tracking; Tracks; Tracks and signs identification; Trailing
- **Behaviour and ecology:** Behaviour; Daily travel distance; Home range; Movement; Tortuosity
- **Methods and technology:** Detectability; DNA; Geographic Information System (GIS); Global Positioning System (GPS); Hair sampling; Movement simulation; Radio telemetry; Simulation; Utilization distribution; Very high frequency (VHF) radio collars
- **Data type:** Modelling or theoretical; New field data; Protocol or guidelines
- **Observer qualification:** Reported but not validated
- **Discipline:** Wildlife tracking
- **Year published:** 2004

## Detailed keywords

- **Species:** Studied: Canada lynx (Lynx canadensis). Main prey named: snowshoe hare (Lepus americanus). Tracks of other carnivores were also recorded, but the paper does not name them or report them. Mentioned from other studies: fisher (Martes pennanti).
- **Location and habitat:** Garnet Range (Garnet Mountain Range), western Montana, United States: about 80% forested, mainly Douglas-fir (Pseudotsuga menziesii) and subalpine fir (Abies lasiocarpa) habitat series, with Engelmann spruce (Picea engelmannii) and lodgepole pine (Pinus contorta); 1160 to 2090 m; much of it logged within the past 25 years; bordered by hay fields and big sagebrush (Artemisia tridentata) and wheatgrass (Agropyron spp.). Wyoming Range and Salt River Range, about 80 km southwest of Jackson, west-central Wyoming, United States: mixed conifer forest of subalpine fir, Engelmann spruce, lodgepole pine, whitebark pine (Pinus albicaulis), Douglas-fir and quaking aspen (Populus tremuloides); 1981 to 3353 m. Observers were trained at the authors’ long-term lynx study area near Seeley Lake, Montana.
- **Topics:** snow-track survey protocol; detecting a rare, threatened carnivore (listed as Threatened under the U.S. Endangered Species Act); presence and absence; local distribution; detection probability and days since snowfall; number of survey visits; 8 x 8 km survey grid; high and low priority habitat; track misidentification and false positives; genetic confirmation of tracks (the track as a “collection device”); hair from daybeds; observer training by back-tracking; snowmobile and snowshoe surveys; adaptive cluster sampling for larger areas. Inconsistencies in the paper: (1) the abstract reports 189 lynx tracks in the Garnet Range, but the results give 37 plus 37 survey detections and 115 plus 53 tracks seen outside the formal survey (242 in all; 189 matches 37 + 37 + 115); (2) the abstract reports six lynx tracks in Wyoming, but the results list 1 + 1 + 4 + 1 = 7, and the text later refers to “the 7 track detections”; (3) the text gives about 14 telemetry locations per lynx and points to Figure 2B for telemetry and 2A for the comparison, while the figure caption gives 13 locations per lynx and labels telemetry as 2A and track detections as 2B.
- **Statistics or models:** computer simulation of lynx tracks (track tortuosity from 15 back-tracked lynx; daily travel drawn at random from 1.0 to 4.0 km; 100 km² circular home ranges; a straight 8 km transect) to estimate the probability of detection by number of visits and days since snowfall (1, 3 or 7 days); 95% fixed kernel home range from telemetry; overlay of telemetry and snow-track distributions; mean, standard deviation and range of track elevations.
- **Data type:** New field data: Garnet Range snow-track surveys and trapping in winters 2001 to 2002 and 2002 to 2003; Wyoming and Salt River ranges surveys in winters 1999 to 2000, 2000 to 2001 and 2001 to 2002. Modelling (computer simulation). A survey protocol. Table 1 summarises published lynx daily travel distances from other studies. Wyoming Game and Fish Department trapping records from winter 1996 to 1997 (personal communication).

## Synopsis

### 1. What they did

Canada lynx are listed as threatened in the contiguous United States, so land managers need to know where they live. Hair-snagging pads can confirm lynx with DNA, but they cannot tell a resident population from a single animal passing through. The authors set out to build a snow-track survey for lynx that covers the whole landscape fairly and deals with the risk of misidentified tracks.

- Computer simulation. They back-tracked 15 radio-collared lynx and mapped their tracks with a Global Positioning System (GPS) unit. From these, they measured how winding (tortuous) real lynx tracks are. They then simulated lynx travelling 1 to 4 km a day inside a 100 km² home range, with an 8 km survey transect running through it, to see how likely a survey would be to cross a track after 1, 3 or 7 days since the last snowfall, and with more visits.

- The survey protocol. Using a Geographic Information System (GIS), they laid an 8 x 8 km grid over each study area. Units in moist subalpine fir forest (which lynx use most) were high priority and surveyed at least twice a winter; drier, open forest was low priority and surveyed once; open country and high alpine areas were not surveyed. Observers searched 10 km per unit, mostly by snowmobile at 15 to 20 km per hour on roads and trails, or on snowshoes, choosing routes through forest with dense cover (good snowshoe hare habitat).

- Recording and confirming tracks. Every lynx track (and other carnivore tracks) was located by GPS. Rare carnivore tracks were measured (stride, straddle, length, width, depth) and photographed. In Wyoming, they followed presumed lynx tracks to look for scats and daybeds, and picked hairs frozen into the beds for DNA testing.

- Testing against telemetry. In the Garnet Range, Montana, where they believed most lynx were radio-collared, they compared the area where tracks were found with the lynx distribution from radio telemetry (a 95% kernel home range of all locations). They also surveyed the Wyoming and Salt River ranges, where lynx were thought to be present but scarce.

### 2. What they found

Simulations

- With one visit, the chance of detecting lynx tracks rose from about 0.23 one day after snowfall to 0.78 seven days after.

- With three visits, it rose from 0.58 one day after snowfall to about 0.95 seven days after.

- Two visits found tracks about 80% of the time once more than 3 days had passed since snowfall.

Garnet Range, Montana

- They surveyed 242 km of roads and trails in winter 2001 to 2002 and 438 km in 2002 to 2003.

- They recorded 37 lynx track detections in 4 of 12 survey units the first winter, and 37 in 4 of 16 units the second.

- They saw a further 115 and 53 lynx tracks outside the formal surveys, during trapping in areas of high lynx use.

- Lynx tracks were at an average elevation of 1839 m (range 1443 to 2012 m).

- Seven lynx were collared (five in the first winter, two in the second), which the authors believed was a local census, though they could not test this.

- The telemetry home range (96 locations from 7 lynx) contained 97% of the tracks found on the surveys. The two methods gave the same general distribution.

Wyoming and Salt River ranges

- They surveyed 1055 km in 32 units (1999 to 2000), 1103 km in 37 units (2000 to 2001) and 1080 km in 34 units (2001 to 2002).

- They found two lynx tracks in the first winter, five in the second, and none in the third. Wyoming Game and Fish Department biologists also saw tracks of a family group.

- Two tracks from the first winter looked like lynx but were poorly defined: wind had scoured the snow, leaving each print as a raised pedestal. The team followed them for about 200 m to daybeds and collected five hairs; two had enough DNA, which confirmed lynx.

- Five of the seven detections fell in the same area of the northeastern Wyoming Range where two lynx trapped by state biologists had spent the winter of 1996 to 1997.

### 3. What they concluded

- Snow-track surveys spread fairly across all available habitat can at least coarsely map the local winter distribution of lynx, not just presence or absence.

- In Wyoming, local managers believed lynx were spread through both ranges, but the surveys showed they were rare and confined to a small area in the north of the Wyoming Range.

- Where lynx are rare, a single misidentified track can have serious management consequences. The authors suggest treating the track as a “collection device” for genetic samples rather than the main means of identification, and recommend genetic confirmation whenever correct identification of a set of tracks is critical.

- Surveys are usually done a day or two after fresh snow, when tracks are clearest, but detection is much higher several days later. Confirming older tracks with DNA lets surveys run when detection is high, even in poor tracking conditions.

- The key elements of their surveys were: sample units spread across the landscape but focused on good habitat; a defined, consistent search effort per unit; search intensity matched to the simulated detection rates; well-trained technicians; carefully documented, GPS-referenced track identifications; and searching lynx tracks for genetic samples.

- The method is labour intensive. For whole regions or states, the authors suggest adaptive cluster sampling.

### 4. How tracking was or was not used

Tracking is the core of the study. Observers searched for lynx tracks in snow from snowmobiles and on snowshoes, recorded each one by GPS, and measured and photographed rare carnivore tracks. Crossings of the same animal less than 100 m apart counted as one detection. The researchers back-tracked radio-collared lynx to map real travel routes for the simulation, and in Wyoming they trailed presumed lynx tracks about 200 m to daybeds to collect hairs for DNA confirmation of poorly defined, wind-scoured tracks.

### 5. Tracker or observer certification

Reported but not validated. Observers were trained by back-tracking radio-collared lynx in varied forest, snow and terrain at the study area near Seeley Lake, Montana, and after this training the authors “assumed that all observers could recognize lynx tracks”. Their skill was not tested. The authors list well-trained technicians as a key element of the protocol, and they relied on DNA, not observer skill, to confirm the rare Wyoming tracks.

### 6. Other technologies, skills or innovations

- Trimble GEO Explorer III GPS units, used to map back-tracked lynx routes (a point every 2 seconds) and to record track locations.

- Computer simulation of lynx travel based on real track tortuosity.

- An 8 x 8 km survey grid drawn in GIS, with habitat-based priorities.

- Collecting hairs with tweezers from daybeds after clearing loose snow down to the frozen bed layer; DNA analysis by the Rocky Mountain Research Station’s Wildlife Genetics Laboratory.

- Box traps with carrion, beaver castor and visual lures (pie plates and wings); very high frequency (VHF) radio collars; mostly aerial telemetry.

### 7. Implications for conservation (from the paper)

- Managers need reliable distribution data for lynx at the southern edge of their range, where they are threatened.

- False positives can overstate where a rare species lives, and misidentification can have serious management impacts for species listed under the U.S. Endangered Species Act; genetic confirmation guards against this.

- Snow-track surveys can pick up changes in lynx occupancy quickly across large areas, and even a coarse map of local distribution is useful to habitat managers.

### 8. Implications for tracking (Original Wisdom's observations)

_These are Original Wisdom's observations, not the authors'._

- The simulations show that the “best” tracking conditions (a day after fresh snow) are not the best survey conditions: older snow holds more tracks, so the chance of crossing one is far higher. The trade-off is that older tracks are harder to identify, which the authors handle with DNA rather than observer skill.

- Observers were trained by back-tracking known lynx but never tested, and the authors fall back on genetic confirmation when tracks were unclear. A validated tracker evaluation would be another way to show how far track identifications can be trusted.

## Cite this summary

Lawrence, K. 2026. Summary of: A Snow-tracking Protocol Used to Delineate Local Lynx, Lynx canadensis, Distributions (Squires and McKelvey et al., 2004). Original Wisdom, Tracking Literature. https://www.originalwisdom.com/tracking-literature/2004-squires-mckelvey-snow-tracking-protocol-used/