# Use of Road Track Counts as Indices of Mountain Lion Presence

> Could you prove mountain lions are living in an area just by driving its dirt roads and looking for tracks? In Arizona and Utah, researchers tested road track searches against lions they already knew were there from radio collars. Over 14 months the searches found every resident lion, and good dirt roads beat fresh snow for finding them.

Summary by Kersey Lawrence, Original Wisdom. Updated 9 November 2026. Page: https://www.originalwisdom.com/tracking-literature/1986-van-dyke-brocke-use-road-track-counts/

## Citation and access

- **Authors:** Fred G. Van Dyke, Rainer H. Brocke and Harley G. Shaw
- **Year published:** 1986
- **Journal or source:** The Journal of Wildlife Management
- **Full citation:** Van Dyke, F. G., Brocke, R. H. and Shaw, H. G. 1986. Use of road track counts as indices of mountain lion presence. The Journal of Wildlife Management 50(1): 102–109.
- **DOI:** 10.2307/3801497
- **Access status:** Publisher link only
- **Where to find it:** https://doi.org/10.2307/3801497

## Tags

- **Species:** Mammals > Mountain lion
- **Region:** North America > United States
- **Tracking:** Individual identification; Sign surveys; Snow tracks; Track counts; Tracking; Tracks; Tracks and signs identification; Trailing
- **Behaviour and ecology:** Behaviour; Home range; Movement; Road crossings
- **Methods and technology:** Chi-square test; Detectability; Radio telemetry
- **Data type:** New field data
- **Observer qualification:** Not reported
- **Discipline:** Behaviour and ecology; Wildlife tracking
- **Year published:** 1986

## Detailed keywords

- **Species:** Studied: mountain lion (Felis concolor). The eastern subspecies (F. c. couguar) is the target population the study was meant to serve; the Florida panther (F. c. coryi) is mentioned for comparison of road crossing behaviour (information from the Florida Panther Recovery Team). Human boot prints were used as a standard to score tracking conditions.
- **Location and habitat:** Three study areas in the southwestern United States. Spider-Cross U Ranch area, about 1,200 km² in Yavapai County near Prescott, central Arizona: chaparral, chaparral-juniper (Juniperus utahensis) and pinyon (Pinus edulis)-juniper; road density 26 km per 100 km². Kaibab Plateau, about 3,600 km² in Coconino County, northern Arizona, near the Utah state line, including parts of Grand Canyon National Park: 1,525 to 2,800 m, subalpine grassland and conifer forest to great basin woodland and scrub; road density 43 km per 100 km² in the text (44 in Table 3). Escalante Study Area, about 4,500 km² in Kane and Garfield counties, southcentral Utah: 1,350 to 3,344 m, moderate winters, hot dry summers; road density 25 km per 100 km². Track searches were on dirt roads in three sections of the Escalante area (one of 518 km² and two of 466 km²). All areas had extensive public land.
- **Topics:** road track counts as population indices; detecting a species of uncertain status (the eastern mountain lion); road crossing frequency; road avoidance and road type (unimproved dirt, improved dirt, hard-surfaced); road density in home areas; tracking conditions and substrate (dirt versus snow); an objective tracking condition score using boot prints; track persistence and visibility; assigning tracks to individual lions (including two lions with missing toes); search effort (km searched per track set found); detectability of resident females, resident males, transients and cubs; relative versus absolute abundance. Inconsistencies in the paper: (1) the abstract and discussion say resident females needed the least effort to detect of all classes (51.1 km per track set), but in Table 7 cubs needed less (42.7 km); (2) the text gives the lowest detection rate, under Condition Class 4 (snow), as 29%, but Table 6 shows 33%; (3) the text says Kaibab lions did not appear to cross improved dirt or hard-surfaced roads, but Table 4 shows 25% and 50% of Kaibab lions crossing them, and Table 3 gives crossing rates for one lion on each; (4) the numbers of Spider-Cross U lions with each road type differ between Table 3 (5, 4 and 4) and Table 4 (8, 5 and 4); (5) the Kaibab road density is 43 km per 100 km² in the text and 44 in Table 3; (6) the Kaibab radio-tracking period is given as 1977 to 1980 in Table 1 and 1977 to 1981 or 1981 elsewhere.
- **Statistics or models:** Coefficients of determination (r²) for road penetration versus road crossing frequency; Spearman rank correlation (on ranked, normalized data, Blom 1958); chi-square test of independence; stepwise multiple regression of track finding rates (square-root transformed) on road condition, lion density and distance of collared lions to searched roads; 95% confidence limits; home areas by minimum area polygons (planimetry); road crossings reconstructed by assuming straight-line movement between radio locations.
- **Data type:** New field data. Radio-collared lions located from aircraft on the Spider-Cross U area 1971 to 1976 (1,014 locations, December 1972 to June 1976), the Kaibab Plateau 1977 to 1981 (349 locations, January 1978 to February 1981) and the Escalante area 1979 to 1982 (1,277 locations, December 1980 to February 1982). Seventy road track searches in the Escalante area, 15 December 1980 to 16 February 1982. Note: the PDF also contains the last page of the preceding article by the same authors (on reactions of mountain lions) and a JSTOR linked-citations page.

## Synopsis

### 1. What they did

By the late 1800s the eastern mountain lion was considered extinct, yet sightings kept being reported, and in 1973 the subspecies was listed as endangered although no population could be found. Earlier track count studies had never checked their counts against an independent estimate of how many lions were actually there. This study set out to test whether searching roads for tracks can show whether mountain lions are present, and how many, as a first step towards finding out whether lions survive in the eastern United States.

The authors worked in three western study areas where lions were radio-collared and located from aircraft: two in Arizona (Spider-Cross U and the Kaibab Plateau) and one in Utah (Escalante).

- Lions and roads (Arizona). They mapped each lion’s home area and measured the density of different road types in it. They reconstructed likely road crossings by drawing straight lines between consecutive radio locations, a deliberately cautious method that probably undercounts crossings.

- Track searches (Utah). Over 14 months they made 70 searches for lion tracks along dirt roads from a vehicle, 2,552 km in all, averaging 36.4 km per search. Most, if not all, resident lions in the searched sections were radio-collared, and searches were timed within 24 hours of the weekly flight that located them, so the researchers knew how many lions were present and how far they were from the roads.

- Scoring tracking conditions. Every 1.6 km, and wherever a lion track was found, the observer walked 10 steps across the road and scored each boot print from 1 (no print visible) to 4 (complete outline with all the sole detail). Each search was placed in one of four condition classes: poor, fair and good dirt, and excellent fresh powder snow.

- Counting tracks. They recorded three measures: independent track sets (tracks reliably assigned to different lions), all track sets, and track locations (points along the road where a lion track could be seen, counted every 0.16 km). Tracks were assigned to individual lions using known home areas, movements, family groups, track size and shape, and the missing toes of two lions.

### 2. What they found

Lions and roads

- Lions tended to live where improved dirt roads and hard-surfaced roads were scarce or absent. Of 26 home areas, 22 (85%) contained unimproved dirt roads, 15 (58%) improved dirt roads and only 6 (23%) hard-surfaced roads.

- On the Spider-Cross U and Escalante areas, lions’ home areas had fewer roads than the study area average. On the Kaibab, where roads were denser, lions’ home areas had about the same road density as the study area.

- Unimproved dirt roads were crossed most often. Most lions appeared to cross most of the unimproved dirt roads in their home areas.

- The more roads in a lion’s home area, the more often they crossed roads (r² = 0.65 overall). Males and females did not differ.

Track searches

- The searches found 58 independent track sets, 76 track sets and 122 track locations. On average 4.0 collared lions were present in the searched area at the time of each search (range 1 to 10).

- Lion density, distance to roads and tracking conditions together explained no more than 38% of the variation in track finding rates. Once searches were grouped by tracking condition, the picture became clearer: on good dirt roads (Condition Class 3), the density of resident females explained 61% of the variation in how often track sets were found.

- Areas with more lions and better tracking conditions needed fewer kilometres of searching per track found.

- Over 14 months, track searches detected every radio-collared resident lion (all 8 resident females and the 1 resident male), 78% of transients and 57% of cubs: 80% of the 25 lions overall.

- Good dirt gave the highest detection rate (93% of lions present) and the least effort, 56.9 km searched per track set found. Fresh snow gave the lowest detection rate (33% in the table; the text says 29%). Across all conditions it took on average 79.8 km of searching to find a track set.

- The paper states that resident females needed the least effort to detect (51.1 km per track set), but its own table shows cubs needed less (42.7 km).

### 3. What they concluded

- Lions appear to avoid improved dirt roads. For hard-surfaced roads this is less certain, because such roads are usually built in lower, open country that may simply be poor lion habitat.

- On good dirt, track finding is directly related to lion density, and is especially sensitive to the density of resident females and cubs. Track searches may not give reliable absolute numbers but may show relative abundance between areas, and they work well for finding out whether individual lions are present.

- Snow was less useful than good dirt. Snow makes tracks easy to see but wipes out all older signs, freezes, thaws and drifts, and lions tend to move less after heavy snow. Some high roads could not be driven after heavy snow, which may have biased the snow results.

- Mountain lions should be detectable in any eastern area with equal or higher road densities, with or without snow, if searches are done consistently by competent trackers. At most about 360 km of searching per 500 km² should find the track of any lion living there; under ideal conditions, less than 90 km.

- Resident females, the most important part of a population, should be relatively easy to detect. The authors found no support for the idea that resident lions live in the East undetected by deliberately avoiding roads. Transients are harder to detect, but they do not breed.

- They call for a serious investigation of the status of the eastern mountain lion and offer their results as a first step.

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

Tracking was central. Searchers drove dirt roads and stopped to examine every lion track, or doubtful track, they saw. Track sets were counted, followed along the road to record track locations, and assigned to individual lions where possible, using track size and shape, missing toes, and knowledge of home areas, movements and family groups. Tracking conditions were scored with a standard boot-print test. No trailing of lions away from the roads is reported.

### 5. Tracker or observer certification

Not reported. The paper does not say who searched for tracks or how experienced they were, although the results depend on finding and identifying lion tracks and telling individual lions apart. The authors’ own recommendation is that searches be done by “competent trackers.”

### 6. Other technologies, skills or innovations

- Radio collars, with lions located from aircraft about weekly.

- A simple, repeatable tracking condition score: the observer walks 10 steps across the road and rates each boot print from 1 to 4, giving a road score from 10 to 40.

- Three complementary track count measures (independent track sets, track sets and track locations), the last also measuring how long tracks persist and stay visible.

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

- Road track searches offer a practical way to find out whether mountain lions are present in areas where their status is unknown, such as the eastern United States.

- Because resident females are the easiest to detect and are central to population management, track searches can check the most important part of a population.

- Searches are most effective and efficient when done on dirt roads in good tracking conditions; the authors give effort guidelines (up to 360 km of searching per 500 km²).

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

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

- This is an early study that checked road track counts against a population known from radio-collaring, rather than assuming the counts reflect numbers.

- The boot-print score is a simple way to record tracking conditions on each survey, so that counts made on different days and substrates can be compared fairly.

- The finding that good dirt outperformed fresh snow is a useful reminder that clear tracks are not the same as useful tracks: snow resets the record, so only movement since the last snowfall can be read.

## Cite this summary

Lawrence, K. 2026. Summary of: Use of Road Track Counts as Indices of Mountain Lion Presence (Van Dyke and Brocke et al., 1986). Original Wisdom, Tracking Literature. https://www.originalwisdom.com/tracking-literature/1986-van-dyke-brocke-use-road-track-counts/