Locations of black bear (Ursus americanus) reproduction in Nevada from camera-trap data
Data files
Nov 15, 2023 version files 4.22 KB
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data.RData
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README.md
Abstract
Understanding factors creating species range boundaries is a fundamental goal of ecology and biogeography. American black bears recolonized the western Great Basin from the Sierra Nevada in the late 1900s but this expansion has not proceeded further into the Great Basin despite the presence of suitable habitat. We deployed 100 camera traps across the occupied range of black bears in the U.S. state of Nevada and tracked bear detections across 3 years. A scent lure was applied in camera trap viewsheds to increase bear detections. We classified detections of bear cubs separately from detections of only adult bears, to serve as an indicator of black bear reproduction occurring at sites. Data are provided in the format necessary for a analysis with multistate occupancy model. Analysis of these data revealed low incidence of reproduction at the periphery of black bear range in the western Great Basin, which likely contributes to range boundary formation.
README: Locations of black bear (Ursus americanus) reproduction in Nevada from camera-trap data
Camera trapping data set for American black bears in northwestern Nevada from 100 sites sampled across three years, with detections, indicated separate from adult bear detections.
Description of the Data and file structure
Data is provided as a named list in R
- y = 3-dimensional array of black bear detection-nondetection data. 300 rows for each site of 100 sites, 9 columns for each secondary sampling week within seasons. The third dimension is years (3).1 = no bears detected, 2 = adult bear detected, 3 = cub(s) detected.
- site = unique site identifier, used to specify random effect in multistate occupancy model.
- conifer = proportion of conifer forest and woodland within a 5km radius of sites. Data are centered and scaled.
- region = binary ecoregion covariate indicating is site was located in northwestern Forested
- nsite = number of sites samples (100)
- nsurveys = number of secondary sampling periods each year (9)
- nyears = number of years (3)
- Missing data code = NA
Sharing/access Information
Links to other publicly accessible locations of the data:
Was data derived from another source? Yes, conifer variable (link 1) and ecoregion variable (link 2)
If yes, list source(s): USDA/DOI LANDFIRE 2016 data set (https://www.landfire.gov/evt.php),
US EPA North American Ecoregion Level I data set (https://www.epa.gov/eco-research/ecoregions-north-america)
Methods
Data was collected with camera traps at 100 locations in Northwestern Nevada, spaced approximately 7 km apart. A scent lure was applied in the viewshed of the camera to increase the detection of black bears. Black bear detections were grouped into 30-day periods that indicated whether black bears were or were not detected at a site during a given time period. We separated out cub detections as indicators of black bears reproducing in the vicinity of a site. The black bear hibernation period (Dec-Feb) was excluded from detection histories. Locations were surveyed for 3 years (2018-2020).
Usage notes
The data is provided as an RData object with all data required to run a multistate occupancy model included in the object. The file can be read using the load function in program R.