Apex predators can influence ecosystems through density and behaviorally mediated effects on herbivores and mesopredators. In many parts of the world, apex predators live in, or are returning to, landscapes that have been modified by people, so it is important to understand their ecological role in anthropogenic landscapes. We used motion-activated game cameras to compare the activity patterns of humans and two mesopredators, coyotes (Canis latrans) and bobcats (Lynx rufus), in areas with and without an apex predator, the gray wolf (Canis lupus), in a multi-use landscape of the northwestern United States. In areas with wolves there was a significant increase in temporal niche overlap between the mesopredators owing to higher levels of coyote activity at all time periods of the day. Temporal overlap between mesopredators and humans also increased significantly in the presence of wolves. Coyotes exposed to wolves increased their activity during dawn, day, and dusk hours. The increase in coyote activity was greatest during the day, when wolves were least active. The direction of change in bobcat activity in areas with wolves was opposite to coyotes, suggesting a behaviorally-mediated cascade between wolves, coyotes, and bobcats, although these findings would need to be confirmed with further research. Our findings suggest that mesopredators in human-dominated systems may perceive humans as less dangerous than apex predators, that humans may be more likely to encounter mesopredators in areas occupied by top predators, and that behaviorally-mediated effects of apex predators on mesopredators persist in human-dominated landscapes.
Shores_2019_code_Figure_4_Table_2_Mesopredators change temporal activity patterns in response to an apex predator_GLMM
Annotated R code to reproduce species activity models with free R statistical software andR package glmmTMB
Shores_2019_data_Figure_4_Table_2_Mesopredator and apex predator activity records from game cameras_GLMM
Data of recorded species observations from game cameras. Description of columns in .csv file: Location = unique identifier corresponding to each camera location; study_area: Categorical variable identifying 1 of 4 study areas, N = Nc’icn (wolf area), S = Strawberry (wolf area), B = Bonaparte (non-wolf area), A = Aeneas (non-wolf area); date: unique identifier corresponding to dates starting with 0 = May 1, 2013 and 1095 = April 30, 2016; time_cat: time category of either night, dawn, day or dusk; season: winter or summer; bobcat/coyote/human/wolf_activity: number of photographs of the identified species indexed by time category, date, and camera sampling location; day: fraction of a day represented by each time category. This column is used in the model offset to account for the varying amount of time (10 hours vs. 2 hours) in the different time categories; wolf_presence: yes or no for whether a wolf pack was present in the study area.
Shores_2019_code_Figures 2 and 3_Temporal overlap analysis
Annotated R code to reproduce species temporal overlap analysis with free R statistical software and R package Overlap.
Shores_2019_data_Figure_2_bobcat_activity_times_temporal_overlap analysis
Data of times of species observations from game cameras from 5/1/2013 to 4/30/2016. Description of columns in .csv file: standardized clocktime: 24 hour time standardized to account for changes in daylength throughout the year; timed = standardized time in decimal degrees; timerad: standardized time in radians; zone: 1 = study areas with no resident wolf packs, 2 = study areas with resident wolf packs, species: species data contained in .csv file; imagedate = calendar date of the recorded observation, original_clocktime_dd = original clocktime, not standardized to account for changes in daylength over the course of a year, in decimal degrees; site: unique identifier for each camera location. W = study area with resident wolf packs, NW = non-wolf study areas
Shores_2019_data_Figures_2_and_3_coyote_activity_times_temporal_overlap analysis
Data of times of species observations from game cameras from 5/1/2013 to 4/30/2016. Description of columns in .csv file: standardized clocktime: 24 hour time standardized to account for changes in daylength throughout the year; timed = standardized time in decimal degrees; timerad: standardized time in radians; zone: 1 = study areas with no resident wolf packs, 2 = study areas with resident wolf packs, species: species data contained in .csv file; imagedate = calendar date of the recorded observation, original_clocktime_dd = original clocktime, not standardized to account for changes in daylength over the course of a year, in decimal degrees; site: unique identifier for each camera location. W = study area with resident wolf packs, NW = non-wolf study areas
Shores_2019_data_Figures_2_and_3_human_activity_times_temporal_overlap analysis
Data of times of species observations from game cameras from 5/1/2013 to 4/30/2016. Description of columns in .csv file: standardized clocktime: 24 hour time standardized to account for changes in daylength throughout the year; timed = standardized time in decimal degrees; timerad: standardized time in radians; zone: 1 = study areas with no resident wolf packs, 2 = study areas with resident wolf packs, species: species data contained in .csv file; imagedate = calendar date of the recorded observation, original_clocktime_dd = original clocktime, not standardized to account for changes in daylength over the course of a year, in decimal degrees; site: unique identifier for each camera location. W = study area with resident wolf packs, NW = non-wolf study areas
Shores_2019_data_Figures_2_and_3_wolf_activity_times_temporal_overlap analysis
Data of times of species observations from game cameras from 5/1/2013 to 4/30/2016. Description of columns in .csv file: standardized clocktime: 24 hour time standardized to account for changes in daylength throughout the year; timed = standardized time in decimal degrees; timerad: standardized time in radians; zone: 1 = study areas with no resident wolf packs, 2 = study areas with resident wolf packs, species: species data contained in .csv file; imagedate = calendar date of the recorded observation, original_clocktime_dd = original clocktime, not standardized to account for changes in daylength over the course of a year, in decimal degrees; site: unique identifier for each camera location. W = study area with resident wolf packs, NW = non-wolf study areas
Shores_2019_README_Mesopredators change temporal activity in response to recolonizing apex predator
File with descriptions of each data file, software and statistical packages used, list and description of all files associated with the paper