DOI: 10.5061/dryad.dv41ns249
title: Data from: Residential development reduces black bear (Ursus americanus) opportunity to scavenge cougar (Puma concolor) killed prey

description: Large carnivores commonly scavenge on kills made by other species, but if
 and how this phenomenon is influenced by urbanization remains unclear. To
 address this knowledge deficit, we investigated whether housing density,
 along with demographic and environmental covariates, impacted the
 probability of American black bear (Ursus americanus) occurrence at cougar
 (Puma concolor) killed prey along the wildland-urban gradient of western
 Washington, USA. Under the refuge hypothesis, which stipulates residential
 development reduces opportunities for black bears to visit cougar prey
 carcasses by 1) altering cougar kill composition, and/or 2) drawing black
 bears to human subsidies, we expected the probability of bear presence at
 cougar kills to decline as housing density increased. Alternatively, under
 the pile-up hypothesis whereby reduced green space drives greater overlap
 and thus more frequent interactions among carnivores, we predicted that
 bear presence at cougar kills would increase with housing density.
 Occupancy models derived from forensic and remote camera evidence of bear
 visitation to carcasses at kill sites identified from 12 GPS-collared
 cougars indicated that the probability of bear presence at kill sites
 decreased when cougars foraged on small-bodied prey, increased in summer
 compared to autumn, and declined with increasing housing density. Indeed,
 the top model indicated a multiplicative decrease of 500 in the odds of
 black bear carcass visitation for every additional house/ha on the
 landscape, supporting the refuge hypothesis. These results suggest that
 residential development has the potential to alter intraguild
 relationships among large carnivores, even at modest levels where robust
 carnivore populations persist on the landscape, and may alter scavenger
 dynamics at carcasses where black bear presence is virtually eliminated.
  
description: Data was collected by capturing and collaring individual adult
 and subadult cougars in western Washington from 2013 - 2017. GPS locations
 were used to identify cougar kills, which were confirmed on the ground by
 researchers. Active kill sites involved visitation to kill locations while
 the cougar was still present or nearby (i.e., not finished consuming the
 prey species). Prey species killed was documented, along with prey
 physical characteristics, and scavenging species that visited the kill
 site.
description: # Data from: Residential development reduces black bear (Ursus americanus)
 opportunity to scavenge cougar (Puma concolor) killed prey Data for West
 Cascades Cougar Project (WCCP). The WCCP was located in western
 Washington, USA using data collected from individual GPS collared adult
 and subadult cougars (Puma concolor). Cougar kill sites were identified
 remotely and then documented in the field. ## Investigators Dr. Clint
 Robins, University of Washington,
 [crobins@contractor.usgs.gov](mailto:crobins@contractor.usgs.gov),
 [clint.robins4@gmail.com](mailto:clint.robins4@gmail.com) Dr. Shannon
 Kachel, Panthera, [skachel@panthera.org](mailto:skachel@panthera.org) Dr.
 Aaron Wirsing, University of Washington,
 [wirsinga@uw.edu](mailto:wirsinga@uw.edu) Dr. Brian Kertson, Washington
 Department of Fish and Wildlife,
 [Brian.Kertson@dfw.wa.gov](mailto:Brian.Kertson@dfw.wa.gov) Contact Clint
 Robins ([clint.robins4@gmail.com](mailto:clint.robins4@gmail.com)) with
 any questions. This manuscript has been accepted for publication
 (12/06/2024): Robins, C.W., B.N. Kertson, S.M. Kachel, and A.J. Wirsing.
 Residential development reduces black bear (Ursus americanus) opportunity
 to scavenge cougar (Puma concolor) killed prey. Ecology (accepted).
 Manuscript number: ECY24-0938 R scripts (file:
 Cougar-kill-site-black-bear-presence-analysis-Robins-et-al-2024.R)
 associated with these data files can be found here:
 [https://doi.org/10.5061/dryad.dv41ns249](https://doi.org/10.5061/dryad.dv41ns249) Data files include: ## Coug-Bear-Analysis-Ecology.csv This file contains data on cougar kill sites collected in the field. All data were collected by the authors. Blank cells, NAs, or N/As represent missing data. Dataset contents include dates of cougar kills, prey species killed, handling time (i.e., the hours a cougar was present at a carcass), the location of the kill site (UTM Zone 10, WGS 84), days before investigation (days between the last GPS location at a kill site and when researchers recorded kill site characteristics), presence of forensic evidence of black bear visitation, the maximum and minimum temperature during the kill interval in Fahrenheit (interval defined as the time between the first and last cougar GPS location at a kill site), habitat type, tree age, elevation, slope, housing density, and distance measures to roads, lakes streams, and residences. | variables | units | description | | :------------------------ | :-----------: | :--------------------------------------------------------------------------------------------------------------------------------------------------- | | FID | numeric | Unique identifier | | Coug ID | categorical | individual identifier for each study animal included in the analysis | | Sex | categorical | Male or Female | | Kill Date | date | date cougar killed prey species | | Camera Date | date | date camera trap was placed at kill site (if applicable) | | Date Investigated | date | date that researchers documented kill site characteristics in the field | | Days Before Investigation | days | number of days elapsed between kill date and date researchers visited the site | | Handling Time | hours | the number of hours the cougar was present (at 4-hour resolution due to 4-hour fix rate) | | Handling Time Count | count | handling time divided by 4-hour fix interval (strictly handling time treated as count data) | | Season | categorical | spring, summer, winter, fall | | Easting | numeric | UTM coordinates (Easting) | | Northing | numeric | UTM coordinates (Northing) | | Prey Species | count | Number of inflorescences | | Prey Type | categorical | Prey species killed, listed by common name | | Prey Size | categorical | 'small-bodied' &lt; 20 kg ≤ 'large-bodied'; with all prey other than older fawns, yearlings, and adult ungulates falling into the small-bodied category | | Prey Age | numeric | age of prey species killed for ungulate animals only (determined by dentition) | | Prey Sex | categorical | Male or Female | | Camera | presence | 'yes' for camera placed at site, 'no' for no camera | | Camera Species | categorical | Species listed by common name (if applicable) | | Scavenged Camera | presence | Presence (1) or absence (0) of scavenger species detected by camera | | Scavenged Forensic | presence | Presence (1) or absence (0) of scavenger species detected by forensic (directly by researcher) investigation | | Scavenged Combined | presence | Presence (1) or absence (0) of scavenger species detected by either camera or forensic method | | Species Scavenged | categorical | Scavenging species detected (listed by USFS FEIS species abbrevation system - first 2 letters of genus, then first 2 letter of species name) | | Max Temp F | degrees | Seven-day temperature maximum in degrees fahrenheit | | Max Temp Numeric | numeric | Seven-day temperature maximum as a number | | Min Temp F | degrees | Seven-day temperature minimum in degrees fahrenheit | | Min Temp Numeric | numeric | Seven-day temperature minimum as a number | | NLCD 2016 Habitat | categorical | habitat type for that kill site location defined by the 2016 National Land Cover Database (USGS data layer) | | Tree Ages | years | Tree age | | Elevation | meters | digital elevation model (DEM GIS layer) | | Slope | degrees | rate of change in elevation at each pixel (30x30m) | | Housing Density | residences/ha | Number of residences at square hectare scale (data acquired from county parcel records) | | Housing Distance | meters | Euclidean distance to nearest human residence/occupied built structure | | Road Distance | meters | Euclidean distance to nearest paved road of 1 lane or greater - data available in the National Transportation Dataset (USGS) | | Lakes Rivers Distance | meters | Euclidean distance to nearest lake or river as defined by the National Hydrography Dataset (USGS) | | Streams Distance | meters | Euclidean distance to nearest stream/creek as defined by the National Hydrography Dataset (USGS) | *N/As or NAs represent missing data. ## Detection-History.csv This file contains data on black bear detection at cougar kill sites collected forensically and via camera trap. All data were collected by the authors. Blank cells, NAs, or N/As represent missing data. | variables | units | description | | :-------- | :---------: | :--------------------------------------------------------------------------------------------- | | FID | numeric | Unique identifier | | Coug ID | categorical | individual identifier for each study animal included in the analysis | | Kill Date | date | date cougar killed prey species | | Forensic | presence | Presence (1) or absence (0) of scavenger species detected by forensic | | Camera | presence | Presence (1) or absence (0) of scavenger species detected by camera trap (first day, or day 0) | | Day 1 | presence | Presence (1) or absence (0) of scavenger species detected by camera trap | | Day 2 | presence | Presence (1) or absence (0) of scavenger species detected by camera trap | | Day 3 | presence | Presence (1) or absence (0) of scavenger species detected by camera trap | | Day 4 | presence | Presence (1) or absence (0) of scavenger species detected by camera trap | | Day 5 | presence | Presence (1) or absence (0) of scavenger species detected by camera trap | ## Description of the data and file structure The dataset is structured for analyses that assess the ecological correlates of black bear presence at cougar kill sites and of cougar prey handling (consumption) time. All distance measures are in meters, and 4-letter abbreviations for species names are structured as first two letters of the genus and first two letter of the species name per the USFS FEIS species abbreviation system; a separate column for species’ English common names is included. ## Sharing/Access information Housing and Landcover data were derived from the following sources: United States Geological Survey (USGS) landcover data ([https://www.usgs.gov](https://www.usgs.gov)), King County and Snohomish County parcel data (University of Washington media archive), and forest data from the Landscape Ecology, Modeling, Mapping and Analysis (LEMMA; [https://lemma.forestry.oregonstate.edu/data](https://lemma.forestry.oregonstate.edu/data)) team, as well as the National Hydrography Database ([http://www.nhd.usgs.gov](http://www.nhd.usgs.gov)). ## Code/Software R (version 4.2.1, 2022-06-23)code for analyzing black bear visitation to cougar kill sites using occupancy models is included in a separate R file, with directions for code workflow included in the R script. Statistical packages used in the script include: unmarked TMB lattice ggplot2 tidyverse MASS MuMIn lme4 LaplacesDemon