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Assessing the response of exploited marine populations in a context of rapid climate change: the case of blackspot seabream from the Strait of Gibraltar.— There is a growing concern over the decline of fisheries and the possibility of the decline becoming worse due to climate change. Studies on small–scale fisheries could help to improve our understanding of the effect of climate on the ecology of exploited stocks. The Strait of Gibraltar is an important fishery ground for artisanal fleets. In this area, b lackspot seabream ( Pagellus bogaraveo ) is the main species targeted by artisanal fisheries in view of its relevance in landed weight. The aims of this study were to explore the possible effects of two atmospheric oscillations, the North Atlantic Oscillation (NAO) and the Arctic Oscillation (AO), on the capture of blackspot seabream in the Strait of Gibraltar, to determine their association with oceanographic conditions, and to improve our knowledge about the possible effects of climate change on fisheries ecology so that fishery management can be improved. We used two types of data from different sources: (i) landings per unit of effort reported from a second working group between Morocco and Spain on Pagellus bogaraveo in the Gibraltar Strait area, for the period 1983–2011 , and (ii) the recorded blackspot seabream landings obtained from the annual fisheries statistics published by the Junta de Andalucía (Andalusian Regional Government). Our results indicate that the long–term landing of blackspot seabream in the Strait of Gibraltar is closely associated with atmospheric oscillations. Thus, prolonged periods of positive trends in the NAO and AO could favour high fishery yields. In contrast, negative trends in NAO and AO could drastically reduce yield.

We assessed the vulnerability of the native Mediterranean pond turtle to encroachment by the invasive red-eared slider in southern Spain. We first obtained an ecogeographical favourability model for the Mediterranean pond turtle. We then modelled the presence/absence of the red-eared slider in the Mediterranean pond turtle range and obtained an encroachment favourability model. We also obtained a favourability model for the red-eared slider using the ecogeographical favourability for the Mediterranean pond turtle as a predictor. When favourability for the Mediterranean pond turtle was high, favourability for the red-eared slider was low, suggesting that in these areas the Mediterranean pond turtle may resist encroachment by the red-eared slider. We also calculated favourability overlap between the two species, which is their simultaneous favourability. Grids with low overlap had higher favourability values for the Mediterranean pond turtle and, consequently, were of lesser conservation concern. A few grids had high values for both species, being potentially suitable for coexistence. Grids with intermediate overlap had similar intermediate favourability values for both species and were therefore areas where the Mediterranean pond turtle was more vulnerable to encroachment by the red-eared slider. We mapped the favourability overlap to provide a map of vulnerability of the Mediterranean pond turtle to encroachment by the red-eared slider.

[Aim]: Lepus castroviejoi and Lepus corsicanus are sister species with allopatric distributions that share extensive phenotypic and genetic variation. Under the framework of niche conservatism, we assessed whether these species have similar ecological niches, which could provide insights into their mode of divergence, conservation, and taxonomic status. [Location]: The distribution range of L. castroviejoi in the northern Iberian Peninsula, and that of L. corsicanus in mainland Italy and Sicily. [Methods]: We developed spatially explicit ecological models to characterize the niches of the two species by modelling them separately and together. Individual models were transferred to the territory of the sister species to explore their niche relationships. Predictions were assessed for discrimination and calibration in a cross-assessment procedure. [Results]: The model trained with L. castroviejoi was not able to predict the range of L. corsicanus, whereas the model trained with L. corsicanus was able to discriminate the L. castroviejoi distribution better than by chance alone (AUC = 0.814), although the reliability of the predictions was limited. The model trained with L. corsicanus in Italy's mainland (excluding the range in Sicily), however, discriminated L. castroviejoi presences/absences (AUC = 0.788) and accurately predicted its probability of occurrence. Furthermore, a well-calibrated model, which was able to discriminate the species distributions (L. castroviejoi, AUC = 0.828; L. corsicanus, AUC = 0.956), was obtained when the species were considered together. [Main conclusions]: Our results suggest that L. castroviejoi and L. corsicanus share extensive niche properties, which reinforces their possible conspecific status. The ecological niche of their ancestor may have resembled the present occupied niche of L. corsicanus in mainland Italy, given that this model was able to accurately predict the distribution range of both species. Finally, ecological evidence s

Analysis of the effect of atmospheric oscillations on physical condition of pre–reproductive bluefin tuna from the Strait of Gibraltar .— The aim of this study was to explore the possible effects of atmospheric oscillations: North Atlantic Oscillation (NAO) and Arctic Oscillation (AO), on the physical condition of bluefin tuna ( Thunnus thynnus ). We estimated a fitness ratio from 3,501 pairs of length–weight data based on bluefin tuna caught in bait–boat fisheries before the spawning season (January, February and March), for each length class and year. In order to obtain a single fitness ratio (K–mean) per year we determined the average for all length classes. We also evaluated Le Cren’s condition index (K LC ). We observed significant positive correlations between the atmospheric oscillations and both physical condition indexes. In the case of K–mean, the AO explained 75% of the observed variability. Regarding K LC , the NAO explained approximately 73% of the observed variability, while the AO explained 70% of the observed variability. The increase in physical conditions of bluefin tuna in association with positive atmospheric oscillations could be mediated by the increase in the prevalence of strong trade winds. We concluded that the increase in the prevalence of strong westerly winds, mediated by a positive AO or NAO, favours the trip from the Atlantic to the Mediterranean by reducing energy costs due to migration and by increasing the supply of nutrients at the surface by the mixing of deep water and surface water in local areas such as the Strait of Gibraltar.

[Aim]: When faced with dichotomous events, such as the presence or absence of a species, discrimination capacity (the ability to separate the instances of presence from the instances of absence) is usually the only characteristic that is assessed in the evaluation of the performance of predictive models. Although neglected, calibration or reliability (how well the estimated probability of presence represents the observed proportion of presences) is another aspect of the performance of predictive models that provides important information. In this study, we explore how changes in the distribution of the probability of presence make discrimination capacity a context-dependent characteristic of models. For the first time, we explain the implications that ignoring the context dependence of discrimination can have in the interpretation of species distribution models. [Innovation]: In this paper we corroborate that, under a uniform distribution of the estimated probability of presence, a well-calibrated model will not attain high discrimination power and the value of the area under the curve will be 0.83. Under non-uniform distributions of the probability of presence, simulations show that a well-calibrated model can attain a broad range of discrimination values. These results illustrate that discrimination is a context-dependent property, i.e. it gives information about the performance of a certain algorithm in a certain data population. [Main conclusions]: In species distribution modelling, the discrimination capacity of a model is only meaningful for a certain species in a given geographic area and temporal snapshot. This is because the representativeness of the environmental domain changes with the geographical and temporal context, which unavoidably entails changes in the distribution of the probability of presence. Comparative studies that intend to generalize their results only based on the discrimination capacity of models may not be broadly extrapolated. Assessme

We explored the possible effects of the North Atlantic Oscillation (NAO) and Arctic Oscillation (AO) on interannual sea surface temperature (SST) variations in the Alborán Sea, both separately and combined. The probability of observing mean annual SST values higher than average was related to NAO and AO values of the previous year. The effect of NAO on SST was negative, while that of AO was positive. The pure effects of NAO and AO on SST are obscuring each other, due to the positive correlation between them. When decomposing SST, NAO and AO in seasonal values, we found that variation in mean annual SST and mean winter SST was significantly related to the mean autumn NAO of the previous year, while mean summer SST was related to mean autumn AO of the previous year. The one year delay in the effect of the NAO and AO on the SST could be partially related to the amount of accumulated snow, as we found a significant correlation between the total snow in the North Alborán watershed for a year with the annual average SST of the subsequent year. A positive AO implies a colder atmosphere in the Polar Regions, which could favour occasional cold waves over the Iberian Peninsula which, when coupled with precipitations favoured by a negative NAO, may result in snow precipitation. This snow may be accumulated in the high peaks and melt down in spring-summer of the following year, which consequently increases the runoff of freshwater to the sea, which in turn causes a diminution of sea surface salinity and density, and blocks the local upwelling of colder water, resulting in a higher SST.

The Alborán Sea hosts the largest population of common dolphin in the Mediterranean Sea. This species of cetacean has the highest number of recorded strandings on the Andalusian coast. We analyzed the spatial and temporal patterns of 633 short-beaked common dolphins stranded on this coast during the period 1996-2009. The spatial distribution of the strandings differed between the Atlantic and Mediterranean coasts of the Andalusian littoral. Mean body size was 163.3 ± 35.6 cm, although body size was not homogeneously distributed along the coast. These cetaceans tended to be larger on the Atlantic coast than on the rest of the Andalusian coast. Although others factors must be taken into account, the stranding patterns may be explained by the density of short-beaked common dolphins in inshore waters. The number of strandings suggests intense use by this species of the continental shelf along the Andalusian coast, with the possibility of conflict between dolphins and human activities in the Alborán Sea.

Fisheries by-catch is considered to be a major threat to loggerhead turtles in the Mediterranean Sea. Technical differences in both gear configurations (e.g. hook and bait type) and fisheries operations carried out by the Spanish Mediterranean surface longline fleet could have an effect on by-catch rates and size selectivity. The aim of the present study was to test the differences in by-catch per unit effort and body size of loggerhead sea turtles caught using different gear types in the Mediterranean surface longline fishery. Our results suggest that differences in the gear type used have an effect on catch rates and size selec- tivity. Thus, surface longliners targeting albacore (LLALB) using smaller hooks tend to capture smaller loggerheads but have the highest by-catch per unit of effort (BPUE), whereas other longlines, such as surface longliners targeting bluefin tuna (LLJAP) and traditional surface longliners targeting swordfish (LLHB), using larger hooks tend to select the larger animals; moreover, LLHB had the lowest BPUE. Disproportionate rates of fisheries-induced mortality on certain size/age- classes can differentially affect sea turtle populations, as each sea turtle age-class contributes differently to current and future reproduction. Thus, fisheries management should not only be focusing on preserving the large juvenile and mature turtles, but also on reducing the total by-catch. Thus, we recommend encouraging the use of LLHB versus other surface gears. We suggest that it is very important to take into account the gear type (and its particular catch rates) when making inferences about the impact of longline fisheries on sea turtle populations.

Hyperpredation can be described as a restrictive case of apparent competition where an increased number of primary prey species indirectly induces the decrease of the secondary prey species through numerical response of predators to the primary prey dynamics. It has been proposed that rabbit hemorrhagic disease (RHD), which decimated populations of European wild rabbit (Oryctolagus cuniculus) in Spain, led to prey switching by raptors towards red-legged partridges (Alectoris rufa) causing declines in their populations as a peculiar case of hyperpredation. We have reviewed field studies that disagree with estimates (based on bag records) of recent increases of rabbit and partridge numbers in Spain. Because of an increase in releases of farm-reared animals, there is doubt about the use of bag records to accurately estimate population trends in recent decades. We also provide new data and discuss some analytical considerations related to the temporal and spatial scales that might affect the interpretation of data. Finally, we discuss why studies associated with raptor food habits, predator population dynamics and predator distribution suggest that diet data are not sufficient to link patterns and processes. Although we agree that the RHD outbreak has markedly affected rabbit populations, which has indirectly affected many other species in the Iberian Peninsula, we consider that hyperpredation mediated by raptors has not been clearly demonstrated. In contrast, endorsing the hypothesis of raptor-mediated hyperpredation without sufficient proof may have conflictive consequences if we consider the increased persecution of raptors in recent decades in Spain.

Some species are very difficult to observe in the wild, and some of these present an apparently incongruent distribution, as is the case of the spur-thighed tortoise Testudo graeca in the southern Iberian Peninsula. This species has a discontinuous distribution with two main reproductive areas: one in the contiguous provinces of Almeria and Murcia, and the other in Huelva province. Both populations are thought to maintain reproductive isolation. However, we present new records obtained from two areas (the provinces of Malaga and Cadiz) which are outside their previously known range. Malaga province and Cadiz province are located between the two traditional reproductive areas. The new records were based on 16 interviews with shepherds as well as information provided by three naturalists. The aim of this work was to analyze the spatial distribution of areas favourable to the spur-thighed tortoise in the southern Iberian Peninsula, using different models with the same group of variables but with a different number of records: known records, new records and a combination of them. We obtained a distribution model for the species in Andalusia consistent with all observations, which was related to climatic stability, climatic disturbances, and spatial situation. This model presented three main favourable areas: two are coincident with the two known nuclei, and the other is situated in the southern part of the region, in the contiguous provinces of Cadiz and Malaga. We conclude that it is important to consider all the observations in the distribution models because records outside the traditional reproductive areas can include other environmental characteristics appropriate for the species.

The idea of analysing the general favourability for the occurrence of an event was presented in 2006 through a mathematical function. However, even when favourability has been used in species distribution modelling, the conceptual framework of this function is not yet well perceived among many researchers. The present paper is conceived for providing a wider and more in-depth presentation of the idea of favourability; concretely, we aimed to clarify both the concept and the main distinctive characteristics of the favourability function, especially in relation to probability and suitability, the most common outputs in species distribution modelling. As the capabilities of the favourability function go beyond species distribution modelling, we also illustrate its usefulness for different research disciplines for which this function remains unknown. In particular, we stressed that the favourability function has potential to be applied in all the cases where the probability of occurrence of an event is analysed, such as, for example, habitat selection or epidemiological studies.

[Aim]: The extent of the study area (geographical background, GB) can strongly affect the results of species distribution models (SDMs), but as yet we lack objective and practicable criteria for delimiting the appropriate GB. We propose an approach to this problem using trend surface analysis (TSA) and provide an assessment of the effects of varying GB extent on the performance of SDMs for four species. [Location]: Mainland Spain. [Methods]: Using data for four well known wild ungulate species and different GBs delimited with a TSA, we assessed the effects of GB extent on the predictive performance of SDMs: specifically on model calibration (Miller's statistic) and discrimination (area under the curve of the receiver operating characteristic plot, AUC; sensitivity and specificity), and on the tendency of the models to predict environmental potential when they are projected beyond their training area. [Results]: In the training area, discrimination significantly increased and calibration decreased as the GB was enlarged. In contrast, as GB was enlarged, both discriminatory power and calibration decreased when assessed in the core area of the species distributions. When models trained using small GBs were projected beyond their training area, they showed a tendency to predict higher environmental potential for the species than those models trained using large GBs. [Main conclusions]: By restricting GB extent using a geographical criterion, model performance in the core area of the species distribution can be significantly improved. Large GBs make models demonstrate high discriminatory power but are barely informative. By delimiting GB using a geographical criterion, the effect of historical events on model parameterization may be reduced. Thus purely environmental models are obtained that, when projected onto a new scenario, depict the potential distribution of the species. We therefore recommend the use of TSA in geographically delimiting the GB for use in SDMs.

The application of species distribution models (SDMs) in ecology and conservation biology is increasing and assuming an important role, mainly because they can be used to hindcast past and predict current and future species distributions. However, the accuracy of SDMs depends on the quality of the data and on appropriate theoretical frameworks. In this study, comprehensive data on the current distribution of the Iberian hare (Lepus granatensis) were used to i) determine the species' ecogeographical constraints, ii) hindcast a climatic model for the last glacial maximum (LGM), relating it to inferences derived from molecular studies, and iii) calibrate a model to assess the species future distribution trends (up to 2080). Our results showed that the climatic factor (in its pure effect and when it is combined with the land-cover factor) is the most important descriptor of the current distribution of the Iberian hare. In addition, the model's output was a reliable index of the local probability of species occurrence, which is a valuable tool to guide species management decisions and conservation planning. Climatic potential obtained for the LGM was combined with molecular data and the results suggest that several glacial refugia may have existed for the species within the major Iberian refugium. Finally, a high probability of occurrence of the Iberian hare in the current species range and a northward expansion were predicted for future. Given its current environmental envelope and evolutionary history, we discuss the macroecology of the Iberian hare and its sensitivity to climate change.

Parapatry is a biogeographical term used to refer to organisms whose ranges do not overlap, but are immediately adjacent to each other; they only co-occur - if at all - in a narrow contact zone. Often there are no environmental barriers in the contact zones, hence competitive interaction is usually advocated as the factor that modulates species distribution ranges. Even though the effects of climate change on species distribution have been widely studied, few studies have explored these effects on the biogeographical relationships between closely related, parapatric, species. We modelled environmental favourability for three parapatric hare species in Europe - Lepus granatensis, L. europaeus and L. timidus - using ecogeographical variables and projected the models into the future according to the IPCC A2 emissions scenario. Favourabilities for present and future scenarios were combined using fuzzy logic with the following aims: (i) to determine the biogeographical relationships between hare species in parapatry, that is L. granatensis/L. europaeus and L. europaeus/L. timidus and (ii) to assess the effects of climate change on each species as well as on their interspecific interactions. In their contact area L. granatensis achieved higher favourability values than L. europaeus, suggesting that if both species have a similar population status, the former species may have some advantages over the latter if competitive relationships are established. Climate change had the most striking effect on the distribution of L. timidus, especially when interspecific interactions with L. europaeus were taken into account, which may compromise the co-existence of L. timidus. The results of this study are relevant not only for understanding the distribution patterns of the hares studied and the effects of climate change on these patterns, but also for improving the general application of species distribution models to the prediction of the effects of climate change on biodiversity.

The aim of this study was to look into possible relationships between climate and the inter-annual variability of albacore (Thunnus alalunga) catch rates by age class observed during a recreational fishery tournament at the spawning grounds of S’Estanyol (Balearic Islands, Spain) in the years 2004–2009. The mean capture per unit effort (CPUE) was significantly higher when the mean of the North Atlantic Oscillation (NAO) experienced by the albacore in winter and spring of its life history (NAOlife) was negative than when the NAOlife was positive. A statistically significant negative relationship was obtained between NAOlife and the probability of a CPUE value for an age class and year being higher than the average CPUE for all the cohorts in that age class. The results suggest that local abundance of albacore in a spawning grounds could be related to environmental factors dependent on the NAO and that there may be a cohort-age effect. It is hypothesized that factors dependent on the NAO, such as the abundance variation of small pelagic fishes as a response to the NAO variability, could have a cumulative effect over the good biological condition (fitness) of a long-living fish predator such as the albacore.

In recent decades, Mediterranean landscapes have been experiencing more rapid changes in land use than usual, which have affected the ecology of the species inhabiting this biodiversity hotspot. Some studies have assessed the effect of such changes on biodiversity, but most of these were diachronic studies of population dynamics, or synchronic studies of species habitat selection, whereas few studies have simultaneously taken into account temporal changes in habitat composition and changes in species distribution. This study analysed the effects of land-use changes on the distribution of wild ungulates (Capreolus capreolus, Capra pyrenaica, Cervus elaphus and Sus scrofa). Using favourability function and Markov chain analysis combined with cellular automata, we addressed the following objectives: (i) to examine the environmental determinants of ungulate distribution in the past (1960s) and present (1990s), (ii) to model land use for 2040 to forecast future species distributions and (iii) to assess the biogeographical differences between the above-mentioned study periods (past-present and present-future). Species favourability was predicted to be more widely distributed in the present than in the past, but this increase varied across species. Areas predicted to be favourable in the present should remain stable in the future, but in addition there will be more new favourable areas not previously occupied by these species. The results are discussed from the perspective of the socio-economic relevance of wild ungulates in relation to some unfavourable areas of Mediterranean regions.

The Iberian wild goat (Capra pyrenaica), an endemic species to the Iberian Peninsula, was represented in the past by four subspecies. Currently, the conservation status of the recognized subspecies - C. p. hispanica and C. p. victoriae - is quite different, being the former broadly distributed while the latter inhabits fewer and smaller areas. In this global context, our specific aims were to assess the biogeographical relationships, similarities and differences between the Iberian wild goat subspecies, and to evaluate their conservation status from a biogeographical perspective. We modelled the ecogeographical favourability for each subspecies, and also for the whole species, and we comparatively analyzed the spatial relationships among models in order to detect differential biogeographical patterns. Our results showed a differential pattern for each Iberian wild goat subspecies, and thus each one should be independently considered when designing management strategies. The distribution of C. p. victoriae was closely related to climatic conditions, thus it is highly sensitive to variations in climatic characteristics. Finally, from the perspective of metapopulation theory, and according to the geographical structure of their favourable areas, C. p. victoriae is at higher risk than C. p. hispanica. We discuss the implications of our results for species/subspecies conservation, and highlight the importance of conservation biogeography.

[EN]: Species distribution models (SDM) are widely used in ecology, biogeography and conservation. Here, we modelled the distribution of roe deer (Capreolus capreolus) in mainland Spain in order to i) determine its macro-ecological requirements, ii) assess the favourability for this species and iii) explore the model usefulness as an index of the species relative abundance. Our results showed that roe deer distribution can be explained by predictors related with topography, climate, lithology, geography and human activity. Climate was the more relevant factor, followed by human activity, topography, spatial location and lithology. The model accurately predicted the species probability of occurrence and also, but weakly, the species' relative abundance., [ES]: Los modelos de distribución de especies (SDM) están siendo cada vez más usados para abordar cuestiones relacionadas con la ecología, biogeografía y conservación de las especies. En este estudio nos proponemos realizar un modelo de distribución para el corzo (Capreolus capreolus) en la España peninsular para estudiar los determinantes macroambientales de su rango de distribución, evaluar la favorabilidad para la especie, y la utilidad del modelo como indicador de su abundancia relativa. El modelo indica que su distribución se puede explicar en términos topográficos, climáticos, litológicos, geográficos y de presión humana. El clima fue el factor que en su efecto puro explicó un mayor porcentaje de variación, y le siguen la presión humana, la topografía, la localización espacial y la litología. El modelo obtenido predijo con elevada precisión la probabilidad de presencia de la especie y con cierto detalle su abundancia relativa.

The effectiveness of selecting umbrella species or groups of species to protect other groups is a key and unresolved issue in conservation planning. We detected areas important to the four groups of terrestrial vertebrates inhabiting Andalusia (southern Spain) according to four conservation-value criteria, i.e., richness, rarity, vulnerability, and endemicity. We calculated coincidences between criteria and taxa by the degree of correlation and fuzzy overlap between the different criteria for the same group (intra-group coincidence) and between the different groups of species for the same criteria (inter-group coincidence). For the groups to be appropriate umbrella species, inter-group coincidence should be high. The results showed that intra-group coincidence was high, but inter-group coincidence was low. Thus, zones of importance to each group of species tended to be located in different places compared to the other groups, and therefore none of them should be used as an indicator or umbrella group to protect the others. This result has implications for conservation policy, as the Andalusian authorities should not assume that protecting a site important to one group of species will also be relevant to conserve the other groups. Nevertheless, we identified the areas of relatively high conjoint importance for all the groups, and the best umbrella group in this region, which proved to be reptiles.

[EN]: Iberian wild goat subsp. Capra pyrenaica victoriae inhabits fewer and smaller areas than subs. C. p. hispanica reason why the former is considered as Vulnerable by IUCN. Therefore studies aimed to assess the status of C. p. victoriae are very valuables. We studied the habitat use, parasite excretion rates and diet quality of the Montes de Toledo's C. p. victoriae population. The red deer is a potential competitor of the Iberian wild goat and subsequently was included in this study. Our results showed that both species had a good population status (good corporal condition, high quality diet and suitable population density). According to the indicators considered in this study we do not expect that red deer suppose a relevant risk for the viability of the Iberian wild goat population. The implications of the results to Iberian wild goat management are deeper discussed., [ES]: La Capra pyrenaica victoriae presenta pocas poblaciones y éstas ocupan áreas reducidas, siendo considerada por ello por la IUCN como vulnerable. Son necesarios, por tanto, estudios locales encaminados a evaluar el estado de dichas poblaciones. En este trabajo estudiamos la población presente en los Montes de Toledo a través del análisis del uso que hace del hábitat, del nivel de parasitación y de la calidad de su dieta. El ciervo fue también incluido en este esquema de monitorización por ser un potencial competidor para la cabra montés. Los resultados indican que ambas especies presentan un adecuado estado poblacional (buena condición corporal, dieta de elevada calidad y valores de densidad razonables). Según los indicadores considerados no sería esperable que el ciervo supusiera un riesgo relevante para la viabilidad de la población de cabra montés. Se discuten las implicaciones de los resultados para la gestión cinegética de la cabra montés.

We tested two approaches to forecast species distributions while balancing the impact of climate change against the inertia promoted by other influential factors that have been forecast as not changing. Given that mountain species are presumed to be more at risk due to climate warming, we selected an amphibian, a reptile, a bird, and a mammal species present in the Spanish mountains, to model their distributional response to climate change during this century. The climatic forecasts were made according to the general circulation models CGCM2 and ECHAM4 and to the A2 and B2 emission scenarios. We modelled the response of the species to spatial, topographic, human, and climatic variables separately. In our first approach, we compared each of these single-factor models using the Akaike Information Criterion, and produced a combined model weighting each factor (spatial, topographic, human, and climatic) according to Akaike weights. This procedure overestimated the best model, and the other factors were neglected in the combined model output. In our second approach, we produced a combined model using stepwise selection of the variables previously selected within each factor. In this way every factor was effectively represented in the combined explanatory model of the distributional response of the species to environmental conditions. This enabled the construction of models that combined climate with the other explanatory factors, to be later extrapolated to the future by replacing current climatic and human values with those expected from each emission and socio-economic scenario, while preserving spatial and topographic variables in the model.

We compared the effect of general circulation models and greenhouse gas emission scenarios on the uncertainty associated with models predicting changes in areas favourable to animal species. Given that mountain species are particularly at risk due to climate warming, we selected one amphibian (Baetic midwife toad), one reptile (Lataste's viper), one bird (Bonelli's eagle), and one mammal (Iberian wild goat) present in Spanish mountains to model their distributional response to climate change during this century. Climate forecasts for the whole century were provided by the Agencia Estatal de Meteorologiá (AEMET; National Meteorological Agency) of Spain, which adapted the general circulation models CGCM2 and ECHAM4 and produced expected temperature and precipitation values for Spain according to the A2 and B2 emission scenarios. We constructed separate models of the species response to spatial, topographic, human, and climate variables using current values of the corresponding variables. We predicted future areas favourable to the species by replacing the current climate values with those expected according to each climate change scenario, while keeping spatial, topographic and human variables constant. Fuzzy logic was used to compute the coincidence between predictions for different emission scenarios in the same global circulation model, and the consistency between predictions for the same emission scenario applying different general circulation models. In general, coincidences were higher than consistencies and, thus, discrepancies between predictions were more attributable to uncertainty in global circulation models, i.e. our insufficient knowledge concerning the effect of the oceans and atmosphere on climate, than to the putative effect of different emission scenarios on future climates. Our conclusion is that species distribution models in climate warming scenarios are still not useful for informing emission policy planning, although they have great potential as

[EN]: Seabird by-catch caused by longline fisheries is the most critical global threat to seabirds, mainly tubenose petrels. The Western Mediterranean is an important fishing area where the Spanish drifting longline operates. By-catch of these fisheries includes several resident and non-resident seabird species of different conservation concern. One of the main goals of seabird conservation is to disentangle the factors determining by-catch and to identify which management and conservation actions are necessary to mitigate this problem. In this paper, we modeled the effects of surface longline and its interaction with others fisheries on seabird by-catch. We used data recorded by onboard observers of the Spanish Institute of Oceanography (IEO) within the monitoring program for commercial longline fisheries from 2000 to 2009. We estimated a favourability function from logistic regression where the dependent variable was the presence or absence of seabird by-catch per set and the independent variables were those related to technical characteristics of the fishery, interactions with other fisheries, geographical location, and month. The interaction with other fisheries was estimated as the number of working and non-working days (weekend and official holidays), because the Spanish fishing legislation only allows longliners to operate in non-working days. We obtained a statistically significant favourability model with the following variables: traditional longline targeting swordfish, longline targeting albacore, number of hooks, latitude where the setting started, fisheries over continental shelf, October, and non-working days. The difference of the favourability function between working and non-working days provided a measure of the effect of non-working days on seabird by-catch. We concluded that the effects of the interaction with others fisheries on seabird by-catch are important, making non working days 48% more favourable than working days for increase seabird by, [ES]: La captura accesoria de aves en palangre es una amenaza crítica para las aves marinas, fundamentalmente para los procelariformes. El Mediterráneo occidental es una zona de pesca importante en la que opera la pesquería de palangre española a la deriva. Las capturas accesorias de estas pesquerías incluyen varias especies de aves marinas tanto residentes como no residentes y de diferente preocupación de conservación. La comprensión de los factores que determinan las capturas accesorias y cómo mitigarlos es una meta importante en la biología de la conservación de las aves marinas. En este trabajo se ha modelado el efecto que el palangre y su interacción con otras artes de pesca producen sobre las capturas accesorias de aves marinas. Se utilizaron los datos registrados por un programa de observadores a bordo, de seguimiento de la pesca comercial con palangre, del Instituto Español de Oceanografía desde el año 2000 hasta el 2009. Se aplicó una función de favorabilidad donde la variable dependiente era la captura accesoria de un ave marina y las variables independientes estaban relacionadas con las características técnicas de la pesquería, la interacción con otras pesquerías, las condiciones geográficas y la estacionalidad. Las interacciones con otras pesquerías se calcularon como el número de días no laborables en los que se pescó, porque según la normativa española la única pesquería que puede operar en días no laborables es el palangre. Se obtuvo un modelo de favorabilidad con un buen ajuste, estadísticamente significativo, con las variables: palangre tradicional dirigido al pez espada, palangre dirigido al atún blanco, número de anzuelos, la latitud al inicio de la calada, pesca sobre la plataforma continental, octubre y días no laborables. La diferencia de la función de favorabilidad entre días laborales y no laborales da una medida del efecto de los días no laborables en las capturas accesorias de aves marinas. Se concluye que los efectos de la interacción con