Social and Environmental Factors Influence Cattle Distribution on Rangeland
Applied Animal Behaviour Science
Larry D. Howery, Frederick D. Provenza, Roger E. Banner, Cody B. Scott, Social and environmental factors influence cattle distribution on rangeland, Applied Animal Behaviour Science, Volume 55, Issues 3-4, January 1998, Pages 231-244.
We determined the cattle distribution patterns of dams (and foster dams) and their offspring while grazing a 1030 ha (about 3 km by 5 km) allotment during the summers of 1990–1993. Our primary objective in this 4-year field study was to determine whether yearling and adult offspring (and foster offspring) would return to the initial locations and associated habitat types that they were exposed to by their dams (or foster dams) early in life. We observed the dams' offspring for four consecutive summers (1990–1993) and the foster-dams' offspring for 3 consecutive summers (1991–1993). Cross-fostering was conducted to learn the relative importance of natural dams vs. foster dams as social models in influencing distribution patterns of offspring. Offspring were reared mostly in two different locations on the allotment by their dams or foster dams. Centroid analyses indicated that offspring in all 4 groups remained near the general location where they were reared as calves when they returned to the allotment as older animals (mean 0.5 to 1.2 km from dams' or foster dams' centroid). Peers apparently attenuated the dams' (and foster dams') influence on location and habitat use when offspring were yearlings. The effect of peers was manifested by an increase in distance from dams' or foster dams' centroid, and by a higher association index among yearlings, both of which reflected the collective experiences of offspring in the peer groups. Drought weakened the dams' and foster dams' influence on location and habitat use as water became scarce near their centroids, but drought amplified the dams' and foster dams' influence when water was not limited near their centroids. By the final year of the study, offspring in 3 of the 4 groups monitored were within 0.7 km from the dams' or foster dams' centroid (offspring in the fourth group were within 1.1 km from the foster dams' centroid). Collectively, our results suggest that experiences early in life affected cattle distribution, and that distribution at any point in time was a ‘snapshot’ of ongoing behavioral changes that were developing according to each individual's antecedent experiences and current environmental and social conditions. These results support the ‘working hypotheses’ that herding, selective culling, and water and shade development are important management techniques that can enhance dispersion and decrease use of sensitive areas on rangelands (e.g., riparian areas).