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Abstract. Recent climate change is frequently invoked as the cause of changes in phenology and distances of migration. Birds are expected to reduce the length of migration in response to milder climatic conditions, and during the last years, there are a growing number of records of European long-distance migrants wintering in the Iberian Peninsula. For this reason, we have used in this study the available ringing and recoveries data for the Eurasian Reed Warbler in the Iberian Peninsula during winter, spanning 1959–2015. We show that during the last decades this insectivorous species occurs regularly during winter in South-western Europe, which could be related to the recent climate change. Some Iberian birds wintered in breeding areas, or nearby, which could indicate a potential process of sedentarization, while Eurasian Reed Warblers from Central and Northern Europe shortened the migration distance avoiding the crossing to Africa. Iberian wintering grounds seemed to be related to the origin of the birds, with British Eurasian Reed Warblers staying more northerly that individuals from Central Europe, and Eastern birds showing a tendency to winter on the Mediterranean coast. Our results support the contemporary trend of migrants overwintering at higher latitudes. Despite the considerable increase of wintering records during the last decades, we cannot confirm a real expansion because there has been an increase in ringing activity over the study period. Nevertheless, the presence of this species has become consistent during winter in well-sampled areas where it was absent in the past. With warmer winters we expect changes in the migratory system, and also an increase in frequency of long-distance migrants that avoid the crossing of the Mediterranean and the Sahara desert to remain in southern Europe during cold months. [ABSTRACT FROM AUTHOR]

Aim A striking case of mitochondrial DNA (mt DNA) introgression occurs in the Iberian Peninsula: the mt DNA of Lepus timidus, a species that inhabited this territory during the Last Glacial Maximum ( LGM), is almost fixed in the Iberian range of Lepus europaeus, is very frequent in the northern half of Iberia within Lepus granatensis, and is fixed in Lepus castroviejoi. Here, we used a transdisciplinary approach to understand the ecological drivers of the distribution of this introgressed mt DNA in the Iberian hare species. Location Europe, with an emphasis on the Iberian Peninsula. Methods First, we modelled the climatic niche of L. timidus to predict the favourability for the species during the LGM. Second, we gathered data regarding L. timidus mt DNA introgression for 1137 individuals (139 populations) from the Iberian Peninsula. We tested whether the climatic favourability for L. timidus during the LGM reflects the frequency of the introgressed mt DNA in the carrier hare populations. Results The climatic favourability for the LGM is positively related to the presence of individuals with L. timidus mt DNA, and discriminates better than by chance between individuals with and without this lineage. At the population level, the favourability values relate to the observed frequencies of mt DNA introgression and discriminate between populations with and without L. timidus mt DNA. Main conclusions The results suggest that the geographical distribution of L. timidus mt DNA introgression is linked to L. timidus distribution in Iberia during the LGM. Our study helps to improve our understanding of the role of climate in the reticulated evolutionary history of hares, and is a first step towards understanding the ecological impact of mt DNA introgression on Iberian hares. [ABSTRACT FROM AUTHOR]

The rapid ecological shifts that are occurring due to climate change present major challenges for managers and policymakers and, therefore, are one of the main concerns for environmental modelers and evolutionary biologists. Species distribution models ( SDM) are appropriate tools for assessing the relationship between species distribution and environmental conditions, so being customarily used to forecast the biogeographical response of species to climate change. A serious limitation of species distribution models when forecasting the effects of climate change is that they normally assume that species behavior and climatic tolerances will remain constant through time. In this study, we propose a new methodology, based on fuzzy logic, useful for incorporating the potential capacity of species to adapt to new conditions into species distribution models. Our results demonstrate that it is possible to include different behavioral responses of species when predicting the effects of climate change on species distribution. Favorability models offered in this study show two extremes: one considering that the species will not modify its present behavior, and another assuming that the species will take full advantage of the possibilities offered by an increase in environmental favorability. This methodology may mean a more realistic approach to the assessment of the consequences of global change on species' distribution and conservation. Overlooking the potential of species' phenotypical plasticity may under- or overestimate the predicted response of species to changes in environmental drivers and its effects on species distribution. Using this approach, we could reinforce the science behind conservation planning in the current situation of rapid climate change. [ABSTRACT FROM AUTHOR]

Distribution models are used increasingly for species conservation assessments over extensive areas, but the spatial resolution of the modeled data and, consequently, of the predictions generated directly from these models are usually too coarse for local conservation applications. Comprehensive distribution data at finer spatial resolution, however, require a level of sampling that is impractical for most species and regions. Models can be downscaled to predict distribution at finer resolutions, but this increases uncertainty because the predictive ability of models is not necessarily consistent beyond their original scale. We analyzed the performance of downscaled, previously published models of environmental favorability (a generalized linear modeling technique) for a restricted endemic insectivore, the Iberian desman (Galemys pyrenaicus ), and a more widespread carnivore, the Eurasian otter (Lutra lutra ), in the Iberian Peninsula. The models, built from presence-absence data at 10 × 10 km resolution, were extrapolated to a resolution 100 times finer (1 × 1 km). We compared downscaled predictions of environmental quality for the two species with published data on local observations and on important conservation sites proposed by experts. Predictions were significantly related to observed presence or absence of species and to expert selection of sampling sites and important conservation sites. Our results suggest the potential usefulness of downscaled projections of environmental quality as a proxy for expensive and time-consuming field studies when the field studies are not feasible. This method may be valid for other similar species if coarse-resolution distribution data are available to define high-quality areas at a scale that is practical for the application of concrete conservation measures. [ABSTRACT FROM AUTHOR]

Transferring distribution models between different geographical areas may be problematic, as the performance of models outside their original scope is hard to predict. A modelling procedure is needed that gets the gist of the environmental descriptors of a distribution area, without either overfitting to the training data or overestimating the species’ distribution potential. We tested the transferability power of the favourability function, a generalized linear model, on the distribution of the Iberian desman (Galemys pyrenaicus) in the Iberian territories of Portugal and Spain. We also tested the effects of two of the main potential constraints on model transferability: the analysed ranges of the predictor variables, and the completeness of the species distribution data. We modelled 10km×10km presence/absence data from Portugal and Spain separately, extrapolated each model to the other country, and compared predictions with observations. The Spanish model, despite arguably containing more false absences, showed good predictive ability in Portugal. The Portuguese model, whose predictors ranged between only a subset of the values observed in Spain, overestimated desman distribution when transferred. We discuss possible reasons for this differential model behaviour, and highlight the importance of this kind of models for prediction and conservation applications. [Copyright &y& Elsevier]

We used the results of the Spanish Otter Survey of 1994–1996, a Geographic Information System and stepwise multiple logistic regression to model otter presence/absence data in the continental Spanish UTM 10×10-km squares. Geographic situation, indicators of human activity such as highways and major urban centers, and environmental variables related with productivity, water availability, altitude, and environmental energy were included in a logistic model that correctly classified about 73% of otter presences and absences. We extrapolated the model to the adjacent territory of Portugal, and increased the model''s spatial resolution by extrapolating it to 1×1-km squares in the whole Iberian Peninsula. The model turned out to be rather flexible, predicting, for instance, the species to be very restricted to the courses of rivers in some areas, and more widespread in others. This allowed us to determine areas where otter populations may be more vulnerable to habitat changes or harmful human interventions. [Copyright &y& Elsevier]