Data from: Residential development reduces black bear (Ursus americanus) opportunity to scavenge cougar (Puma concolor) killed prey

Robins, Clint 1 ; Kertson, Brian2; Kachel, Shannon3

Published Dec 31, 2024 on Dryad. https://doi.org/10.5061/dryad.dv41ns249

Data files

Dec 31, 2024 version files 90.18 KB

Coug-Bear-Analysis-Ecology.csv

66.05 KB
Detection-History.csv

11.06 KB
README.md
13.06 KB

Abstract

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.

README: 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, clint.robins4@gmail.com
Dr. Shannon Kachel, Panthera, skachel@panthera.org
Dr. Aaron Wirsing, University of Washington, wirsinga@uw.edu
Dr. Brian Kertson, Washington Department of Fish and Wildlife, Brian.Kertson@dfw.wa.gov

Contact Clint Robins (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

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' < 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), 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) team, as well as the National Hydrography Database (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