Changes in management shape the spatial ecology of wild ponies in relation to habitat conservation
摘要
Large herbivores are key regulators of open habitats across the world. Free roaming ponies have a prominent ecological role in many Atlantic landscapes, where different habitats with conservation interest are linked to ponies’ occurrence. The traditional management of wild ponies, which implies minimum human intervention, is declining in Galicia, NW Spain. Changes in the management regimes include the confinement of ponies in fenced areas, the use of improved pastures (IPs) and rotation between fields. Indirect effects of these changes are expected on the ecological condition of important habitats for conservation such as dry and wet heathlands and bogs. We studied social structure, spatial ecology and habitat use in 29 mares fitted with global positioning system (GPS) collars and field observations in two areas of Galicia dominated by wet heaths and blanket bogs (Xistral), and dry heaths (Sabucedo). We used spatial location and field observations to identify each band, and calculated band size, sex ratio, home range (HR) and core area size and overlap, as well as habitat use. We accounted for differences by adjusting Generalized Linear Models (GLMs) for these variables as functions of management type: free roaming vs. rotation, use of IPs, fencing, and available ranging area. Larger bands were found in smaller commons, with fencing and rotation management. Home ranges, but not core area, varied as a function of the available ranging area. Band overlap was higher in fenced areas with rotation management. Increasing management may concentrate grazing pressure by reducing HRs and increasing spatial overlap between bands, which may have a long-term effect on habitat quality and conservation.