Forage quality, road and stocking density influence the home range size of free-ranging beef cattle in the boreal forest

Abstract

This study explores area use of beef cows (Bos taurus) free ranging in boreal production forest of south-eastern Norway. The forests in this region serve multiple purposes, with forestry being the predominant industry. Understanding cattle’s area use is crucial for implementing resource management strategies that balance ecological and economic sustainability of these forests.The aim of the study was to examine how extrinsic factors (stocking density, forage quality, road presence, and herd size) and intrinsic factors (reproductive status and breed) influence variations in seasonal and weekly home range sizes of beef suckler cows. The study also investigated changes in home range size over time.The study was conducted over three summers, using GPS collars programmed to record positions at 5 and 10-minute intervals on 75 cows of early and late maturing beef cattle breeds. The cows were allowed to roam freely in two areas, one with a high stocking density and the other with a low stocking density.The seasonal home ranges were found to be surprisingly large, averaging 3,979 ± 344ha and 2,554 ± 246ha (± SE) in the low and high stocking density areas, respectively. Both seasonal and weekly home range sizes positively correlated with the proportion of poor-quality vegetation types within the home range. In the low stocking density area, road density was negatively related to seasonal and weekly home range size. Weekly home ranges were largest in the low stocking density area and showed a slight increase throughout the grazing season. No correlation was found between home range size and cattle breed or reproductive status.In line with previous studies on area use by wild herbivores, vegetation quality significantly influenced the size of their home range. Therefore, vegetation mapping in grazing areas is an essential tool for livestock management in non-arable areas. The difference of home range size between the study areas may be due to factors other than stocking density. This finding should be interpreted with caution, despite previous studies on wild herbivores confirming a negative correlation between population densities and home range size.Cows grazing in boreal forests use large areas and even larger when released to areas with poor forage quality, few roads and small stocking densities. This entails considerable movement throughout the grazing season, spanning across numerous habitats. This extensive area use can pose challenges for other stakeholders in the boreal forest and complicate the monitoring of cattle.