Prescribed fire effects on activity and movement of cattle in mesic sagebrush steppe

Authors: Clark, Pat; NIELSON, RYAN - Nature West, Inc; LEE, JAECHOUL - Boise State University; KO, KYUNKDUK - Boise State University; JOHNSON, DOUGLAS - Oregon State University; Ganskopp, David; CHIGBROW, JOE - University Of Idaho; Pierson Jr, Frederick; Hardegree, Stuart

Submitted to: Rangeland Ecology and Management
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/17/2016
Publication Date: 1/18/2017
Citation: Clark, P., Nielson, R.M., Lee, J., Ko, K., Johnson, D.E., Ganskopp, D.C., Chigbrow, J., Pierson, F.B., Hardegree, S.P. 2017. Prescribed fire effects on activity and movement of cattle in mesic sagebrush steppe. Rangeland Ecology and Management. 70(4):437-447. doi: 10.1016/j.rama.2016.11.004.

Interpretive Summary: While the efficacy of prescribed fire as a tool for managing grazing animal distribution and diet quality has received much study, prescribed-fire effects on the activity budgets and movement path characteristics of grazing animals remain largely unknown, particularly, in the mesic sagebrush steppe. Mature, lactating beef cows grazing mesic sagebrush steppe within two study areas located in the Owyhee Mountains of southwestern Idaho, USA were tracked with GPS collars for 2 years before and 5 years after fall prescribed fires were applied. Generally, cattle in burned sites following fire treatments tended to increase their foraging activity budgets, bout durations, bout counts, and path lengths and tortuosities relative to cattle in these sites during the prefire period and to cattle in unburned sites postfire. These findings suggest livestock producers can use prescribed fire in mesic sagebrush steppe as a means to create opportunities for cattle to improve foraging efficiency which, ultimately, would promote increased rates of weight gain, and other measures of productivity.

Technical Abstract: Prescribed fire has long been used worldwide for livestock and wildlife management. The efficacy of prescribed fire for manipulating grazing animal distribution and diet quality has been well studied in many ecosystems but prescribed-fire effects on activity budgets and movement path characteristics of grazing animals remain largely unknown. We evaluated whether prescribed-fire treatments in mesic sagebrush steppe affect cattle behaviors which could influence foraging efficiency and, ultimately, impact animal productivity. Mature, lactating beef cows grazing within two study areas located in the Owyhee Mountains of southwestern Idaho, USA were tracked with GPS collars for 2 years before and up to5 years after fall prescribed fires. Acquired GPS data were classified into stationary, foraging, and traveling activity types based on movement distance and velocity thresholds. Cattle activity budgets, bout durations, bout counts, velocities, and path lengths, steepnesses, and tortuosities were contrasted between burned and unburned sites within the study areas. After fire, cattle in burned sites tended to increase their foraging activity budgets, bout durations, bout counts, and path lengths and tortuosities relative to prefire and cattle in unburned sites. Fire did not affect the steepness of cattle foraging paths. Prescribed fire in mesic sagebrush steppe can be used to create opportunities for cattle to improve foraging efficiency by altering their activity budgets and movement path characteristics. Any consequent improvements in foraging efficiency could, in turn, promote increased rates of weight gain, better body condition, enhanced reproductive success, and ultimately, more pounds of beef for market.