La mirada de Gerda Taro y Robert Capa en Valencia durante el Segundo Congreso Internacional de escritores para la defensa de la cultura

El Segundo Congreso Internacional de Escritores para la Defensa de la Cultura celebrado en Valencia durante la Guerra Civil Española desvió la mirada mundial hacia la ciudad. El acontecimiento atrajo a un gran número de intelectuales y corresponsales extranjeros, entre ellos los fotoperiodistas Gerda Taro y Robert Capa, que documentaron juntos el acto de inauguración el día 4 de julio de 1937. A través del análisis pormenorizado de una fotografía realizada por Gerda Taro a la escritora Anna Seghers, este artículo realiza una lectura del contexto los días en los que Valencia se convirtió en el centro mundial de la intelectualidad antifascista

Occurrence vs abundance models: Differences between species with varying aggregation patterns

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 could have general implications.A. Estrada had a postdoctoral contract jointly financed by the European Social Fund and by the Junta de Comunidades de Castilla-La Mancha (Spain), in the framework of the Operational Programme FSE 2007-2013.Peer Reviewe

Appropriateness of Special Protection Areas for wide-ranging species: the importance of scale and protecting foraging, not just nesting habitats

Effective conservation plans and design of Special Protection Areas (SPAs) for protected species should take into account ranging behaviour and foraging habitats, and this is particularly important for wide-ranging species. Montagu's harriers Circus pygargus are ground-nesting semi-colonial raptors typical of agricultural habitats. We studied the foraging behaviour of 14 radio-tracked male Montagu's harriers, in order to investigate the distance from nests of foraging birds, the extent to which foraging range overlapped with SPAs designated for this species, and foraging habitat selection within foraging ranges. Average foraging range size, estimated from either minimum convex polygon or kernel 90%, was larger than 100km2. Only 19 ± 11% of the foraging ranges were within SPA limits. Cereal (the main habitat used for nesting) was slightly counterselected for foraging, and most prey (64%, n=117) captured in that habitat were insects. Hunting attempts occurred significantly more frequently than expected in alfalfa, where most prey captured were small mammals (70%, n=102). Use of this habitat for foraging increased throughout the season. Most prey captured in other habitats (mainly tree crops, shrubs or uncultivated land) were birds (83%, n=43). SPAs included a higher proportion of cereal, but a lower proportion of alfalfa than areas outside SPAs. Overall, our results show that breeding Montagu's harriers use an area for foraging much larger than current sizes of most SPAs for the species, that habitats selected for foraging differ from those used for nesting and that preferred foraging habitats were less common inside SPAs than outside. Conservation management for this species should aim to protect foraging habitats within a large radius of the colonies, probably requiring measures to be applied outside protected areas. More generally, SPAs designed without including information of ranging behaviour and foraging habitats may be ineffective.We thank to the Department de Medi Ambient i Habitatge, Regsega and the Centre Tecnològic Forestal de Catalunya for financial and logistic support for the programme.Peer Reviewe

Standing out from the crowd: are patagial wing tags a potential predator attraction for harriers (Circus spp.)?

et al.Wing tags have been used on many bird species to facilitate individual recognition, although tags are not only conspicuous for humans but may also attract the attention of potential predators. During a Peregrine Falcon Falco peregrinus monitoring program (1997-2011) we collected prey remains from the nests of 37 Peregrine territories in the Basque Country, Northern Spain. We identified 3,127 prey items representing 132 bird species. In the 2009 breeding season, we found, for the first time, four Hen Harrier Circus cyaneus remains and the two wings with orange wing tags of a Montagu's Harrier Circus pygargus in one nest, 1 year later we found in the same nest eight Montagu's Harrier remains, one of them with wing tags, and in 2011 we found eight more Montagu's Harriers, one of them marked. Simultaneously, in the breeding season of 2010, the remains of another Montagu's Harrier were found in other Peregrine nest and two wings with orange and blue wing tags in the perch of a third pair. Our data thus shows an increase of predation rate of harriers by Peregrines; we discuss whether this could be related to the increasing use of wing tags in this species, and thus whether wing tags may have potential negative effects on the birds. We argue that further studies about the impact of identification techniques, and wing-tags in particular, on the survival of target species should be carried out.Peer Reviewe

Hunting for sustainability: a summary of research findings from Spain

The HUNTing for Sustainability multi-discplinary research project has been funded by the European Union’s 7th Framework Research Programme. The project involved cooperation with a range of institutions and included case studies from Norway, Sweden, Scotland, Spain, Slovenia, Croatia, Ethiopia and Tanzania. The primary research activity in Spain has been related to assessing costs and benefits of different management styles for red-legged partridge hunting.N

L’adéquation fonctionnelle de l’habitat et l’empiètement urbain expliquent les variations temporelles et spatiales de l’abondance d’un oiseau champêtre en déclin, l’Outarde canepetière, Tetrax tetrax

Species response to land use can be examined under a functional perspective, where habitats are described according to species´ resource dependencies. Distribution or abundance models based on resource availability rather than land use types can be more informative about the ultimate processes behind observed population or distribution trends. Habitat use may depend on resources available, as well as disturbances that affect accessibility to such resources. Increasing human presence and urban encroachment may thus alter the relationships between habitat suitability and species abundance. Using 10 years of field data, we investigated whether variability in Little Bustard (Tetrax tetrax) abundance was explained by functional habitat suitability (assessed through resource-based models) and urban encroachment. We found that spatial and temporal variations in Little Bustard abundance were explained by functional habitat suitability and avoidance of urban areas, but that the significance of each variable varied with spatial scale. Little Bustard abundance at each observation point significantly increased with local nesting but not foraging habitat suitability, and decreased with increasing proportion of urban areas. At larger spatial scales, temporal changes in Little Bustard abundance were highly significantly related to changes in foraging habitat suitability. Moreover, the positive relationship between foraging habitat suitability and Little Bustard abundance weakened as the proportion of urban areas increased, and almost disappeared when the proportion of urban areas was more than 5%. Our results underline the benefits of using resource-based models to better understand processes that relate animal abundance and habitat suitability, while simultaneously considering avoided elements of the landscape.Le comportement des espèces en fonction de l’affectation des terres peut être examiné dans une perspective fonctionnelle, selon laquelle les habitats sont décrits suivant la dépendance des espèces envers les ressources. Les modèles de répartition ou d’abondance fondés sur la disponibilité des ressources, plutôt que sur le type d’affectation des sols, peuvent être plus informatifs sur les processus ultimes qui sous-tendent les tendances observées en matière de population ou de répartition. L’utilisation de l’habitat peut dépendre des ressources disponibles et des perturbations qui affectent l’accessibilité à ces ressources. La présence humaine croissante et l’empiètement urbain accru peuvent donc modifier les relations entre l’adéquation de l’habitat et l’abondance des espèces. En utilisant 10 ans de données prises sur le terrain, nous avons cherché à savoir si la variabilité de l’abondance de l’Outarde canepetière (Tetrax tetrax) s’expliquait par l’adéquation fonctionnelle de l’habitat (évaluée par des modèles basés sur les ressources) et l’empiètement urbain. Nous avons constaté que les variations spatiales et temporelles de l’abondance de l’Outarde canepetière s’expliquaient par l’adéquation fonctionnelle de l’habitat et l’évitement des zones urbaines, mais que l’importance de chaque variable variait selon l’échelle spatiale. L’abondance de l’outarde à chaque point d’observation a augmenté significativement avec l’adéquation de l’habitat local pour la nidification mais pas pour l’alimentation, et a diminué avec la proportion croissante de zones urbaines. À des échelles spatiales plus grandes, les changements temporels de l’abondance de l’outarde étaient fortement liés aux changements de l’adéquation de l’habitat pour l’alimentation. De plus, la relation positive entre l’adéquation de l’habitat pour l’alimentation et l’abondance de l’outarde a diminué à mesure que la proportion de zones urbaines augmentait, et l’espèce était presque totalement absente lorsque la proportion de zones urbaines était supérieure à 5 %. Les présents résultats soulignent les avantages de l’utilisation de modèles fondés sur les ressources pour qu’on comprenne mieux les processus qui relient l’abondance des animaux et l’adéquation de l’habitat, tout en considérant simultanément les éléments du paysage qui sont évités.CSICBanco Santander FGCSIC MCYT-REN2003-07851/GLO CGL2004-02568/BOS CGL2007-66322/BOS CGL2008-04282/BO

Diet composition and foraging success in generalist predators: Are specialist individuals better foragers?

[EN]: Factors affecting individual diet specialization in generalist populations and the relationship between diet and foraging success remain poorly studied, particularly in terrestrial wide-ranging predators. We studied whether individual variations in diet in Montagu's harrier males (determined through a combination of direct foraging observations and pellet analysis) were associated with patterns of foraging habitat selection and foraging success of 12 radiotracked males during the breeding period. We found important differences in diet composition and breadth between individuals. Diet diversity was negatively related to hunting success: the most efficient individuals in terms of hunting success had the most specialized diet. This study also suggests an important role of individual foraging habitat selection in explaining individual diet, as the proportion of different prey types in the diet was associated with habitat composition within the home range, with higher proportion of those habitats that held higher abundances of their more frequent prey. This study thus provides evidence of individual diet specialization having a knock-on effect on foraging efficiency in a wide-ranging raptor and highlights the role of individual behaviour as a driving force of intra-population niche variation.The authors would like to thank the Centre Tecnològic Forestal de Catalunya for financial and logistic support. BA was supported by a Mobility Grant funded by the Spanish Ministry of Education and Culture (Salvador de Madariaga call, grant number PRX12/00181) while working on this paper in CEBC.Peer Reviewe

Influence of game crops on the distribution and productivity of red-legged partridges Alectoris rufa in Mediterranean woodlands

Red-legged partridges Alectoris rufa are one of the most important game species in extensively managed Mediterranean agro-forest systems. Population declines have led to management to increase their populations. This includes the creation of game crops, but their efficacy for red-legged partridges has not been tested. We developed in October 1996 an experimental introduction of 32 100 × 8 m plots in a 6.46-km mixed agro-forest system area in Portugal. These plots were planted with either lupin Lupinus sp., vetch Vicea sp. or triticale Triticum aestivum × Secale cereale. The main goal of this study was the evaluation of the potential effect of game crops on partridge distribution and productivity, after controlling for the effect of habitat or other management actions. Partridge abundance and distribution were assessed during spring and summer 1997 by intensive territory mapping. We compared characteristics of territory centres with those of random points in relation to land uses, game crops, and location of water points or supplementary grain sites. The most important variable explaining partridge’s location in spring was the density of supplementary water points. In summer, partridge territories were positively associated with the density of water points and lupin game crops, as well as olive trees. Productivity (number of young per territory in relation to adults observed) increased with the density of lupin game crops, but decreased with density of water points and vetch game crops and proportion of woodland within the territories. Overall, this study suggests that management for partridges in areas of agricultural abandonment, such as those in Mediterranean woodlands, would benefit from the introduction of leguminous game crops and water provision, though more studies are required for a more adequate optimization of these measures of habitat improvement, in particular about the specific cover of the crops and their spatial distribution so they provide adequate resources in summer for nestlings.We gratefully acknowledge the financial support provided by ESAB and INIA through the project PAMAF-4030. This project was funded by Portuguese Foundation of Science and Technology (FCT) through the project PRAXIS/PCNA/C/BIA/105/96 and by the Portuguese Ministry of Education and Science and the European Social Fund, through FCT, under POPH - QREN - Typology 4.1, through the grant SFRH/BPD/93079/2013 (LR).Peer Reviewe

Potential welfare issues of the Siamese fighting fish (Betta splendens) at the retailer and in the hobbyist aquarium

Betta splendens is an extremely popular ornamental fish among hobby aquarists. It has an interesting behavioral repertoire, particularly where male aggression and territoriality are concerned. The lack of scientific studies investigating optimal housing conditions in combination with the wide variety of commercially available husbandry products, raises questions about the welfare status of these fish in captivity. In this article, an overview of the available literature on the biology of the betta and general considerations of ornamental fish keeping is given, and environment- and animal-related factors with potential impact on the welfare of Betta splendens are examined. Although more research using biological and physiological indicators is needed, the following factors constituting welfare problems have been identified: an aquarium of limited dimensions, prevalence of Mycobacterium spp. infection, aggression to and from conspecifics or other species in the same aquarium and the limited ability to escape, potential for stress due to prolonged visual contact between males in shops and during shows, and the lack of environmental enrichment in the form of sheltering vegetation

Personal reflections on Gary Bortolotti's links with Spain

Letter.Peer reviewe