Environmental constraints in the colonization sequence of roe deer (Capreolus capreolus Linnaeus, 1758) across the Iberian Mountains, Spain

Abstract

Aim This paper describes the dispersal process of roe deer (Capreolus capreolus Linnaeus, 1758) with respect to climatic factors, landscape characteristics and human activity. We hypothesized that environmental characteristics constrain the relative abundance and dispersal process of roe deer.Location The study was conducted in the Iberian Mountains, north-eastern Spain, during 1986-2000.Methods Roe deer colonization dates in the study area were obtained from a survey for large mammals and from direct interviews with the employees of the Fish and Game Agency. We used a 10 · 10 km UTM grid as the sampling unit (n ¼ 91). The relative abundance of roe deer was estimated by counting the number of pellet groups in line transects, which were representative of the habitat availability in the 10 · 10 km UTM grid. Climatic factors were obtained from meteorological stations placed near to the plot. Landscape structure indices, topography and human activity factors were obtained from digital maps using fragstats 3.3 and idrisi 32. We discarded a number of variables with no statistical significance and avoided multicollinearity by using Spearman rank correlation. Then, we used GLMz (with a multinomial error distribution and a logit link function) to analyse the influence of each variable considered in the dispersal process. Finally, GLMz (with a binomial error distribution and a logit link function) were used a posteriori to differentiate between the effects of the explanatory factors on a particular phase of the dispersal process. ResultsOur results indicate that proximity to a previously colonized grid significantly affected the global process of roe deer colonization. Independently of the proximity of the nearest population in the previous phase of colonization, our results also indicated that the dispersal process was influenced by precipitation and landscape structure, leading the species to colonize even apparently hostile places. Original nuclei of these populations occurred in territories with high and constant precipitation, and a landscape formed by mosaics of agricultural land with a high proportion of forests. During the expansion process, roe deer colonized territories with summer droughts, dominated by large agricultural patches and with few forest patches.Main conclusions These data support the working hypothesis that environmental characteristics constrain roe deer relative abundance and dispersal process through the Iberian Mountains. The location of the original nuclei of these populations probably had environmental conditions that were more favourable for the roe deer. Areas settled in the final phases of the dispersal process had low relative abundances of roe deer, and are likely to act mainly as dispersal corridors rather than being able to sustain viable populations themselves.

Changes in wild ungulate populations in Aragon, Spain between 2001 and 2010

“…Table 1. The number (and %) of 10 x 10-km grid blocks in which wild ungulate species occurred in Aragon, Spain, in the 2001-2005(Osuna et al 2006-2008 Today in Aragon, sympatry among wild ungulate species is common, however, in the mid-19th C., they occupied marginal, fragmented habitats in the mountains (Gortázar et al 2000). Wild boar has been present throughout Aragon since at least the end of the 20th Century (Gortázar et al 2000), and the range has remained stable.…”

“…The red deer population in the Pyrenees has two origins: reintroductions from Southern Iberia if a recognized geographical region and Central Europe (on the French Slope of the Pyrenees, see Marco et al 2011). In Aragon, the range of roe deer populations has increased significantly (Acevedo et al 2005), and there was no evidence of reintroductions since at least the end of the XX Century. In our study, roe deer were not detected in some grid blocks, probably because population densities were low.…”

“…The objective of this study was to update the information on the distribution of wild ungulates in Aragon by comparing two five-year periods, 2001-2005(Osuna et al 2006-08) and 2006-2010 …”

Situación de las poblaciones de corzo andaluz (Capreolus capreolus) en las sierras occidentales de Málaga

“…Los estudios disponibles que tratan el uso del hábitat por parte del corzo (Aragón et al 1995a, San José et al 1997, Virgós & Tellería 1998, Acevedo et al 2005, López-Martín et al 2009, Duarte et al 2010a, 2010b considerado tradicionalmente tres tipos de factores ambientales: topográficos-climáticos, vegetación y usos de suelo y antropogénicos. Cada factor contribuye en su medida a modelizar el hábitat utilizado por los corzos, pero es la vegetación disponible la que parece tener mayor peso en territorios pequeños, donde el clima y el factor humano son más homogéneos.…”

“…Se ha constatado que la especie ocupa, además de áreas forestales, muchos tipos de hábitats diferentes, estando presente en dehesas, pastizales y ecotonos forestales próximos a medios agrícolas y humanizados (Tellería & Virgós 1997, MateosQuesada 2005b, Duarte et al 2009). En el proceso de recolonización el corzo se ha valido de corredores con hábitats subóptimos en los que se afincan poblaciones poco abundantes (Acevedo et al 2005). La plasticidad ecológica de la especie le ha permitido instalarse incluso en zonas con cierto grado de humanización.…”