Assessing landscape resistance to roe deer dispersal using fuzzy set theory and multicriteria analysis: a case study in Central Spain

Abstract

The central Iberian Peninsula has one of the highest densities of roe deer populations in Spain. A new motorway is planned to pass through the middle of the distribution of roe deer, thus making it necessary to conduct a connectivity analysis. A map of resistance to roe deer dispersal movements was obtained based on the literature and expert judgment. Three factors were selected: land use (defined by the ability to hide movements, food source, and degree of naturalness), landforms, and influence due to proximity to elements that increase (such as roads and urban areas) or decrease (water resources and proximity to optimal habitat patches) resistance at the local level. Different combinations of factors derived using the analytical hierarchy and fuzzy logic processes were analysed and compared with the real distribution of the species. More realistic resistance (cost) values were obtained for gamma values close to 0.9. This highlights the greater predominance of the fuzzy sum over the fuzzy product in modelling the cost surface. Better results were obtained in scenarios where the predominant factors were either land use and landforms or land use and proximity to humanmodified areas. This indicates that roe deer will readily range far from their optimal patches if the land use provides partial cover. These movements appear to be conditioned by steep terrain. Our case study offers a good example of building a cost resistance matrix to help locate areas where the expansion of the species may be curbed or encouraged.

Ungulates in the city: light pollution and open habitats predict the probability of roe deer occurring in an urban environment

“…Ungulates are animals which have only quite recently begun to colonize urban areas, but so far with rather moderate success (Kilpatrick and Spohr 2000;Acevedo et al 2005;Underwood and Kilheffer 2016). In general, large mammalian herbivores avoid strongly urbanized areas (Underwood and Kilheffer 2016;Loro et al 2016). Small populations of ungulates colonize mainly suburban areas (McCarthy et al 1996;Kilpatrick and Spohr 2000;Mattila and Hadjigeorgiou 2015;Loro et al 2016), with only small numbers of individuals entering densely built-up areas (Warren 2011).…”

“…In general, large mammalian herbivores avoid strongly urbanized areas (Underwood and Kilheffer 2016;Loro et al 2016). Small populations of ungulates colonize mainly suburban areas (McCarthy et al 1996;Kilpatrick and Spohr 2000;Mattila and Hadjigeorgiou 2015;Loro et al 2016), with only small numbers of individuals entering densely built-up areas (Warren 2011). Moreover, the colonization of suburbs by ungulates is often of a transitional nature, resulting from overabundances in adjacent areas (Warren 2011;Mattila and Hadjigeorgiou 2015).…”

“…Human habitations pose a further threat to land animals (McCarthy et al 1996;Hewison et al 2001;Underwood and Kilheffer 2016): not only do they cause their habitats to shrink (Underwood and Kilheffer 2016;Loro et al 2016), there is increased pressure on the part of humans and their dogs, which frequently flush out wild animals, raising stress levels and inflicting energy losses in the latter (Reimoser 2012;Padié et al 2015). The encroachment of ungulates on to land used by humans often leads to conflicts (Putman and Moore 1998;Warren 2011;Mattila and Hadjigeorgiou 2015): as a consequence, habitats may be fenced off (Boone and Hobbs 2004;Harrington and Conover 2006) and the animals culled (Brown et al 2000;Warren 2011).…”

“…One of the ecologically more flexible ungulate species is the roe deer Capreolus capreolus, which inhabits woodlands and open country, and also a mosaic of both (Putman 1986;Morellet et al 2011;Ewald et al 2014). The habitats utilized by roe deer are often situated in a landscape matrix that includes areas transformed by humans to varying extents (McCarthy et al 1996;Acevedo et al 2005;Torres et al 2011;Loro et al 2016). The results of studies done to date on the effects of urbanization on roe deer are equivocal: although this species seems to avoid areas with a moderate degree of urbanization (Hewison et al 2001;Loro et al 2016), it may occasionally prefer the proximity of thinly urbanized areas (Torres et al 2011).…”

“…The habitats utilized by roe deer are often situated in a landscape matrix that includes areas transformed by humans to varying extents (McCarthy et al 1996;Acevedo et al 2005;Torres et al 2011;Loro et al 2016). The results of studies done to date on the effects of urbanization on roe deer are equivocal: although this species seems to avoid areas with a moderate degree of urbanization (Hewison et al 2001;Loro et al 2016), it may occasionally prefer the proximity of thinly urbanized areas (Torres et al 2011). The issue of roe deer encroaching into strongly urbanized areas has not been explored as yet.…”