Elk Camera Updates
Co-authored by Ally Magnin and Emily Donovan
You may have noticed recently on the blog that the Snapshot team has spent some time in the Northwoods conducting fieldwork in the elk grids. But what was our motive as researchers?
Wisconsin’s elk herds are dynamic and do not necessarily occupy the same area all the time. Young individuals may temporarily disperse, cows split off from larger herds to give birth, and the herd as a whole may shift their range as they seek out suitable habitat. While this is to be expected, it creates an interesting problem for camera trap research.
Since 2015, Snapshot Wisconsin has had a portion of our project dedicated to monitoring reintroduced elk herds. Cameras were deployed in grids much smaller than the usual Snapshot Wisconsin grid, increasing the density of cameras in the herd reintroduction area and making it more likely to capture photos of elk. As the herds shifted their range, however, some cameras no longer detected elk. To begin to address this mismatch between our elk grids and the herds’ ranges, Data and Spatial Analyst Emily Buege Donovan conducted an analysis.
Donovan began by combining several elk-related data sources to assess the quality of each camera site. Among these data sources were the most recent GPS locations of collared elk. A portion of the state’s elk are fitted with GPS collars, which transmit a location every 13 hours. GPS collar data is commonly used in wildlife research and management to better understand the movement patterns and resource selection of animal populations. In the present study, Donovan used these data to predict the likelihood that a camera will regularly detect elk. See Figure 1 for an example of the camera locations in relationship to the collar data. Camera locations in the northwest portion of the map have low probability of capturing elk, whereas cameras in the southeast have a high probability of capturing elk photos.
However, because not all elk in Wisconsin are collared, the collar data could not be used exclusively to determine whether a camera site should remain active in elk monitoring efforts. Donovan also needed to bring in the historical elk detections for each camera site. How long had it been since an elk was detected at this site? How many elk photos were taken by each camera? By combining the collar data, photo data, and several other factors, such as ease of access by the volunteer and habitat type, Donovan created a scoring system to determine the best camera locations. Low scoring cameras were marked for removal, and high scoring cameras were marked to stay on the landscape.
Once we determined which elk blocks should be removed, we reached out to the volunteer who was assigned to each of those blocks and requested their assistance in removing the camera. For the blocks that didn’t have a volunteer assigned, our team planned fieldwork for the summer of 2020 to remove the cameras.
Many of the cameras marked for removal were deployed over three years ago, so navigating to them proved difficult in some cases. We traversed tamarack swamps, bushwhacked through thick understory, hopped across streams, and puzzled over satellite imagery to reach each destination. Our team enjoyed the challenge!
In addition to removing old cameras, we also conducted camera checks on the blocks that didn’t currently have a volunteer assigned in order to get them ready for a new volunteer to monitor, and replaced cameras that had shown signs of malfunction. We made it a priority to take diligent notes about how to navigate to each camera site to make navigation easier for future volunteers.
Overall, it was a very productive field season that provided the team with the opportunity to step away from our computer screens and into the outdoors. It also gave us an even greater appreciation for the work our volunteers do to monitor their cameras.
Are you interested in monitoring a camera as a part of our elk project? Sign up today at elk.snapshotwisconsin.org. Applications are reviewed when blocks open up, and we will contact you with more information once you’re accepted!
Check out our other elk-related blog posts below: