Wildlife activity timing in shrub-invaded and shrub-removed oak-hickory forest at Fish Lake Environmental Education Center (Eastern Michigan University; Lapeer County, Michigan, USA)

Wildlife activity timing reflects an individual animal’s need to balance activities that improve fitness with timing that minimizes risk of exposure to extreme climatic conditions, predation risk, and other threats to survival and growth.  Habitat structure, such as the type or amount of vegetative cover, can have a direct effect on the timing and amount of wildlife activity and these habitat-mediated differences in animal activity can translate to shifts in important species interactions (e.g., predator-prey interactions, seed predation, and secondary seed dispersal).  Invasive shrubs (e.g., Amur Honeysuckle, Autumn Olive, and Common Buckthorn) significantly alter habitat structure and directly affect overall activity and the timing of wildlife activity in upper Midwest United States forests.  Here, we provide trail camera data records of wildlife activity timing from fourteen 20 × 20m oak-hickory forest plots located at the Fish Lake Environmental Education Center (Lapeer, Michigan, USA); we mechanically removed and chemically treated Autumn Olive and Amur’s Honeysuckle from seven of the plots and seven plots remained as shrub-invaded reference plots.  Data were recorded in two consecutive fall sessions (2019 & 2020), and one Summer Session (2020); see methods for specific windows of camera recording durations.  These animal activity data have multiple uses that range from the synthesis of primary research to environmental education. With specific focus on environmental education, these data are particularly useful in exploring concepts in wildlife management (e.g., the influence of habitat structure on cervid activity), developing spatial maps of activity using a local network of cameras, and exploring management of time and date formatted data in statistical programs (e.g., R, JMP, Minitab, Excel) to efficiently summarize trends over time.

Methods
Study Sites and Invasive Shrub Removal

All 14 sites were located at Fish Lake Environmental Education Center (Eastern Michigan University; Lapeer County, Michigan).  In June 2018, seven of the 20 × 20m plots were cleared of Autumn Olive and Amur Honeysuckle while the remaining seven plots were left invaded as reference plots.  Across all sites, pre-removal invasive shrub stem density ranged from 0.64-2.04 stems/m2; please contact Brian Connolly for more information on site characteristics. More site-specific details will follow in subsequent published data and manuscripts, but we will gladly provide more details sooner if data users are interested. 

Equipment, Data Collection, and Intervals:

To record animal activity, trail cameras (Bushnell Trophy Trail Camera 20MP [HD_119717CW]) were loaded with 32 GB memory cards (SanDisk 32 GB Ultra SD Memory Card) and secured at 0.5-0.75m height above the ground on a tree located roughly in the center of each plot. Data collection durations, defined below, were targeted to extent for >1 month during each sampling interval to capture differences in wildlife activity during different lunar phases. Both fall sessions exceeded one month, but logistical constraints limited summer 2020 sampling to a three-week duration. Each camera had identical parameters for triggering mechanisms and image recording.  Each camera was set to “High” trigger sensitivity and each camera was set to take three consecutive photos once triggered.  

Data Processing

At the completion of each image capture duration, images were downloaded and the animal activity was indexed on a spreadsheet by a single observer.  A list of the types and categories of data we collected are listed below in the “Usage Notes” section. We adopted the following rules regarding data entry:

An activity observation entry for an animal was only permitted if the animal was visible within the image frame and identifiable to the level of genus or more specific.
Activity observation entries of any unique wildlife species must be separated by at least 10 minutes from the last previous entry for that animal.  This data management step helped introduce a small measure of independence between each unique observation.
Species names were ascribed to wildlife images based on known species occurrence ranges in this region of Michigan and live-trapping efforts conducted on these sites.
Images of birds were not included in this data set and observations were limited to mammalian wildlife activity.

Data collection and update policy

Data collection of animal activity at these sites may occur intermittently as a function of student-led research projects and faculty-led research inquiries. Data on animal activity on these plots will be updated as possible.