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Title: Diurnal activity of Rocky Mountain elk (Cervus elaphus) and beef cattle (Bos taurus) grazing a northeastern Oregon summer range

item Clark, Pat
item Ganskopp, David

Submitted to: American Society for Photogrammetry and Remote Sensing Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: 11/26/2007
Publication Date: 4/28/2008
Citation: Clark, P., Johnson, M.D., Ganskopp, D.C., Cook, R.C., Varva, M., Louhaichi, M., and Johnson, D.E. 2008. Diurnal activity of Rocky Mountain elk (Cervus elaphus) and beef cattle (Bos taurus) grazing a northeastern Oregon summer range. IN: 2008 Annual Conference Proceedings of the ASPRS. April 28 - May 2, 2008. Portland, OR. American Society for Photogrammetry and Remote Sensing. Abstract.

Interpretive Summary:

Technical Abstract: Rocky Mountain elk (Cervus elaphus) and beef cattle (Bos taurus) exist in a complex social environment that is marked by diurnal activities such as periods of foraging, ruminating, resting, and sheltering. Elk unlike cattle, must be continually alert to potential predators. We hypothesize that elk and cattle exhibit different innate diurnal behavioral strategies that could be quantified using GIS and GPS technologies. Our study described and compared the diurnal activities of elk and Cattle while grazing rangelands in northeastern Oregon. The study site consisted of two pastures (33.7 and 21.8 ha) that were split on the Starkey Experimental Forest and Range 34 km west of La Grande, Oregon (118.505225°W 45.242308°N). These pastures are composed of four plant communities: dry meadows, Douglas fir/oceanspray, Douglas fir elk sedge, and grand fir/pinegrass. Two herds of five elk and two herds of five cows each were observed in a randomized cross-over experimental design where each animal species occupied ½ of each study pasture for six days then was switched to the other half. This study was replicated twice (June 2007 and September 2007). Animals were directly observed during daylight hours and continuously monitored with GPS collars recording positional fixes each second. Animal paths were analyzed in a GIS environment. Diurnal spatial activity was measured as: distance traveled per day, time spent foraging, time spent stationary, travel velocities, and foraging dynamics. Foraging dynamics were extracted as velocity through various plant communities, time spent grazing in various communities, turning frequency at community boundaries, and path sinuosity.