Black Bear Population Study
Hair snares play key role in estimating bear population
Several decades ago, few black bears lived in Missouri, but today the state’s bear population is healthy and growing. To estimate the size of bear populations, biologists look at several factors, but they begin with a simple, low-tech tool: barbed wire.
In what is known as a hair snare, biologists stretch barbed wire around three or more trees and then add scent lure to entice bears to approach. The barbed wire is set so bears need to crawl under or over it, and when they do, strands of their hair get caught. The hair is collected and sent to a lab for DNA analysis. Results show how many individual bears were detected. These numbers are used in population models.
MDC conducted an initial hair snare study in 2010–2011 as black bears started to make a comeback in the state. Hair snares were set along the Missouri-Arkansas border, the area where most bear sightings occurred at that time.
“We take the initial bear population estimate and our survival and recruitment estimates that we’ve generated from GPS-collared bears and use that data to track changes in the population over time,” explains MDC Bear Biologist Nate Bowersock.
Since 2011, the estimated bear population has grown from about 300 to nearly 1,000. In 2022–2023, Bowersock and staff conducted a new and larger hair snare study across most of the lower half of the state to reflect the expanding population.
“We distributed our hair snares based on radio collar data and bear sightings that we’ve had over the years,” says Bowersock.
The new study will not only provide an updated population estimate but will also look at associations between landscape features and bear densities, which will benefit both management and outreach activities.
“The outcome of this study will help us focus our outreach efforts in areas we expect to have higher bear densities down the road,” Bowersock says.
DNA analyses from the collected hair samples are still in progress; results are expected in 2025.
You can help MDC track the growing bear population by reporting bear sightings at short.mdc.mo.gov/4gF.
At a Glance
Hair Snare Study
- Hair is caught on barbed wire when bears pass through.
- DNA testing of hair shows how many individual bears passed through each snare.
- Data is used for population estimates.
About 1,000 hair samples were collected at hair snares in 2022 and 2023. DNA results are still pending.
Collaborators
Michigan State University, Mississippi State University, SUNY College of Environmental Science and Forestry




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This Issue's Staff
Editor - Angie Daly Morfeld
Associate Editor - Larry Archer
Photography Editor – Ben Nickelson
Staff Writer - Kristie Hilgedick
Staff Writer - Joe Jerek
Staff Writer – Dianne Van Dien
Designer - Marci Porter
Photographer - Noppadol Paothong
Photographer - David Stonner
Circulation – Marcia Hale