Measures of daily distribution patterns of cow calf pairs using global positioning systems on both cows and calves

TitleMeasures of daily distribution patterns of cow calf pairs using global positioning systems on both cows and calves
Publication TypeConference Paper
Year of Publication2008
AuthorsWesley R.L., Cibils AF, Pollak E.R., Cox S.H., Mulliniks T., Petersen M.K., Fredrickson E.L.
Conference NameSociety for Range Mangement
Date PublishedJanuary 26, 2008
Accession NumberJRN2525
ARIS Log Number215288
Keywordsabstract, abstracts, GPS collars, pinyon juniper

GPS collars were used to describe the daily distribution patterns of cows and their calves from 18 to 60 days postpartum on pinyon juniper-shortgrass rangeland in central New Mexico. Eighteen, 3 year old cows and their calves were fitted weekly with GPS collars for seven consecutive weeks. Twenty days with cow calf pair location data for at least 48 consecutive hours were randomly selected. Daily area explored was estimated using the area of the 90% volume contour predicted with Kernel Analysis in the animal movements extension of ArcVeiw GIS 3.3. Cows daily distance traveled ranged from 2.7 to 6.2 km and they explored between 4.5 and 28.5ha day-1. Calves traveled between 2.2 and 6.1 km day-1 while exploring areas ranging from 1.3 to 16.7ha, of which an average of 5.5 ± 2.9ha overlapped with the area explored by its mother. Neither daily distance traveled nor area explored by the cow were correlated with calf age, but calves tended to travel longer distances and explore larger areas with increasing age (r=0.37, P= 0.10 and r=0.38, P=0.10, respectively). Cows visited water 85%, and calves 15%, of the days sampled. Average distance from water was 0.8 ± 0.21 km for cows and calves and was positively correlated for both with calf age (r=0.53, P=0.02 and r =0.57, P=0.01 respectively), as was maximum distance traveled from water (r=0.36, P=0.11, and r=0.47, P=0.03, respectively). Cows spent between 4.4 and 15.1 hours total, but never more than 8.3 hours in one event, farther than 100m away from their calves in any 24 hour period. Maximum distance between a calf and its mother was positively correlated with age (r=.50, P=0.02). Search patterns of cows (ratio between daily distance traveled and daily area explored) became considerably more concentrated when they remained in the proximity of their calves.