We aimed to identify the existence of age-classes groups that shared similar seasonal patterns in... more We aimed to identify the existence of age-classes groups that shared similar seasonal patterns in migration movements for the lesser black-backed gull Larus fuscus. The gull age-classes groups were defined as sets of age-classes that were present in the harbour of Malaga (South of Spain) simultaneously during the wintering season. We distinguished ten groups of age-classes, which can be subsequently lumped into four big age-class groups: (i) immature stage-class, (ii) young breeders, (iii) age-classes from 6 to 11 years old, and (iv) age-classes older than 11 years old. Our present results supported the 'dominance and arrival time model'. RESUMEN.-Se pretendía identificar la existencia de grupos de clases de edad con un patrón estacional similar en la gaviota sombría Larus fuscus. Los grupos se definieron como conjuntos de clases de edad que estuvieron presentes de forma simultánea siguiendo un mismo patrón temporal en el puerto de Málaga durante la temporada de invernada. Se distinguieron diez grupos de clases de edad, los cuales a su vez pueden agruparse en cuatro grandes grupos: (i) inmaduros, (ii) jóvenes reproductores, (iii) clases de edad de 6 a 11 años y (iv) clases de aves mayores de 11 años. Nuestros resultados apoyan la teoría de la 'posición dominante y el modelo de la hora de llegada'.
Utilidad de los espacios naturales protegidos de Andalucía para preservar la riqueza de especies de anfibios
Munibe. Suplemento, 2007
Información del artículo Utilidad de los espacios naturales protegidos de Andalucía para preserva... more Información del artículo Utilidad de los espacios naturales protegidos de Andalucía para preservar la riqueza de especies de anfibios.
In Europe, hunting and game management are centuries-old activities that have had profound effect... more In Europe, hunting and game management are centuries-old activities that have had profound effects on the landscapes and the biodiversity they support. Game management is a potentially important tool to enhance game populations, and may also affect other wildlife. We investigated the relationship between red-legged partridge (Alectoris rufa) game management and steppe-bird abundance in central Spain. We surveyed 54 red-legged partridge hunting estates with varying game-management intensity in spring and/or summer in 2006 and 2008-2010. Information about game management was gathered through questionnaires to game managers. Birds were counted from fixed points and the amount of different land uses in each point was visually estimated. Our results show that the abundance of granivorous species (sandgrouse) increased significantly with the density of feeders, whereas nongranivorous species were more abundant in estates with more intensive fox control, although the latter relationship was weaker. Land-use variables, specifically agricultural lands, appeared in the models of all the groups considered. Therefore, there is an option for designing optimal management for red-legged partridge estates that potentially benefits non-target species: an effective combination of habitat management, adequate use of supplementary food and water, and possibly selective legal predator control when necessary and effective for the target game species, although the latter needs further investigation.
Differential age-related phenology in lesser black-backed gull "Larus fuscus" wintering in the Malaga area = Fenología diferencial relacionada con la edad en la gaviota sombría "larus fuscus" desde el área de invernada de Málaga
Ardeola, 2010
Informaci??n del art??culo Differential age-related phenology in lesser black-backed gull "L... more Informaci??n del art??culo Differential age-related phenology in lesser black-backed gull "Larus fuscus" wintering in the Malaga area = Fenolog??a diferencial relacionada con la edad en la gaviota sombr??a "larus fuscus" desde el ??rea de invernada de M??laga.
Entropy is intrinsic to the geographical distribution of a biological species. A species distribu... more Entropy is intrinsic to the geographical distribution of a biological species. A species distribution with higher entropy involves more uncertainty, i.e., is more gradually constrained by the environment. Species distribution modelling tries to yield models with low uncertainty but normally has to reduce uncertainty by increasing their complexity, which is detrimental for another desirable property of the models, parsimony. By modelling the distribution of 18 vertebrate species in mainland Spain, we show that entropy may be computed along the forward-backwards stepwise selection of variables in Logistic Regression Models to check whether uncertainty is reduced at each step. In general, a reduction of entropy was produced asymptotically at each step of the model. This asymptote could be used to distinguish the entropy attributable to the species distribution from that attributable to model misspecification. We discussed the use of fuzzy entropy for this end because it produces results that are commensurable between species and study areas. Using a stepwise approach and fuzzy entropy may be helpful to counterbalance the uncertainty and the complexity of the models. The model yielded at the step with the lowest fuzzy entropy combines the reduction of uncertainty with parsimony, which results in high efficiency.
The risk climate change poses to biodiversity is often estimated by forecasting the areas that wi... more The risk climate change poses to biodiversity is often estimated by forecasting the areas that will be climatically suitable for species in the future and measuring the distance of the "range shifts" species would have to make to reach these areas. Species' traits could indicate their capacity to undergo range shifts. However, it is not clear how range-shift capacity influences risk. We used traits from a recent evidence review to measure the relative potential of species to track changing climatic conditions. Location: Europe.
Proceedings of The Royal Society B: Biological Sciences, Jun 14, 2017
Understanding and forecasting the effects of environmental change on wild populations requires kn... more Understanding and forecasting the effects of environmental change on wild populations requires knowledge on a critical question: do populations have the ability to evolve in response to that change? However, our knowledge on how evolution works in wild conditions under different environmental circumstances is extremely limited. We investigated how environmental variation influences the evolutionary potential of phenotypic traits. We used published data to collect or calculate 135 estimates of evolvability of morphological traits of European wild bird populations. We characterized the environmental favourability of each population throughout the species' breeding distribution. Our results suggest that the evolutionary potential of morphological traits decreases as environmental favourability becomes high or low. Strong environmental selection pressures and high intra-specific competition may reduce species' evolutionary potential in low-and highfavourability areas, respectively. This suggests that species may be least able to adapt to new climate conditions at their range margins and at the centre. Our results underscore the need to consider the evolutionary potential of populations when studying the drivers of species distributions, particularly when predicting the effects of environmental change. We discuss the utility of integrating evolutionary dynamics into a biogeographical perspective to understand how environmental variation shapes evolutionary patterns. This approach would also produce more reliable predictions about the effect of environmental change on population persistence and therefore on biodiversity.
Predicting distribution has become a fundamental component in conservation or wildlife management... more Predicting distribution has become a fundamental component in conservation or wildlife management. Modelling is increasingly used to identify important areas (e.g. those areas more suitable for a species or more likely to hold high densities). Models often use presence/absence rather than abundance data, partly because measuring abundance is more difficult than measuring presence. We aimed to test if the relationship between occurrence models and predicted abundance varied for two sibling species that differ in the level of nest aggregation: the Montagu's harrier (a semi-colonial raptor species) and the hen harrier (more territorial). We modelled presence/absence distribution and the number of pairs of each species with GLM and large-scale environmental variables, and compared predicted results of both sets of models. In the case of the hen harrier, predictions of the presence/absence model reliably identified areas with highest densities for the species. In contrast, in the Montagu´s harrier, there were large apparently favourable areas where predicted breeding density was low. Our results indicate that breeding system is likely to shape the relationship between presence/absence vs density models. In species that are randomly or evenly spaced, even if spatial variations in density occur, using results of presence/absence models is likely to be adequate for population monitoring. In contrast, in the case of semi-colonial species, it is necessary to take into account both occurrence and abundance models to identify areas of conservation importance or concern. There are a considerable number of birds which are semi-colonial or aggregated species, thus these results have general implications.
Aim: To describe the population trend for European turtle doves in Spain. To identify favourable ... more Aim: To describe the population trend for European turtle doves in Spain. To identify favourable and unfavourable areas for the species and to test whether favourability or land use explain spatial variation in abundance change. Location: Mainland Spain. We used generalized linear models with extensive abundance data to describe population change for the European turtle dove across Spain. We used breeding distribution (presence/absence) data at 100 km 2 resolution to model environmental favourability in relation to topo-climatic and land use variables. Finally, we tested whether land use and favourability explained spatial variation in abundance trends. The large Spanish turtle dove population declined by 37% between 1996 and 2018. Favourability was highest in the south, east and north-west of Spain and lowest in the north and at higher altitudes. Abundance trends were more negative in areas of lower environmental favourability and in localities dominated by arboreal habitats such as forests, "dehesas" (open agro-forestry landscapes with scattered Quercus trees), transitional woodland shrubs or sclerophyllous vegetation (a mixture of sclerophyllous shrubs with some scattered trees). Trends were more positive in localities dominated by complex cultivation (small parcels of mixed crop types, including woody permanent crops like olive, or almond trees or vineyards). Our study highlights a substantial recent decline in the numerically important turtle dove breeding population in Spain. Declines in abundance were more strongly associated with arboreal (forest and shrub areas) rather than agricultural habitats, highlighting an urgent need for further research into the ecology of this important quarry species in arboreal breeding habitats in southern Europe.
Information on species' ecological traits might improve predictions of climate-driven range shift... more Information on species' ecological traits might improve predictions of climate-driven range shifts. However, the usefulness of traits is usually assumed rather than quantified. We present a framework to identify the most informative traits, based on four key range-shift processes: (i) emigration of individuals or propagules away from the natal location, (ii) the distance a species can move, (iii) establishment of self-sustaining populations, and (iv) proliferation following establishment. We propose a framework that categorises traits according to their contribution to range-shift processes. We demonstrate how the framework enables the predictive value of traits to be evaluated empirically, how this categorisation can be used to better understand range shift processes, and illustrate how range shift estimates can be improved. Mitigating the threat from climate change to biodiversity and ecosystems requires a robust understanding of how species will respond to new climatic conditions. The most common method for estimating a species' exposure to climate change is to compare future climatic conditions against the conditions in which a species currently lives . While there is disagreement about the accuracy of these techniques, they are well explored, and there is literature on best practice . Species vulnerability to exposure is less well understood. A major uncertainty is whether species are able to colonise newly climatically suitable areas once current geographic ranges become unsuitable. Such "range shifts" (see Glossary) could mitigate threats from climate change.
Dado que la función de favorabilidad se puede considerar como análoga a la función de onda, utili... more Dado que la función de favorabilidad se puede considerar como análoga a la función de onda, utilizada en física cuántica como verdadera distribución de las partículas físicas, la verdadera distribución de las especies de mamíferos en España vendría dada por sus respectivas funciones de favorabilidad, y los cambios experimentados en esas distribuciones estarían representados por los cambios en sus funciones de favorabilidad a lo largo del tiempo. Esta función permite medir la diversidad oscura de una zona, que ha sido definida recientemente como el conjunto de especies que podrían habitar en ella, dadas sus condiciones ambientales, pero que no han sido detectadas allí. Se han publicado novedosas medidas de la biodiversidad derivadas de estos conceptos, como son la biodiversidad potencial (suma de favorabilidades), la media geométrica de favorabilidades, y la biodiversidad oscura (suma de favorabilidades para las especies ausentes de un territorio). Estas medidas fueron aplicadas para los mamíferos en los Parques Nacionales de España peninsular en dos periodos de tiempo (2002 y 2015). La diversidad potencial de mamíferos fue mayor en la red de Parques Nacionales que fuera de la red, y los Parques con mayor diversidad fueron Parques montañosos ubicados en el norte de España. Sin embargo, estos parques de alta diversidad potencial tuvieron áreas algo menos favorables para los mamíferos en 2015 en comparación con 2002. La diversidad de mamíferos en los Parques Nacionales Españoles debería ser evaluada nuevamente a medio plazo cuando se disponga de datos de distribución actualizados, para evaluar si la tendencia de estos Parques a contener áreas menos favorables se mantiene o no. Esto tendrá importantes implicaciones para la conservación en los parques montañosos, para mantener altos niveles de diversidad de mamíferos. Se presentan ejemplos de especies que están ausentes de determinados parques pero tienen potencial para estar presentes dada la favorabilidad local, es decir, forman parte de la biodiversidad oscura del parque. Parte de esta biodiversidad que era oscura en 2002 pasó a ser biodiversidad clara en 2015.
La deinición de patrones de distribución característicos (corotipos) tiene aplicaciones important... more La deinición de patrones de distribución característicos (corotipos) tiene aplicaciones importantes en biogeografía y conservación. Se basa en la comparación de presencias y ausencias de especies en distintas localidades o en una malla de unidades geográicas operativas (OGUs) como, por ejemplo, cuadrículas. El tipo y tamaño de las OGUs afecta a los corotipos resultantes, y cualquier parcelación del territorio implica una distorsión de la información. Por ejemplo, dos especies pueden quedar solapadas si ambas intersectan una misma cuadrícula, aunque estén separadas por una barrera geográica que atraviesa esa cuadrícula. Aquí se presenta una adaptación de los índices de similitud comúnmente utilizados para comparar patrones de distribución (ej. Jaccard; Baroni-Urbani y Buser), basada en el tamaño de las intersecciones y uniones de las áreas de distribución. Esto permite comparar distribuciones sin dividirlas en OGUs, eliminando los consiguientes artefactos. El método se implementa en un paquete informático libre que incluye un tutorial. Palabras clave: artefactos, corología, metodología, parcelación territorial, patrones de distribución.
This is a PDF file of an article that has undergone enhancements after acceptance, such as the ad... more This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
The evaluation of protected area networks on their capacity to preserve species distributions is ... more The evaluation of protected area networks on their capacity to preserve species distributions is a key topic in conservation biology. There are different types of protected areas, with National Parks those with highest level of protection. National Parks can be declared attending to many ecological features that include the presence of certain animal species. Here, we selected 37 vertebrate species that were highlighted as having relevant natural value for at least one of the 10 National Parks of mainland Spain. We modelled species distributions with the favourability function, and applied the Insecurity Index to detect the degree of protection of favourable areas for each species. Two metrics of Insecurity Index were defined for each species: the Insecurity Index in each of the cells, and the Overall Insecurity Index of a species. The former allows the identification of insecure areas for each species that can be used to establish spatial conservation priorities. The latter gives a value of Insecurity for each species, which we used to calculate the Representativeness of favourable areas for the species in the network. As expected, due to the limited extension of the National Park network, all species have high values of Insecurity; i.e., just a narrow proportion of their favourable areas are covered by a National Park. However, the majority of species favourable areas are well represented in the network, i.e., the percentage of favourable areas covered by the National Park network is higher than the percentage of mainland Spain covered by the network (result also supported by a randomization approach). Even if a reserve network only covers a low percentage of a country, the Overall Insecurity Index allows an objective assessment of its capacity to represent species. Beyond the results presented here, the Insecurity Index has the potential to be extrapolated to other areas and to cover a wide range of species.
AimClimate change impacts forest functioning and services through two inter‐related effects. Firs... more AimClimate change impacts forest functioning and services through two inter‐related effects. First, it impacts tree growth, with effects, for example, on biomass production. Second, climate change also reshuffles community composition, with further effects on forest functioning. However, the relative importance of these two effects has rarely been studied. Here, we developed a new modelling approach to investigate these relative importances for forest productivity.LocationEleven forest sites in central Europe.Time periodHistorical (1990) and end‐of‐21st‐century climate‐like conditions. We simulated 2,000 years of forest dynamics for each set of conditions.Major taxa studiedTwenty‐five common tree species in European temperate forests.MethodsWe coupled species distribution models and a forest succession model, working at complementary spatial and temporal scales, to simulate the climatic filtering that shapes potential tree species pools, the biotic filtering that shapes realized com...
AimTo describe the population trend for European turtle doves in Spain. To identify favourable an... more AimTo describe the population trend for European turtle doves in Spain. To identify favourable and unfavourable areas for the species and to test whether favourability or land use explain spatial variation in abundance change.LocationMainland Spain.MethodsWe used generalized linear models with extensive abundance data to describe population change for the European turtle dove across Spain. We used breeding distribution (presence/absence) data at 100 km2 resolution to model environmental favourability in relation to topo‐climatic and land use variables. Finally, we tested whether land use and favourability explained spatial variation in abundance trends.ResultsThe large Spanish turtle dove population declined by 37% between 1996 and 2018. Favourability was highest in the south, east and north–west of Spain and lowest in the north and at higher altitudes. Abundance trends were more negative in areas of lower environmental favourability and in localities dominated by arboreal habitats ...
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