High temporal resolution photography for observing riparian area use and grazing behavior

Authors: Nichols, Mary; RUYLE, G.B. - University Of Arizona; DILLE, P. - Carnegie Mellon University

Submitted to: Rangeland Ecology and Management
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/4/2017
Publication Date: 4/1/2017
Citation: Nichols, M.H., Ruyle, G., Dille, P. 2017. High temporal resolution photography for observing riparian area use and grazing behavior. Rangeland Ecology and Management. 70(4):418-421. https://doi.org/10.1016/j.rama.2017.01.001.
DOI: https://doi.org/10.1016/j.rama.2017.01.001

Interpretive Summary: Although riparian areas are estimated to comprise less than 2% of the western US land area, they are primary water sources that provide critical habitat for wildlife and are important to people for recreation and open space. In addition, many riparian areas within both privately owned and leased public lands are grazed by livestock. Many riparian areas within public lands are managed with the goal of maintaining proper function and condition by addressing forage use by permitted livestock. Forage use can be assessed using traditional vegetation monitoring techniques, but where livestock share the use of forage with wildlife is not possible to know which animals are foraging. We set up a time-lapse camera on a 2.4 hectare riparian site within the Apache-Sitgreaves National Forest in northeastern Arizona, USA and took pictures every 30 seconds during periods of 1) unrestricted access, 2) prescribed cattle use, and 3) restricted access via electric fence. Elk exhibited the unique behavior of standing in and traveling within the stream channel while grazing and tended to graze and lie in close proximity to the channel. Cattle drank from, but typically did not enter the stream channel and tended to lie away from the channel. Recreational use by people had the distinct impact of dispersing elk from the riparian corridor. Time-lapse photography is a useful tool for documenting specific riparian area use by cattle and elk, and people.

Technical Abstract: In 2014, a 2.4 hectare site within the Apache-Sitgreaves National Forest in northeastern Arizona, USA was selected to characterize temporal and spatial patterns of riparian area use. Three consecutive 30, 8, and 46 day time periods representing 1) unrestricted access, 2) prescribed cattle use, and 3) restricted access via electric fence were characterized. Photographs were taken every 30 seconds during the first two time periods, and every three minutes thereafter. Images were evaluated to characterize individual animal and herd movement and behavior in the riparian area and adjacent uplands. In addition, grazed and ungrazed vegetation stubble height data and bank disturbance data were collected. Image analysis indicated that elk (Cervus elaphus nelsoni) occupied the area an average of 17.5% of daylight hours during 2 days of occupation prior to cattle presence and cattle occupied an average of 19.4% of daylight hours during 8 days of occupation. Elk and cattle exhibited statistically significant (p=0.01) differences in grazing distance from the stream channel. Elk exhibited the unique behavior of standing in and traveling within the stream channel while grazing and tended to graze and lie in close proximity to the channel. Cattle drank from, but typically did not enter the stream channel and tended to lie away from the channel. Recreational use by people had the distinct impact of dispersing elk from the riparian corridor. Throughout the grazing period measured stubble heights were greater than the minimum residual heights often suggested as general riparian grazing management guidelines, and access restriction allowed for plant regrowth.