Seasonal and Diurnal Vegetation Cover Preferences by Beef Cattle While Grazing Native Aspen Parkland Rangeland

ABSTRACT Cattle vegetation type selection is important for optimizing the use and conservation of pastures, including in response to seasonal foraging conditions. This study examined vegetation cover type preferences by beef cattle while grazing over three growing seasons (2021–2023) in the Aspen Parkland, a vegetationally diverse transition region between prairie grasslands and boreal forests. Using global navigation satellite system tracking collars affixed to cattle and an advanced vegetation map, we quantified cattle selection of vegetation under varying conditions using Ivlev’s Electivity Index across multiple temporal scales, including seasons (summer vs. fall), grazing periods within individual paddocks, and diurnal periods. No differences in vegetation selection were evident between cows and heifers ( P > 0.05), indicating age and reproductive status did not regulate vegetation type occupancy. Cattle exhibited distinct preference and avoidance patterns for vegetation types, and these changed over time. Seasonal shifts in vegetation preference occurred, with cattle selecting primarily wetlands and upland grasslands in summer while avoiding forests and closed shrublands. Cattle occupancy of open shrublands increased during fall, with less avoidance of forests and decreased use of grasslands. While forage biomass and quality interacted with vegetation type within a grazing period to alter electivity, these results were inconsistent in direction and magnitude, suggesting the factors mediating vegetation use included foraging opportunities and other benefits. Diurnal changes in vegetation selection also occurred, with cattle increasing their occupancy of grassland at night and forests during the day. This study provides novel insight on cattle ecology and behavior within Parkland rangelands and highlights the need to maintain a diverse landscape with a variety of vegetation types to meet cattle needs throughout the grazing season.