Oregon Mule Deer Biggs Annual Ranges

Most of the Biggs mule deer herd is nonmigratory. Annual ranges are scattered throughout the relatively flat, low-elevation landscape near rivers such as John Day River, Deschutes River, Buck Hollow Creek, Ward Creek, and Hay Creek. Northern seasonal ranges occur in unforested expanses of grassland and Artemisia tridentata tridentata (basin big sagebrush), which are interspersed with farmland, nonnative annual grasses, and portions of intact sagebrush steppe. Grain and hay are economically important crops in the north where many mule deer ranges overlap winter wheat fields. Areas around the John Day Canyon and Deschutes River Canyon allow mule deer to access unfarmed habitat. Compared to the northern ranges, the southern ranges are more mountainous and feature higher proportions of Juniperus occidentalis (western juniper). Only 6.5 percent of the Biggs mule deer herd tracked for >100 days exhibited migratory behavior and distinct seasonal ranges. These three GPS-collared mule deer in the southern region of the Biggs herd management unit migrated to TV Ridge, Shoestring Ridge, and Ward Creek where Pinus ponderosa (ponderosa pine), western juniper, and mixed-conifer forests overtake herbaceous grasslands. Most land occupied by the Biggs herd is privately owned. Farmers can enroll fields in the Conservation Reserve Program and receive a yearly rental payment from the U.S. Department of Agriculture to remove land from agricultural production, thus reducing habitat loss (Farm Service Agency, 2023). Along with habitat degradation from the intrusion of invasive grasses and western juniper, Biggs mule deer are also negatively affected by U.S. Highway 97. From 2010 to 2022, the Oregon Department of Transportation (ODOT) recorded an average 30.5 deer-vehicle-collisions (DVCs; all local deer species) annually for a 77-mi (124-km) section of U.S. Highway 97 (ODOT, 2023). These mapping layers show the location of the annual ranges for mule deer (Odocoileus hemionus) in the Biggs population in Oregon. They were developed from 168 annual sequences collected from a sample size of 52 animals comprising GPS locations collected every 5-13 hours.

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  "geospatial"
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