Resource selection by hill sheep: direct flock observations versus gps tracking

Abstract

Uplands and peatlands are of international ecological importance and heavy grazing pressure has been implicated in a decline in their condition. Therefore, a better understanding of grazer behaviour could aid the design of conservation strategies. The objective of this study was to test whether the same resource selection results were obtained from direct flock observations as simultaneously-run GPS tracking studies. Direct flock observations were conducted on 50 sampling days, June 2004-July 2005. Habitat, habitat condition and grazing lawn frequency maps were produced. Resource use and availability were estimated using range analysis and GIS, and resource selection was analysed using weighted compositional analysis. Flock distribution was uneven with a mean of 0.0-8.9 sheep/ha observed based on a 1 ha grid system. Habitat selection based on direct observations varied seasonally with acid grassland-related habitats selected most in spring, summer and autumn, and wet heath and blanket bog selected most in winter. Moderately damaged areas and grid squares containing numerous/extensive grazing lawns were consistently selected most (P<0.05). Resource selection findings based on direct flock observations were consistent with those obtained using detailed GPS tracking data from fewer individuals. Resource management recommendations are discussed.