SPATIAL RELATIONSHIPS AND DEMOGRAPHICS OF GRIZZLY BEARS IN YELLOWSTONE NATIONAL PARK

• Main Author: Brasington, Tyler
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: figshare 2020
• Subjects: 60207 Population Ecology; FOS Biological sciences; 69999 Biological Sciences not elsewhere classified; Ursus arctos
• Online Access: https://dx.doi.org/10.6084/m9.figshare.11694813.v1; https://figshare.com/articles/SPATIAL_RELATIONSHIPS_AND_DEMOGRAPHICS_OF_GRIZZLY_BEARS_IN_YELLOWSTONE_NATIONAL_PARK/11694813/1

p.p1 {margin: 0.0px 0.0px 0.0px 0.0px; font: 12.0px Verdana; min-height: 15.0px} p.p2 {margin: 0.0px 0.0px 0.0px 0.0px; font: 9.0px Verdana} span.s1 {font: 12.0px Verdana} Since the early 1950’s, Grizzly bears (Ursus arctos horribilis) have been studied extensively within the Greater Yellowstone Ecosystem for the purpose of better understanding their social structure, reproduction capabilities, territorial range, habitat requirements, and other management related metrics. This study examined the spatial relationships of grizzlies, their surrounding habitat, average travel distances, elevation, and home ranges. Between February 23 and June 6, 2016 a total of 635 grizzly bear sightings were recorded in Yellowstone National Park. Among the 635 sightings, 209 were cubs (180 Cubs of the Year (COY), 22 one year olds, seven two year olds) A total of 13 females were observed with cubs. The average miles traveled for nine unique family groups (females with cubs) during the study was approximately 7.6 miles. Nine female family groups averaged a 7.2-mile perimeter and 1.3 sq. mi. area. A comparative six-month study in 2012 found similar home ranges and distances traveled. Based on seasonality, grizzly sightings fluctuate noticeably. April through June (819 sightings) is a very active time for females and cubs, along with courting behavior. Between July and August (180 sightings), bears moved to higher elevations, where they are less visible to observation. September through November (446 sightings) bears were observed at lower elevations and primarily found near carcass sites, usually wolf killed ungulates. This can be attributed to hyperphagia, a period of constant eating prior to hibernation. It is known that a shift in the distribution of grizzly bears in Yellowstone National Park and the Greater Yellowstone Ecosystem has occurred over the last few decades. The distribution shift should be considered by appropriate parties and if necessary, bear management units should be re-evaluated based on distribution analysis.