Hunters help U researchers with window into the world of scavengers

University of Minnesota researchers remain interested in the messy and, perhaps, offputting markings of a deer hunt: a gut pile.

The Offal Wildlife Watching project team wants hunters, after field-dressing their deer, to set up trail cameras for a month at the sites, which have become a window into the world of scavengers.

Over five hunting seasons, researchers have been learning what descends on whitetails' internal organs, or offal. They say the study will help fill a knowledge gap in an area that is all about scale: About 150,000-200,000 whitetails are harvested annually in Minnesota, creating tons of offal on the land. How many species use it? Are some more common than others? How does it vary across Minnesota habitats?

"If we didn't hunt this time of year, that wouldn't be available," said Ellen Candler, a postdoctoral researcher among the analysts. "Deer are pretty healthy this time of year. They don't just die, typically. Not in that mass.

"So, understanding what our impact is on those species — whether it is positive? Do we impact the survival of some of those scavenger species? That is not a question we can directly get at with our research, but it is something the research can inform. What could possibly be the negative impacts? What are we provisioning as hunters?"

Another season, another request

The project recently received state funding for two additional years. It also received money from the Environment and Natural Resources Trust Fund that helped buy about 150 remote cameras to lend to hunters, Candler said. At least 40 camera kits remain. Some of the new cameras have been deployed after special hunts in the Three Rivers Parks District, Dakota County, and elsewhere.

Using social media and other communication means, the project has scored repeat participants. Some hunters use their own trail cams. Researchers also have relied on partnerships with groups like the Minnesota Master Naturalist Program and Bluffland Whitetails Association.

Candler said to date the project has brought in hundreds of thousands of images from across Minnesota. Researchers use Zooniverse, a citizen science platform where the public can help them wade through the volume, and discuss or question what they've seen.

Hunters who are interested in aiding the research can register at offal.umn.edu.

What has turned up on camera cards?

At least 50 different species. Crows, ravens and eagles have been among the most common. There have been four types of woodpeckers; a trio of bobcats; fishers and American martens (in the weasel family); flying squirrels; rabbits; chickadees — and even the occasional deer, Candler said. While woodpeckers might be surprising, Candler likened their appearance to suet blocks at bird feeders. Regarding deer, Candler said a nutritional deficit might be the trigger. Plus, the remains might exist on a commonly used wildlife path.

Does research extend to threats to wildlife, like lead ammunition fragments or disease?

Candler said those areas aren't a goal, but said the project does talk with the Minnesota Center for Prion Research and Outreach, focused on chronic wasting disease.

"We're in constant talks with them about how [scavengers at gut piles] might impact disease spread," Candler said, "either between deer or how scavenger species might influence that."

Photos reveal a hidden world

Beyond the images of guts and scavengers is the odd intrigue of looking at an activity normally hidden to most humans. The photos can be inherently interesting and, in the case of those shot with high-end cameras, striking. Candler agreed and equated them to experiences and interactions with wildlife that occur in the "sit-and-wait" quiet outdoors.

"You get this view into nature that you would not otherwise see. We had barred owls and bobcats hunting rodents at the gut piles which have been super interesting. … Things you otherwise wouldn't see. Just to get a glimpse into the lives of these scavengers and how we influence them even when we leave. Whether that be positive or negative."

Related program: A remote camera workshop and discussion is Saturday at Eastman Nature Center in Dayton. Details are here.