Spatial structure of roe deer populations: towards defining management units at a landscape scale

Abstract

Summary 1.A crucial question in wildlife management concerns the definition of ecologically meaningful management units. Management action needs to be co-ordinated at the appropriate spatial scale. There are few practical tools for delimiting pertinent management units for large mammals such as ungulates. 2. Previous work has favoured a molecular approach to determine genetically distinct units, but this may be too costly for routine management. In addition, recent studies have revealed fine-scale heterogeneity in population dynamics of free-ranging ungulates in relation to environmental variability. 3. We combined spatial analysis of environmental heterogeneity (vegetation cover, topography and climate), animal morphology (jaw length) and genetic structure (microsatellites) to define biologically meaningful population units for roe deer Capreolus capreolus in the Belluno province, north-eastern Italy. Jaw length is a sensitive measure of density-dependence and a good proxy for spatial and temporal variation in roe deer population growth. 4. Spatial analysis of environmental variables suggested that the study area should be divided into two, or possibly four, biogeographical regions in relation to variation in altitude and habitat type. There was significant spatial variability in jaw length across the province that clustered into two main regions (with shorter jaws in the north compared with the south), which matched the previously defined biogeographical regions. This spatial structuring was also supported by microsatellite analysis, which revealed two genetically distinct populations, one in the north and one in the south. 5. Synthesis and applications . A multiparameter approach, combining environmental information with data on indices of density-dependence such as jaw length, could be extremely useful for defining ecologically meaningful management units. Indeed, monitoring spatial and temporal variation in jaw length could provide deer managers with a simple way to index population structure and fluctuations in time and space.

Is the abandonment of traditional livestock farming systems the main driver of mountain landscape change in Alpine areas?

“…The two geographical units identified in this study using landscape descriptors and indicators of livestock systems are similar to those obtained in another study that used only landscape features (Zannése et al, 2006). This similarity highlights how different landscapes might shape the evolution of livestock farming systems.…”

“…Belluno is a heterogeneous province, with a wide variation in morphology, land use (Zannése et al, 2006), farm density and other characteristics (Sturaro et al, 2009). Therefore, a preliminary cluster analysis was performed on the 69 municipalities to identify homogeneous geographical units.…”

The demographic drivers of local population dynamics in two rare migratory birds

“…Identification of the spatial scale at which populations are influenced is important for defining informed conservation management units and implementing appropriate action (Baillie et al 2000;Zannèse et al 2006;Sirami et al 2008). Identification of the main demographic processes involved in local population dynamics can help to identify the spatial scale at which population dynamics operate.…”

Forest edge creates small‐scale variation in reproductive rate of sika deer

“…Recent studies have shown that deer populations have spatial structures comprising units that differ in densities and vital rates (Coulson et al 1997;Focardi et al 2002;Pettorelli et al 2003;Zannese et al 2006), most of which are formed by heterogeneous landscape structure. One of the important elements causing forest heterogeneity is the forest edges that abut clearcuts, farmlands, and roads, which provides abundant and high-quality foliage (e.g., Lyon and Jensen 1980;Alverson et al 1988;Decalesta 1997).…”