DOI: 10.5061/dryad.crjdfn32t
title: Artificial nightlight alters the predator-prey dynamics of an apex carnivore

description: Artificial nightlight is increasingly recognized as an important
 environmental disturbance that influences the habitats and fitness of
 numerous species. However, its effects on wide-ranging vertebrates and
 their interactions remain unclear. Light pollution has the potential to
 amplify land-use change, and as such, answering the question of how this
 sensory stimulant affects behavior and habitat use of species valued for
 their ecological roles and economic impacts is critical for conservation
 and land-use planning. Here, we combined satellite-derived estimates of
 light pollution, with GPS-data from cougars (Puma concolor; n = 56), mule
 deer (Odocoileus hemionus; n = 263), and locations of cougar-killed deer
 (n = 1,562 carcasses), to assess the effects of light exposure on mammal
 behavior and predator-prey relationships across wildland-urban gradients
 in the southwestern United States. Our results indicate that deer used the
 anthropogenic environments to access forage and were more active at night
 than their wildland conspecifics. Despite higher nightlight levels,
 cougars killed deer at the wildland-urban interface, but hunted them in
 the relatively darkest locations. Light had the greatest effect of all
 covariates on where cougars killed deer at the wildland-urban interface.
 Both species exhibited functional responses to light pollution at fine
 scales; individual cougars and deer with less light exposure increasingly
 avoided illuminated areas when exposed to greater radiance, whereas deer
 living in the wildland-urban interface selected elevated light levels. We
 conclude that integrating estimates of light pollution into ecological
 studies provides crucial insights into how the dynamic human footprint can
 alter animal behavior and ecosystem function across spatial scales.
description: The data provided here are the final datasets used in each of the
 primary models used in the manuscript "Artificial nightlight alters
 the predator-prey dynamics of an<br> apex carnivore". These
 data are the processed (as described in the manuscript) values derived
 from GPS-collared cougars, mule deer, and the cache site locations of
 cougar-killed mule deer. Additional summary data are available in tables
 and supplemental materials associated with this manuscript. GPS location
 data are owned by the Utah Division of Wildlife Resources, Nevada
 Department of Wildlife, and the National Park Service. In Utah, Nevada,
 and Arizona cougars and mule deer are legally classified as big game
 species. Due to the potential for abuse, location data are considered
 proprietary and protected under state law. As such, they are not publicly
 available in their raw format. Researchers interested in obtaining copies
 of these data can formally request access through a Government Records
 Access and Management Act (GRAMA) or similar mechanism submitted to the
 appropriate agency.  
description: README files contain general info and column descriptions for the
 four main analyses reported in "Artificial nightlight alters the
 predator-prey dynamics of an<br> apex carnivore" by Ditmer et
 al. 2020 (Ecography; doi: 10.1111/ecog.05251). 
 <strong>Resource selection function of mule deer cache
 sites: </strong>README_CacheRSF_ColumnDescriptions.txt |
 Data: CacheRSF.csv <strong>Mule activity
 patterns:</strong> README_ActivityDeer_ColumnDescriptions.txt |
 Data: ActivityDeer.csv <strong>Integrated step
 selection function
 models:</strong> README_StepSelectionFunctions_ColumnDescriptions.txt | Data: CougarSSF_NoHouseDenVariable.csv, CougarSSF_WithHouseDensity.csv, DeerSSF_NoHouseDenVariable.csv, DeerSSF_WithHouseDenVariable.csv <strong>Assessing functional responses from light ratios of use vs. availability:</strong> README_FuncResponseRatios_ColumnDescriptions.txt | Data: CougarRatio.csv, DeerRatio.csv