Project Results
Project Photo Highlights
Offal Wildlife Watching by the numbers
updated Nov. 2024
updated Nov. 2024
first year of image collection
hunters who have registered to help us collect data throughout Minnesota since project inception
gut piles filmed since project inception
different species captured on camera visiting project gut piles
images collected since 2018
Zooniverse volunteers who have helped identify and classify project images
Food Webs
Volume 37, December 2023, e00313
Abstract: Carrion is increasingly recognized as an important part of food web ecology that impacts multiple trophic levels and creates an arena for multiple species interactions. The pulsed nature of hunter-derived carrion, in the form of gut piles, is a form of carrion that has been overlooked in the study of food webs and scavenger interaction. The Offal Wildlife Watching project aims to better understand scavenger species that benefit from offal and how they interact with each other and this resource. Through citizen science efforts by hunters and Zooniverse volunteers, we have collected and analyzed over 230,000 images of scavengers at white-tailed deer gut piles. At some gut piles, we have observed barred owls and bobcats both scavenging at hunter provided gut piles and preying on rodents that were also attracted to the gut pile. This interaction, made possible by a food subsidy that is historically novel in time and space, may have implications for rodent populations, predator survival and fecundity, and the activity patterns of both. Continued research and investigation will shed light on the impacts of cascading carrion on species interaction.
One of the best aspects of participatory science is that volunteers can observe and suggest things that are going on at gut piles that researchers might miss. One hunter volunteer suggested that there is more going on than just scavenging. Barred owls, for example, are recorded on many of the gut pile images. We know they are feeding on the guts themselves because we see this in several images. What’s interesting, however, is what might be attracting owls to this food resource. Owls detect their prey through sight and sound. Since gut piles aren’t moving or making noise, what is attracting owls to the gut piles? The volunteer suggested that perhaps they were hunting other scavengers. And lo and behold, we see this in some images!
The question now is: are owls hunting rodents and getting a free meal of guts after, or do they find the gut pile and opportunistically use it to hunt rodents? We don’t just see this in owls, we have also recorded bobcats playing with captured rodents.
patterns of rodent and barred owl detections at gut piles throughout the day from OWW participant cameras.
Journal of Extension
Volume 63, Issue 1
Abstract: Offal Wildlife Watching is a participatory science project that engages deer hunters in wildlife research. The goal of the project is to better understand the ecology of scavenger species that visit deer gut piles across Minnesota. We asked hunters to deploy remote cameras at white-tailed deer gut piles that resulted from their freshly killed deer. Thus far 117 hunters have contributed images and recorded at least 49 different scavenger species. This project is a natural fit in Extension programs and can easily be adapted to other hunted species, biomes, and locations
Dominant Wildlife at Offal in Minnesota Biomes
The graph below shows the proportion of images (not individuals within the images) in each biome that recorded a certain species group from 2018-2021. Each bar represents a different species grouping. Unsurprisingly, birds dominate most of the images we see. However, in the prairie, we see more carnivore images. Since the prairie region is pretty open, we expected birds to see gut piles quickly and dominate them, often before carnivores can even smell them, but the data shows carnivores are finding them quickly.
