LAUSR

Reliable population estimates are essential for the management of harvested species. Line transect distance sampling using pointing dogs is an established survey method for willow ptarmigan and has also been proposed for the monitoring of rock ptarmigan. In this study, we tested the assumptions of line transect distance sampling: 1) birds on the transect are detected with certainty, and 2) birds are detected at their initial location. We also investigated factors potentially influencing detection probability. We conducted field experiments in 2022 and 2023, walking line transects while accompanied by a pointing dog, towards GPS‐tagged rock ptarmigans. All rock ptarmigans within 0 and 30 m from the line transect were detected with 100% certainty. All birds were found close to their initial position, and most birds were passive (74%) as the surveyors approached. The best models to explain detection probability included the bird's distance to the transect and the time of day the experiment was conducted. The distance to the transect had a strong negative effect, which is expected in line transect distance sampling designs. The time of day of conducting experiments also had a non‐linear effect on detection probability, with lower detectability during midday compared to morning or evening. One possible explanation for this is that birds are more active during morning hours and evenings, and thus more easily detected by the dog. However, further investigation is needed to assess the usefulness of additional covariates to improve estimates. Overall, our results indicate that line transect distance sampling using pointing dogs does not violate key assumptions when applied to rock ptarmigan. We suggest that the existing line transect survey design used for willow ptarmigan can thus be extended to higher altitudes to also cover rock ptarmigan habitat.