DOI: 10.5061/dryad.64p5c
title: Data from: Camera-based occupancy monitoring at large scales: power to detect trends in grizzly bears across the Canadian Rockies

description: Monitoring carnivores is critical for conservation, yet challenging
 because they are rare and elusive. Few methods exist for monitoring
 wide-ranging species over large spatial and sufficiently long temporal
 scales to detect trends. Remote cameras are an emerging technology for
 monitoring large carnivores around the world because of their low cost,
 non-invasive methodology, and their ability to capture pictures of species
 of concern that are difficult to monitor. For species without uniquely
 identifiable spots, stripes, or other markings, cameras collect
 detection/non-detection data that are well suited for monitoring trends in
 occupancy as its own independent useful metric of species distribution, as
 well as an index for abundance. As with any new monitoring method,
 prospective power analysis is essential to ensure meaningful trends can be
 detected. Here we test camera-based occupancy models as a method to
 monitor changes in occupancy of a threatened species, grizzly bears (Ursus
 arctos), at large landscape scales, across 5 Canadian national parks
 (~21,000 km2). With n = 183 cameras, the top occupancy model estimated
 regional occupancy to be 0.79 across all 5 parks. We evaluate the
 statistical power to detect simulated 5–40% declines in occupancy between
 two sampling years and test applied questions of how power is affected by
 the spatial scale of interest (park level vs. regional level), the number
 of cameras deployed, and duration of camera deployment. We also explore
 several ecological mechanisms (i.e., spatial patterns) of decline in
 occupancy, and examine how power changes when focusing only on grizzly
 bears family groups. As hypothesized, statistical power increased with the
 number of cameras and with the number of days deployed. Power was
 unaffected, however, by the ecological mechanisms of decline, indicating
 that our systematic sampling design can detect a decline regardless of
 whether occupancy declined due to range edge attrition, ecological trap or
 other mechanisms. Despite their lower occupancy, power was similarly high
 for grizzly bear family groups compared to grizzly bears in general. We
 highlight which study design attributes contributed to high power and we
 provide advice for establishing cost-effective camera-based programs for
 monitoring large carnivore occupancy at large spatial scales.
description: All grizzly bear
 occupancy data- This dataset contains
 all detection-non-detection data for pictures from all grizzly bears. 1
 indicates at least one picture; 0 indicates no pictures; NA indicates
 camera not running. - Each row contains data from one camera site - Each
 columns contains data from one 4-day sampling replicate - Names of column
 corresponds to the number of the first day of each 4-day
 windowSteenweg_GrizzlyAll.csvGrizzly bear family occupancy dataThis dataset is similar to all grizzly bear data, but only contains detection-non-detection data for pictures of grizzly bear family groupsSteenweg_GrizzlyFam.csvGrizzly bear occupancy Site CovariatesThis dataset contains site covariates present in the top occupancy models for both grizzly bear occupancy data setsSteenweg_SiteCovariates.csv