Abstract 74 – Documenting Bear Dens using Light Detection And Ranging (LiDAR) Technology

Tyler Brasington, Jessica M. Hadley, Justin K. Schwabedissen

During hibernation, American black bears (Ursus americanus) and grizzly bears (Ursus arctos
horribilis) in the Greater Yellowstone Ecosystem (GYE) create dens for protection from harsh
winter environments and to give birth to cubs. Previous studies have acquired den site
characteristics through physical measurements recorded by researchers in the field. Using the
light detection and ranging (LiDAR) sensor onboard an Apple iPad Pro, we scanned the interior
of bear dens (n = 9) located in the GYE to generate point clouds of den structure. We then
generated a three-dimensional digital model of each den by processing the point clouds using a
combination of available software packages. Computer-generated LiDAR dimensions from the
three-dimensional LiDAR models were compared to physical den measurements of the dens
recorded by field personnel. The LiDAR generated measurements were within 2% of the
physical measurements for every bear den surveyed. Tablet-based LiDAR technology exhibits
easy operability and can be readily integrated into den site surveys. The resulting three-
dimensional digital models can be catalogued for future studies and provide the advantage of a
more robust dataset compared to traditional measurements. This is the first known use of
LiDAR to measure bear den characteristics in the field.