Habitat selection by grazing animals in heterogeneous environments: The case of hill sheep in western Ireland

Uplands and peatlands are of high conservation importance and, while grazing animals are a key management tool for conservation, grazing-related damage can easily occur. Damage to European uplands is most notable in Britain and Ireland, where Scottish Blackface is the dominant hill sheep breed. Therefore, if conservation strategies that address concerns of grazing-related damage are to be strengthened, the Scottish Blackface is a good subject and a better understanding of their resource use would be advantageous. While previous habitat selection studies of hill sheep have depended on direct observation, this particular study uses Global Positioning System tracking collars to determine ewe locations. The study site is on a mountainside in western Ireland that is dominated by blanket bog (52.8%) and wet heath (35.3%). Habitat mapping and ewe range and resource selection analyses indicated that habitat selection was significant (P<0.05), typically acid grassland is selected most followed by wet heath, with blanket bog habitats selected least. Seasonal variation in habitat selection was also evident. These results (1) corroborate the findings of previous work elsewhere on plant community/habitat selection and (2) provide additional information that can be used to strengthen existing or new hill grazing management models that are used to aid decision-making. In particular, management plans should take into consideration the availability (both in terms of total area and connectivity) of the preferred sheep habitats and specifically consider grazing pressure in and between those habitats.