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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)

Citation

Connolly, Brian; Armstrong, Scott; Wozniak, Paul (2021), 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), Dryad, Dataset, https://doi.org/10.5061/dryad.qz612jmfk

Abstract

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.

Usage Notes

Sampling periods:

2018:   Camera traps were deployed at seven sites (four invasive shrub removed sites and three invasive shrub intact sites).  Deployment dates ranged from 31 July 2018 to 21 September 2018.  Camera trap recording was completed on 20 October 2018.  One camera (Dorm Invaded) malfunctioned and images were only recorded until 26 August 2018.

2019:   Cameras were deployed at thirteen sites (seven invasive shrub removed sites and six invasive shrub control sites).  Deployment dates ranged from 25 October 2019 to 1 November 2019.  Camera trap recording was completed on 6 December 2019.

2020:   Cameras were deployed for two sessions in 2020.  During the first 2020 session cameras were deployed at twelve sites (six invasive shrub removed sites and six invasive shrub control sites).  All cameras during this session were deployed on 21 July 2020 and were collected on 11 August 2020. During the second 2020 session cameras were deployed at twelve sites (six invasive shrub removed sites and six invasive shrub control sites).  Two cameras malfunctioned during this period (Dorm Invaded & Bearings Cleared).  All cameras during this session were deployed on 11 October 2020 and collected on 14 November 2020.

Column header names and variable description:

“Image_numb”:

Unique photo identifier associated with this observation

“site_name”:

Unique site names that identify each plot

“inv_trt”:

Invasive shrub treatment level. “Invaded” = plot did not have shrubs removed in summer 2018. “Cleared”=plot did have invasive shrubs removed in Summer 2018.

“Date”:

The date the observation was made

“Season”:

The season (e.g., “Summer”, “Fall”) the image was recorded

“Year”:

The combined year an image was recorded

“Season_year”:

The combined season and year an image was recorded.

“Time”:

The time of day an animal was active

“Time_deci”:

The time of day an animal was active transformed to a proportional scale where 12:00 a.m. is equal to 0.0 and 11:59 is equal to 1.0. For example, 12:00:00 p.m. would be equal to 0.5.

“Time_24deci”:

The time of day an animal was active transformed so that hours of observation time are recorded as whole numbers (range: 0-23) and the minutes and second of an observation are recorded as their corresponding proportion of an hour (range: .00-.99).  For example, the time “2:06:16” would equal “2.1544”.

“date_and_time”:

The untransformed combined record of date and time of animal observation.

“Temp”:

Recorded by the camera, the temperature (in degrees Celsius) at the time the image of the animal was taken.

“Animal_ID_common”:

The common name of the animal observed in the image.

“Animal_ID_scientific”:

The scientific name of the animal observed in the image.

“snow”:

Whether or not snow is present in the photo.  “0” = no snow is present in the image. “1” = there is snow present in the image.

“Number_of _Animals”:

The number of animals of the identified species present in an image.

Funding

National Institute of Food and Agriculture, Award: 2021-67019-33427

Eastern Michigan University, Award: James H. Brickley Endowment

Eastern Michigan University, Award: College of Arts and Science - Dean's Office award

Eastern Michigan University, Award: Department of Biology Award