Objective The objective of our camera trap survey is to observe wildlife common to southwest Virginia and document their phenological (seasonal) changes. Additionally, we are comparing the use of field and "edge" habitats to other habitats such as forests and wetlands. The methods we used were based on published protocols for wildlife research using camera traps, and adjusted to reach our research objectives.
Location The field site we chose for this wildlife monitoring study is Selu Conservancy, located in Montgomery County, in southwest VA. The Conservancy is a 400 acre natural area dominated by relatively mature mixed oak forest. Other habitats include open fields and wetland floodplains on the banks of the Little River.
Motion-sensitive cameras were positioned away from areas of high anthropogenic traffic (eMammal, 2017). Previous studies suggest using forest service roads, game trails, and hiking trails (Kelley & Holub, 2008). This placement allows a clear path in at least one direction and creates a natural funnel that should ideally place animals approximately 3-4 meters from the camera (Kelley & Holub, 2008).
Habitats Habitat choice may vary depending on differing objectives. Certain species may be more abundant in one area compared to another at the field site so habitat choice may vary based on what species you are looking to observe. For example we noted more sightings of white-tailed deer in forest sites while eastern gray squirrels were observed more often in field settings.
Our objective was to consider seasonality as there will be a wide variety of environmental conditions between Febuary, 2018 (winter) and the completion of the data collection being April, 2018 (spring). Our team identified three main habitats of interest at Selu Conservancy:
Fields
Wetlands (Little River floodplain and two pond sites)
Forest trails
We deployed 18 trail cameras across Selu Conservancy (locations shown in the map above). Camera data was later monitored to assure the locations are successful in capturing photos of wildlife.
Set up and typical height of a wildlife camera. Photo taken by B. Grimm at Selu conservancy on 2/1/2018.
Camera Height Ideal camera height depends on the target species. Generally, it is suggested that cameras should be about 30-40 cm off the ground, so we attached our cameras at about knee height to medium-sized trees (Kelley & Holub, 2008). This allows the camera to capture both smaller mammals as well as larger mammals that may make use of the site. Additionally, tree choice is recommended to be more than 6” in diameter (eMammal, 2017). Cameras were secured to the tree and oriented parallel to the ground.
Avoiding False Triggers False triggers, photographs taken when wildlife are not present, are a frustrating part of wildlife monitoring using camera traps. To avoid these, we cleared the undergrowth within 6 feet of the view of the camera (Kelley & Holub, 2008). This prevents wind or other environmental conditions from stimulating the motion sensor on the cameras, and provides less obstructed photos (Kelley & Holub, 2008).
Photograph / Target Distance Through experimentation we found that target distances were enhanced when utilizing natural funnels and trails that allow for unobstructed views as well as clearing the undergrowth. We took advantage of natural trails created by animals as well as maintained nature trails. Each camera was tested for maximum trigger distance to ensure the cameras are functioning properly and to identify how far animals can be from the camera trap while still being detected.
What should be checked when cameras are set up? After deployment, each camera was checked that it is reporting the proper date and time for proper documentation. Additionally, cameras all were triggered as a test run to see if it was taking photos. After these have been checked, the camera was locked and secured to the tree to avoid theft.
What data should be collected when cameras are set up?
The Wildlife Camera Trap Deployment Data sheet we developed includes:
Camera #
Date, observer
Start and end times of animal event
Time of day (Day/Night)
Lunar phase
Temperature (°F)
Maximum # of species in photo
Weather conditions (e.g. rain, snow, none)
Animal behavior
General notes
For our data collection we used the "North Carolina Candid Critter Field Guide" as our standardized animal identification protocol. This created consistency across our collected data.
References
Kelly, M., Holub, E., 2008. Camera trapping of Carnivores: Trap success among camera types and across species, and habitat selection by species, on Salt Pond Mountain, Giles County, Virginia. Southeastern Naturalist 15(2):249-262
Hance, J. (2011). Camera traps emerge as a key tool in wildlife research. Yale School of Forestry and Environmental Studies: Yale E360 Accessed: https://e360.yale.edu/features/camera_traps_emerge_as_key_tool_in_wildlife_research
North Carolina's Candid Citters: Volunteer Resources, 2018. North Carolina's Candid Critter Field Guide: The Key to Animal Identification in North Carolina. North Carolina's Candid Critters.
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