Date of Award

2020

Document Type

Doctoral Thesis

Degree Name

Doctor of Philosophy

Department

Biological and Pharmaceutical Science

First Advisor

Dr Gemma Therese Higgins

Second Advisor

Dr Geraldine Twamley-Stein

Abstract

Marrying conservation objectives with farming practices is a challenging necessity in the current era of anthropogenically-driven biodiversity loss. Upland habitats created by traditional farming are havens for wildlife but face multiple threats, including overgrazing and abandonment. Extensive cattle farming in the uplands has been mooted as a useful conservation measure, but Irish evidence supporting this approach is lacking. This thesis examines home range, habitat preferences and activity budgets for Dexter cattle in an extensive upland setting in southwest Ireland. It investigates the effects of the grazing regime on EU-protected habitats and ground beetles. Free-ranging cattle grazed the site over three seasons from 2013-2015. Cattle were tracked by GPS to establish home range and habitat preferences. Direct observation compared activity budgets of upland and lowland herds. Kernel Density Estimation was used to develop a utilisation score. Vegetation and ground beetle sampling examined the impact of the grazing in relation to utilisation. Mean home range size was 122.7 ha. Wet heath constituted 46% of the home range; blanket bog, 23%; dry heath, 22%; wet grassland, 9%. Cattle showed significant preference for wet grassland and dry heath, and avoidance of blanket bog and wet heath. Activity budgets showed the upland herd spent significantly more time grazing than the lowland herd. Stocking rates were 0.17 LU.ha-1 for the whole study site, 0.12 LU.ha-1 in wet heath, 0.20 LU.ha-1 in dry heath, 0.14 LU.ha-1 in blanket bog, and 0.42 LU.ha-1 in wet grassland. At these densities the conservation status of the Annex I habitats was maintained or enhanced. Utilisation had a positive influence on plant species richness and community evenness, however variation between grazed and ungrazed plots was not significant. Beetle species richness did not vary between treatments. The abundance of large wingless ground beetles was consistently depressed across all grazed areas. Conservation grazing prescriptions should account for availability and spatial distribution of habiat patches, preference of animals, and length of grazing season.

Access Level

info:eu-repo/semantics/openAccess

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