Search

Studies on brood desertion in birds have been mainly conducted on species with biparental care, and less often on uniparental species. Females of many duck species remain with their ducklings, unassisted by males, during variable periods of time before the chicks can fledge. In this paper, we examined factors that influence brood desertion by female red-crested pochards ( Netta rufina), common pochards ( Aythya ferina) and white-headed ducks ( Oxyura leucocephala) during a 10-year period in lakes in southern Spain that experienced interannual variations in water levels. At an interspecific level, we found that brood desertion was less frequent in the species that nested earlier (red-crested pochard), while it was more frequent in the species that nested later (white-headed duck). Larger (older) ducklings were deserted more frequently than smaller ones in the three species. However, an interaction between flooding conditions in wetlands and species identity on brood desertion, after accounting for chick age, suggests that there were variations between the ducklings of the three species in their requirements for maternal care, conditioned by environmental conditions. Therefore, our study indicates that environmental conditions may affect parental care. A longer duration of brood attendance by female ducks may buffer against adverse effects of environmental conditions.

Greater flamingos use cosmetic coloration by spreading uropygial secretions pigmented with carotenoids over their feathers, which makes the plumage redder. Because flamingos inhabit open environments that receive direct solar radiation during daytime, and carotenoids bleach when exposed to solar radiation, we expected that the plumage color would fade if there is no maintenance for cosmetic purposes. Here, we show that the concentrations of pigments inside feathers and on the surface of feathers were correlated, as well as that there was a correlation between the concentrations of pigments in the uropygial secretions and on the surface of feathers. There was fading in color (becoming less red) in feathers that received direct solar radiation when there was no plumage maintenance, but not so in others maintained in darkness. When we controlled for the initial color of feathers, the feathers of those individuals with higher concentration of pigments on the feather surfaces were those that lost less coloration after experimental exposure of feathers to sunny conditions. These results indicate that exposure to sunlight is correlated with the fading of feather color, which suggests that individuals need to regularly apply makeup to be more colorful. These results also reinforce the view that these birds use cosmetic coloration as a signal amplifier of plumage color. This may be important in species using highly variable habitats, such as wetlands, since the conditions experienced when molting may differ from those when the signal should be functional, usually months after molting., Greater flamingo plumage coloration fades when there is no frequent application of cosmetics.

Se analiza la Teoría del Rizoma propuesta por Gilles Deleuze y Felix Guattari para identificar elementos conceptuales que permitan fundamentar una metodología de clasificación de documentos producidos en entornos abiertos y plurales, tales como los movimientos sociales. Se enfatiza que la producción de documentos lleva a la producción de relaciones sociales. Esa dimensión social se analiza con ayuda de los conceptos de “refuncionalización” (Umfunktionierung) de Walter Benjamin y de “objeto fronterizo” (Boundary Object) de Susan Star y James Greiseimer. Se comparan las características que el documento adquiere en el proceso de producción literaria planteado por Benjamin y de creación de entornos colaborativos expuesto por Star y Greiseimer con el documento propuesto por Miguel Ángel Rendón Rojas dentro de la Ciencia de la Información Documental. Por último, se identifica al metadato y al hipertexto como los elementos que cumplen con los requerimientos para establecer una metodología de clasificación de documentos producidos en entornos abiertos y cambiantes siguiendo los principios rizomáticos.

Se analizan las discusiones que tuvieron lugar en las revistas American Archivist y Archivaria entre 1982 y 1999 que reflejan las luchas de la Archivística por su identidad como ciencia autónoma. Es posible identificar tres movimientos epistemológicos. El primero apunta la teoría como obstáculo, critica la ineficacia de las generalizaciones científicas, su búsqueda revela más una necesidad del reconocimiento social de la profesión. El segundo se refiere a la teoría como fundamento de cientificidad, que reconoce propiedades esenciales ligadas a la naturaleza de su objeto de estudio y la necesidad de estudiarlas y protegerlas. El último aborda la teoría como transgresión, es decir, como una herramienta de transformación que debe producir cambios indispensables en el desarrollo del campo y considerarla como una forma de liberar las restricciones impuestas por la tradición.

Phenotypic plasticity allows organisms to improve the match between their phenotype and heterogeneous environments. Theoretical models have argued that costs of maintaining the sensory and response machinery necessary for adaptive phenotypic plasticity are important determinants to the evolution of plasticity. Despite recurrent arguments invoking putative metabolic costs associated with maintenance of cellular machinery, no studies have yet attempted to quantify it from a molecular standpoint. Here we experimentally examine physiological differences across genotypes (sibships) of spadefoot toad larvae with different degrees of plasticity in response to predator cues. We observed marked differences across sibships in developmental, growth and morphological responses to predators, and tested whether increased plasticity was associated with oxidative stress or immune suppression. We observed that more plastic sibships experienced higher antioxidant enzymatic activity when reared in the absence of predator cues, i.e. not expressing their plastic responses. The degree of plasticity was also associated with higher lipid peroxidation and slightly greater granulocyte-to-lymphocyte ratio. Higher antioxidant activity in highly plastic sibships suggests that maintenance of phenotypic plasticity may be linked to energy demanding metabolic processes. Our findings suggest that having the potential to produce plastic responses may incur oxidative and immunological costs. In the long term, such maintenance costs may erode individual fitness and even constrain the evolution of plasticity. To our knowledge, this is the first empirical evidence indicating the existence of a physiological cost to the maintenance of phenotypic plasticity., This study was funded by Ministerio de Economía y Competitividad (grants CGL2012-40044 and CGL2014-59206-P). PB was supported by fellowship F.P.U.-AP2010-5373 from the Ministerio de Educación and by a Marie Curie Fellowship METAGE-797879. Laboratory facilities were provided by ICTS-RBD.

Quail eggs have been widely used in field experiments, mainly to study factors associated with the risk of nest predation. Some shortcomings of using quail eggs in this type of study have been previously addressed (e.g., these eggs might be too big for some predators of eggs of small birds). Here, we show experimental evidence of another shortcoming of the use of these eggs in field experiments. Quail eggs exposed to sunlight rapidly faded in colour after three days, both in the visible and UV spectra, and this change was related to the amount of solar radiation received. This caused changes in the camouflage of the eggs, which may be perceived by predators with different visual systems (dichromatic, trichromatic, and tetrachromatic (for both violet- and UV-sensitive species)). Therefore, the results of field studies of nest predation using quail eggs might be questioned in those cases in which the camouflage has been altered due to the rapid changes in coloration, as this can affect the resulting predation rates. We recommend that researchers planning to use quail eggs should perform a prospective assessment of changes in coloration of eggs exposed to environmental conditions in the nest sites used by the target species., This study was funded by grant CGL2017-83518-P from Ministerio de Economia, Industria y Competitividad, Spain, with EU-ERDF financial support. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.

El presente trabajo revela diferentes criterios y metodologías para el ejercicio de evaluación de proyectos de gestión ambiental. Aunado a la carencia de instrumentos de evaluación que incorporen indicadores de impacto de la dimensión biocultural, se constata la tendencia a privilegiar una valoración mercantilista de proyectos, incidiendo en la gestión ambiental. Con el apoyo teórico de la valoración relacional (relational values) y a través de la categorización de códigos emergentes de datos recabados a través de métodos etnográficos, el presente trabajo concluye con una propuesta para la aplicación de indicadores para conocer la incidencia en la dimensión biocultural en el caso de proyectos para el rescate de la meliponicultura, es decir, el cultivo de la abeja nativa comúnmente conocida como abeja melipona o Xunancab (en Maya) (Melipona beecheii), en la península de Yucatán. The present work reveals different criteria and methodologies for the exercise of the evaluation of environmental management projects. Together with the lack of evaluation instruments that incorporate impact indicators of the biocultural dimension, the tendency to privilege a mercantilist valuation of projects, with emphasis on environmental management, is confirmed. With the theoretical support of relational values and through the categorization of emerging codes from data collected through ethnographic methods, this work concludes with a proposal for the application of indicators to know the impact on the biocultural dimension in the case of projects to rescue meliponiculture, that is, the cultivation of the native bee commonly known as melipona bee or Xunancab (in Maya) (Melipona beecheii), in the Yucatan peninsula. O presente trabalho revela diferentes critérios e metodologias para o exercício de avaliação de projetos de gestão ambiental. Adicionado à carência de instrumentos de avaliação que incorpora indicadores de impacto da dimensão biocultural, se constata a tendência de privilegiar uma avaliação mercantilista de projetos, incidindo na gestão ambiental. Com o apoio teórico da valoração relacional (relational values), e por meio da categorização de códigos emergentes de dados recuperados por métodos etnográficos, o presente trabalho conclui com uma proposta para aplicação de indicadores para conhecer a incidência da dimensão biocultural no caso de projetos para o resgate da meliponicultura, quer dizer, o cultivo da abelha nativa comumente conhecida como abelha melipona ou Xunancab (em Maya) (Melipona beecheii), na península de Yucatán.

Amphibian larvae are plastic organisms that can adjust their growth and developmental rates to local environmental conditions. The consequences of such developmental alterations have been studied in detail, both at the phenotypic and physiological levels. While largely unknown, it is of great importance to assess how developmental alterations afect the pigmentation pattern of the resulting metamorphs, because pigmentation is relevant for communication, mate choice, and camoufage and hence infuences the overall ftness of the toads. Here we quantify the variation in several aspects of the pigmentation pattern of juvenile spadefoot toads experimentally induced to accelerate their larval development in response to decreased water level. It is known that induced developmental acceleration comes at the cost of reduced size at metamorphosis, higher metabolic rate, and increased oxidative stress. In this study, we show that spadefoot toads undergoing developmental acceleration metamorphosed with a less complex, more homogeneous, darker dorsal pattern consisting of continuous blotches, compared to the more contrasted pattern with segregated blotches and higher fractal dimension in normally developing individuals, and at a smaller size. We also observed a marked efect of population of origin in the complexity of the pigmentation pattern. Complexity of the postmetamorphic dorsal pigmentation could therefore be linked to pre-metamorphic larval growth and development.

Hunting is an activity that mankind has developed since its emergence as a species. At present, there is a conjunction between local knowledge with respect to hunters’ prey, such as the habitat they occupy, breeding seasons, and even eating habits. Added to this is the social and cultural part of the hunt, represented by the types of hunting that can be practiced, the age to start hunting, the links that can be established between hunters, the hunting rituals performed pre- and post hunting, and the legends and myths around the activity.

Vazquez, L.A., Rendon, M.A., Diaz-Paniagua, C., Gomez-Mestre, I. 2017. Among-species variation in the morphological responses of larval amphibians to native and invasive species. Ecosistemas 26(3): 32-38. Doi.: 10.7818/ECOS.2017.26-3.05 Amphibian larvae are common prey to various types of predators, according to the type of aquatic system they develop in. When they detect water-borne chemical cues from predators (kairomones), amphibian larvae often produce inducible defenses. An important component of such defenses is the alteration of the shape of the larvae, which often consists in producing rounder bodies, shorter tails and deeper tail fins in the presence of predators. However, the activation of these inducible defenses critically depends on the accurate recognition of predator cues. In that context, the human introduction of alien predators with whom local prey species have not shared a joint evolutionary history may pose a grave threat in part because the native prey may fail to recognize the cues of the novel predators and hence fail to trigger the corresponding antipredator phenotype. In this study we analyze the morphological responses of larvae of four amphibian species to two different types of predators: native dragonfly larvae and introduced red-swamp crayfish. We find that three out of the four species readily respond altering their morphology to the presence of dragonflies, but they all fail to respond to introduced crayfish. Moreover, the effect size of the morphological response seems to be congruent with the duration of the larval period of each species so that faster developing species show lesser responses to dragonflies whereas slower developing species show greater responses to them. This is congruent with faster developing species occupying temporary or even ephemeral ponds which typically have lower predator abundance.

Organisms are exposed to multiple environmental factors simultaneously to which they often respond behaviorally, morphologically and/or physiologically. Amphibian larvae are quite plastic and efficiently adjust their phenotype and physiology to the reigning local conditions. Here we tested whether the combination of predator presence and low water pH induces alterations in the morphology and physiology of spadefoot toad tadpoles. We raised Pelobates cultripes tadpoles in the laboratory in water at either pH 4 or 7, and in the presence or absence of caged dragonfly nymphs, and determined their changes in shape through geometric morphometrics to assess whether predator recognition was impaired or not at low pH. We also measured levels of plasma corticosterone, activity of four antioxidant enzymes, as well as markers of oxidative damage and redox status. We found that tadpoles altered their body shape in response to predator cues even at low pH, indicating that predator recognition was not interfered by water acidity and developmental responses were robust even under abiotic stress. Water acidity was associated with increased corticosterone levels in tadpoles, whereas predator presence consistently reduced corticosterone levels. Predator presence was linked to reduced antioxidant enzyme activity, whereas the combination of both factors resulted in negative synergistic effects on lipid peroxidation and the antioxidant capacity of tadpoles. Here we show that tadpoles detect predators even at low pH but that the development of adaptive anti-predatory morphology can magnify physiological imbalances when other stressors co-occur. These results emphasize the need to understand how multiple environmental perturbations can affect animal homeostasis.

En nuestro país como en todo el mundo, hay distintas formas de presentar un libro.Algunas combinan amenidad y tedio; mientras otras, son sólo amenas, o solo tediosas. La mía solo pretende ser una modesta introducción para lo que siempre resulta lo más importante en estos eventos, que es, la intervención del autor cuya obra se presenta. Gracias por asistir a la presentación del libro "D E R E C H O A D M I N I S T R A T I V O" cuya autoría es del reconocido Jurisconsulto Dr. José Roldán Xopa - a quien le expreso la más cordial de las bienvenidas.

The effects of producer diversity on predators have received little attention in arboreal plant communities, particularly in the tropics. This is particularly true in the case of tree diversity effects on web-building spiders, one of the most important groups of invertebrate predators in terrestrial plant communities. We evaluated the effects of tree species diversity on the community of weaver spiders associated with big-leaf mahogany (Swietenia macrophylla) in 19, 21 × 21-m plots (64 plants/plot) of a tropical forest plantation which were either mahogany monocultures (12 plots) or polycultures (seven plots) that included mahogany and three other tree species. We conducted two surveys of weaver spiders on mahogany trees to evaluate the effects of tree diversity on spider abundance, species richness, diversity, and species composition associated with mahogany. Our results indicated that tree species mixtures exhibited significantly greater spider abundance, species richness, and diversity, as well as differences in spider species composition relative to monocultures. These results could be due to species polycultures providing a broader range of microhabitat conditions favoring spider species with different habitat requirements, a greater availability of web-building sites, or due to increased diversity or abundance of prey. Accordingly, these results emphasize the importance of mixed forest plantations for boosting predator abundance and diversity and potentially enhancing herbivore pest suppression. Future work is necessary to determine the specific mechanisms underlying these patterns as well as the top-down effects of increased spider abundance and species richness on herbivore abundance and damage.

Colourful plumage is typical of males in species with conventional sex roles, in which females care for offspring and males compete for females, as well as in many monogamous species in which both sexes care for offspring. Reversed sexual dichromatism—more colourful females than males—is predominant in species with sex role reversal. In the latter species, males care for offspring and females compete for mates, the mating system is mainly polyandrous and there is reversed size dimorphism—females are larger than males. Here, we document a case of reversed dichromatism, in the greater flamingo Phoenicopterus roseus, in which there is no sex role reversal and no reversed size dimorphism. Although theoretical models postulate that cases of reversed dichromatism should be rare among monogamous ornamented birds, our findings show that the use of cosmetics might be a mechanism for the occurrence of more ornamented females than males. Indeed, the concentrations of carotenoids in the uropygial secretions used as make-up were higher in females than in males. Apparently, there was a trade-off between coloration and antioxidant defence, as the concentrations of carotenoids in the uropygial secretions were lower during chick provisioning than in other periods, contrary to those in plasma. In this system, the application of make-up would act as a dynamic signal, which would allow a rapid reallocation of resources used for signalling among functions depending on needs. Cases like this may have evolved to signal the ability to provide parental care when females are more physiologically stressed than males.

Solar radiation is an important driver of animal coloration, not only because of the effects of coloration on body temperature but also because coloration may protect from the deleterious effects of UV radiation. Indeed, dark coloration may protect from UV, but may increase the risk of overheating. In addition, the effect of coloration on thermoregulation should change with egg size, as smaller eggs have higher surface-volume ratios and greater convective coefficients than larger eggs, so that small eggs can dissipate heat quickly. We tested whether the reflectance of eggshells, egg spottiness, and egg size of the ground-nesting Kentish plover Charadrius alexandrinus is affected by maximum ambient temperature and solar radiation at breeding sites. We measured reflectance, both in the UV and human visible spectrum, spottiness, and egg size in photographs from a museum collection of plover eggshells. Eggshells of lower reflectance (darker) were found at higher latitudes. However, in southern localities where solar radiation is very high, eggshells are also of dark coloration. Eggshell coloration had no significant relationship with ambient temperature. Spotiness was site-specific. Small eggs tended to be light-colored. Thermal constraints may drive the observed spatial variation in eggshell coloration, which may be lighter in lower latitudes to diminish the risk of overheating as a result of higher levels of solar radiation. However, in southern localities with very high levels of UV radiation, eggshells are of dark coloration likely to protect embryos from more intense UV radiation. Egg size exhibited variation in relation to coloration, likely through the effect of surface area-to- volume ratios on overheating and cooling rates of eggs. Therefore, differential effects of solar radiation on functions of coloration and size of eggshells may shape latitudinal variations in egg appearance in the Kentish plover.

Rural communities immersed in protected natural areas have local ecological knowledge of the species that exist in their environment, which could be closely related to the management that can be provided to the area. In this sense, the involvement of communities is extremely important in conservation, since they are the ones that make use of the natural resources that surround them.

In this paper, we reflect on the local knowledge about the European honey bee Apis mellifera scutellata, namely its biology, behavior, social structure, communication, and the relationships that these organisms maintain with the environment and their natural enemies. We also discuss the impacts that land use has on this economic activity. The empirical knowledge of beekeepers converges quite well with the scientific knowledge concerning this group of organisms. En el presente trabajo se reflexiona acerca del conocimiento local que tienen los apicultores respecto a la abeja europea Apis mellifera scutellata, su biología, comportamiento estructura social, comunicación, la relación que tienen estos organismos con el entorno, sus enemigos naturales e incluso el impacto que tiene el uso del suelo en esta actividad económica. Además de vislumbrar que este conocimiento empírico converge de manera muy acertada con el conocimiento científico que se tiene de este grupo de organismos.

Se presenta un estudio sobre un aspecto de la fundamentacion logica de la Bibliotecologia y Estudios de la Informacion. Por fundamentacion logica se entiende el analisis de las relaciones entre los componentes del aparato teorico de una disciplina. El aspecto que se pretende realizar es el analisis de las relaciones dialecticas entre dichos componentes. Una relacion dialectica es aquella por la cual se infieren unas categorias a partir del analisis de elementos internos y su interrelacion presentes en una categoria inicial. Se parte de una categoria primaria, la cual contiene todos los demas elementos de la estructura teorica de la ciencia. A semejanza de Marx quien en su obra “El Capital” comienza con el concepto “mercancia” para despues inferir la teoria de la economia capitalista, nosotros partimos del concepto “documento” para obtener la teoria de la Bibliotecologia. Finalmente siguiendo el desarrollo dialectico del conocimiento se transita de la categoria inicial como relacion mas simple, a la esencia, despues a la apariencia y finalmente a la realidad. Se propone como esencia de la Bibliotecologia el satisfacer necesidades de informacion documental, como apariencia el servicio que se presta al publico y como realidad a un sistema de informacion concreto. A LOGICA DO SISTEMA CATEGORIAL DA BIBLIOTECONOMIA E ESTUDOS DA INFORMACAO DOCUMENTAL: UMA ANALISE DIALETICA Resumo Apresenta-se estudo de um aspecto da fundamentacao logica da Biblioteconomia e Estudos da Informacao. Por fundamentacao logica entende-se a analise das relacoes entre os componentes do aparato teorico de uma disciplina. O aspecto que se pretende observar compreende a analise das relacoes dialeticas entre esses componentes. A relacao dialetica e aquela pela qual algumas categorias sao inferidas a partir da analise de elementos internos e suas interrelacoes presentes em uma categorizacao inicial. Parte-se de uma categoria principal que contem todos os outros elementos da estrutura teorica da ciencia. Como Marx, que na sua obra “O Capital” comeca com o conceito de "mercadoria" para dai inferir sua teoria da economia capitalista, partimos do conceito de "documento" para chegar a uma teoria da Biblioteconomia. Finalmente, apos o desenvolvimento dialetico do conhecimento, transita-se da categoria incial como a relacao mais simples, a essencia, e dai para a aparencia e, finalmente, para a realidade. Propoe-se como essencia da Biblioteconomia a satisfacao da informacao documental, como aparencia o servico que se presta ao publico e como realidade os sistemas de informacao concretos.

Studies of risk-taking by breeding birds have frequently addressed the effect of brood value on the decisions taken by incubating birds when predators approach their nests. However, leaving eggs unattended during predator disturbance may expose embryos to other potentially harmful factors, to which parent birds should respond when making decisions about when to leave or return to their nest. In this study, we show that diurnal changes in flushing behaviour of incubating terns from nests during predator approach were affected by egg camouflage, the terns allowing a closer approach to individual nests when the eggs appeared better camouflaged. Return times to the nests were affected by ambient temperature, with the terns shortening such times at high ambient temperatures, thus diminishing the risk of egg overheating. As a whole, our results show that the decisions of the birds on when to leave or return to their nests depended on shifting payoffs, as a consequence of diurnal variations in both the thermal risks incurred by embryos and egg crypsis. Environmental costs of risk-taking, such as those considered here, should be addressed in studies of risk-taking by breeding birds. This type of study may have implications for our knowledge of cognitive processes that affect risk-taking. Significance statement: When a predator approaches a nest, the incubating bird has to decide at which moment to leave the nest, which may be affected by environmental factors that may hamper embryo viability. We studied flushing/returning behaviour of incubating little terns Sternula albifrons in response to disturbance and show that risk-taking was affected by the occurrence of simultaneous environmental threats according to shifting fitness payoffs. When the eggs appeared better camouflaged, which usually occurred around midday, the terns allowed closer approach to individual nests. The terns shortened the return to their nests with increasing ambient temperature, which took place at midday. Thus, our results show that, by adjusting their responses to shifting payoffs, the terns modulated the risks incurred by their offspring, as eggs were less time exposed to direct solar radiation in midday, when the risk of overheating was higher.

Summary 1. Understanding the impact of environmental variability on migrating species requires the estimation of sequential abiotic effects in different geographic areas across the life cycle. For instance, waterfowl (ducks, geese and swans) usually breed widely dispersed throughout their breeding range and gather in large numbers in their wintering headquarters, but there is a lack of knowledge on the effects of the sequential environmental conditions experienced by migrating birds on the long-term community dynamics at their wintering sites. 2. Here, we analyse multidecadal time-series data of 10 waterfowl species wintering in the Guadalquivir Marshes (SW Spain), the single most important wintering site for waterfowl breeding in Europe. We use a multivariate state-space approach to estimate the effects of biotic interactions, local environmental forcing during winter and large-scale climate during breeding and migration on wintering multispecies abundance fluctuations, while accounting for partial observability (observation error and missing data) in both population and environmental data. 3. The joint effect of local weather and large-scale climate explained 31·6% of variance at the community level, while the variability explained by interspecific interactions was negligible (

Capital breeding refers to a strategy in which birds use body stores for egg formation, whereas income breeders obtain all resources for egg formation at breeding sites. Capital breeding should occur more in large-bodied species because the relative cost of carrying stores for egg formation becomes smaller with increasing body size. Based on a comparison between stable isotopes of carbon and nitrogen in potential prey at wintering sites and eggs, we examined whether greater flamingos use nutrients stored earlier in the year for egg production. Our results suggest that the greater flamingo is a partial income breeder, since prey for egg formation were obtained both in overwintering sites and at the breeding site. This may be because there are selective pressures for nesting females to lay soon after arriving at the breeding site, which may be facilitated by arriving at the breeding site with developed ovarian follicles. © 2011 The Authors.

It was long thought that the colour of bird feathers does not change after plumage moult. However, there is increasing evidence that the colour of feathers may change due to abrasion, photochemical change and staining, either accidental or deliberate. The coloration of plumage due to deliberate staining, i. e. with cosmetic purposes, may help individuals to communicate their quality to conspecifics. The presence of carotenoids in preen oils has been previously only suggested, and here we confirm for the first time its presence in such oils. Moreover, the carotenoids in the uropygial secretions were the same specific pigments found in feathers. We show not only that the colour of feathers of greater flamingos Phoenicopterus roseus became more colourful due to the application of carotenoids from uropygial secretions over the plumage but also that the feathers became more colourful with the quantity of pigments applied over them, thus providing evidence of cosmetic coloration. Flamingos used uropygial secretions as cosmetic much more frequently during periods when they were displaying in groups than during the rest of the year, suggesting that the primary function of cosmetic coloration is mate choice. Individuals with more colourful plumage initiated nesting earlier. There was a correlation between plumage coloration before and after removal of uropygial secretions from feathers' surfaces, suggesting that the use of these pigmented secretions may function as a signal amplifier by increasing the perceptibility of plumage colour, and hence of individual quality. As the cosmetic coloration strengthens signal intensity by reinforcing base-plumage colour, its use may help to the understanding of selection for signal efficacy by making interindividual differences more apparent. © 2010 Springer-Verlag., Funding was provided by Ministerio de Educación y Ciencia of Spain with EU–ERDF support (research grants BOS2002-04695 and CGL2005-01136/BOS).

This essay departs from the assumption that a science develops according to a paradigm, in other words, that it develops within a general framework accepted by the scientific community. Therefore, we examine the possibility that, in today's society, the values of social and political actions that are recognized in the declarations of international organizations and national associations, in the theorists' writings of the informative documentary area, and in teaching materials contained in curricula, are values that also form the library paradigm. Based on this assumption, we analyze both, contemporary society as an information society, and the political and social values that appear in documents of different institutions, and in studies of the library sphere. The conclusion is that such values, rather than belonging to the library paradigm, derive from the ontological structure of the human being. Este estudio, partiendo de la idea de que una ciencia se desarrolla dentro de un paradigma, o sea, de un marco general aceptado por la comunidad científica, analiza la posibilidad de que, en la sociedad contemporánea, los valores de acción social y política reconocidos en declaraciones de organismos internacionales y asociaciones nacionales, en documentos teóricos del área informativa documental, y en la materia de enseñanza comprendida en planes de estudio, formen parte de un paradigma bibliotecológico. Desde esta suposición, se discute el tipo de sociedad contemporánea como sociedad de la información, se identifican los valores sociales y políticos que aparecen en documentos de distintas instituciones y en estudios en la esfera bibliotecológica, y se concluye que dichos valores, más que pertenecer al paradigma bibliotecológico, emanan de la propia estructura ontológica del ser humano.

Background Currently available antiarrhythmic agents for the treatment of atrial fibrillation (AF) have important limitations, leaving an unmet need for safe and effective therapy. Ranolazine is an approved antianginal agent with a favorable safety profile and electrophysiologic properties suggesting a potential role in the treatment of AF. Objective The purpose of this study was to assess the safety and efficacy of ranolazine in the prevention of AF recurrence after successful electrical cardioversion and to ascertain the most appropriate dose of this agent. Methods This prospective, multicenter, randomized, double-blind, placebo-control parallel group phase II dose-ranging trial randomized patients with persistent AF (7 days to 6 months) 2 hours after successful electrical cardioversion to placebo, or ranolazine 375 mg, 500 mg, or 750 mg bid. Patients were monitored daily by transtelephonic ECG. The primary end-point was the time to first AF recurrence. Results Of 241 patients randomized, 238 took at least 1 drug dose. Ranolazine proved to be safe and tolerable. No dose of the drug significantly prolonged time to AF recurrence. AF recurred in 56.4%, 56.9%, 41.7%, and 39.7% of patients in the placebo, ranolazine 375 mg, ranolazine 500 mg, and ranolazine 750 mg groups, respectively. The reduction in overall AF recurrence in the combined 500-mg and 750-mg groups was of borderline significance compared to the placebo group (P = .053) and significant compared to 375-mg group (P = .035). Conclusion No dose of ranolazine significantly prolonged time to AF recurrence. However, the 500-mg and 750 mg-groups combined reduced AF recurrences, suggesting a possible role for this agent in the treatment of AF.

This paper presents an assessment of spider diversity in a complex landscape of southern Mexico. Eighteen different habitats were identified, measured and mapped across this fragmented landscape. Habitat types were characterized by measuring various features, including number of plant forms, tree cover and litter depth. Each month from February to April (dry season) and from June to August 2002 (wet season), spiders were sampled on each habitat by using pitfall traps and direct collection. Correlations between spider diversity and habitat characteristics were carried out to explore the relative contribution of each habitat variable as related to changes in spider composition and richness. In total, 115 spider species were recorded in 18 habitat types, and the mean number and density of species per habitat were 21 (± 3, standard error of mean) and 57 (± 9), respectively. The species recorded represent 41% of the fauna recorded in the Mexican state of Chiapas and 4% of the fauna recorded in Mexico. Relatively pristine habitats (e.g. deciduous forest) contained an important proportion of spider diversity in this fragmented landscape. Epigean spider diversity was significantly correlated with tree cover and with the diversity of plant forms during the rainy season. No correlation was detected between soil spider diversity and the habitat variables measured for any season. The results of this work suggest that in highly fragmented tropical landscapes, some habitat types (e.g. coffee plantations, hedgerows) might play an important role for the persistence of spider populations. The prevalence of relatively stable conditions in some of these habitats can allow spiders species (e.g. Nephila clavipes) to overcome adverse conditions such as a decrease in humidity and dramatic changes in temperature and wind exposure, allowing them to recolonize when favourable conditions return.

Introduccion : Informacion y ser humano son dos realidades inseparables que no pueden existir la una sin la otra. Por un lado, decir “informacion” implica reconocer un ser humano que la creo; y por otro lado, el estar frente a un ser humano presupone la existencia de informaciones gracias a las cuales se forma, se comunica y vive en sociedad. Dicha unidad: informacion-ser humano se manifiesta como una realidad ontologica: el ser informacional. Ante esa interdependencia surge la inquietud de analizar como aparece filosoficamente la relacion informacion-desarrollo humano desde una optica holistica y dialectica. Objetivo : El trabajo busca explicar y comprender el proceso por el cual el ser humano, visto como ser informacional, atraviesa diversas etapas en su devenir dialectico hasta alcanzar su autoconocimiento. Metodologia : Nuestro estudio empleo basicamente el metodo dialectico, el cual reconoce la interdependencia de los opuestos sin privilegiar o menospreciar alguno de ellos, y contempla la realidad como algo siempre dinamico. Asimismo, se utilizo la investigacion documental para identificar autores y trabajos que analizaron la problematica. Simultaneamente se recurrio al metodo hermeneutico para interpretar los textos consultados y establecer un dialogo con las propuestas de los pensadores que nos sirvieron de referentes teoricos. El metodo de analisis y sintesis fue otra herramienta metodologica de la que nos valimos y finalmente el metodo deductivo nos fue util para realizar las inferencias logicas necesarias para obtener nuestras conclusiones debidamente fundamentadas. En un inicio se analizan las nociones de dialectica e informacion y en un segundo momento se aplican esos conceptos en el analisis del desarrollo humano desde el punto de vista de ser informacional. Resultados : El estudio nos mostro la necesidad de emplear una dialectica distinta a la hegeliana donde no se resuelvan las contradicciones en una sintesis superior, sino donde se conserve la tension de manera permanente. Como consecuencia de lo anterior, no existe una direccionalidad y termino del movimiento. Se descubrio que los momentos de la dialectica: ser en si, ser fuera de si, ser para si, aparecen en el movimiento del ser informacional como sujeto que construye informacion ideal, documentos como objetivacion de la informacion, reconstruccion de la informacion en su naturaleza ideal al consultar los documentos. Conclusiones : Se concluye que la informacion es un agente indispensable para el proceso de formacion del ser del ser humano, y en la esfera informativo-documental convergen la ontologia, la gnoseologia, la antropologia y lo social.

We documented the presence and abundance of spider species (Arachnida: Araneae) on young trees of Swietenia macrophylla, Ceiba pentandra and Cordia dodecandra found in an experimental plantation. Surveys of spider abundance and species identity conducted twice during the growing season indicated marked differences in web-building spider assemblages associated with each tree species. Swietenia exhibited the lowest spider abundance, whereas Cordia and Ceiba had similarly higher abundances. Leucauge venusta (Walckenaer, 1841) was the dominant spider on all tree species, but different spider species were co-dominant on Cordia and Ceiba (Araneus pegnia (Walckenaer, 1841) and Argiope argentata (Fabricius, 1775) respectively), and several spider species were exclusive to each tree species. These results highlight the influence of tree species identity on community structure at higher trophic levels, particularly in the case of web-building spiders inhabiting tropical tree communities.

In sexually dimorphic species, the parental effort of the smaller sex may be reduced due to competitive exclusion in the feeding areas by the larger sex or physiological constraints. However, to determine gender effects on provisioning patterns, other intrinsic and extrinsic factors affecting parental effort should be accounted for. Greater flamingos (Phoenicopterus roseus) exhibit sexual size dimorphism. In Fuente de Piedra colony, the lake dries out almost completely during the breeding season and both parents commute between breeding and foraging sites >130 km away during the chick-rearing period. Applying multistate capture–recapture models to daily observations of marked parents, we determined the effects of sex, and their interactions with other intrinsic and extrinsic factors, on the probability of chick desertion and sojourn in the colony and feeding areas. Moreover, using stable isotopes in the secretions that parents produce to feed their chicks, we evaluated sex-specific use of wetlands. The probability of chick attendance (complementary to chick desertion) was >0·98. Chick desertion was independent of parental sex, but decreased with parental age. Females stayed in the feeding areas for shorter periods [mean: 7·5 (95% CI: 6·0–9·4) days] than males [9·2 (7·3–11·8) days]. Isotopic signatures of secretions did not show sex differences in δ13C, but males' secretions were enriched in δ15N, suggesting they fed on prey of higher trophic levels than females. Both parents spent approximately 1 day in the colony, but females prolonged their mean stay when the lake dried out. Females also allocated more time to foraging in the flooded areas remaining in the colony, likely because they were energetically more stressed than males. The results indicate that sex-specific provisioning behaviour in greater flamingo is related to differential effects of both intrinsic and extrinsic factors. Males seem forage less efficiently than females, whereas females' body condition seems to be lower after feeding the chick. Our methodology may be extended to species that feed on distant food sources and that do not visit their offspring daily, to elucidate patterns of chick-provisioning behaviour.

In a previous survey of otters (Lutra lutra L. 1758) in Spain, different causes were invoked to explain the frequency of the species in each province. To find common causes of the distribution of the otter in Spain, we recorded a number of spatial, environmental and human variables in each Spanish province. We then performed a stepwise linear multiple regression of the proportion of positive sites of otter in the Spanish provinces separately on each of the three groups of variables. Geographic longitude, January air humidity, soil permeability and highway density were the variables selected. A linear regression of the proportion of otter presence on these variables explained 62.4% of the variance. We then used the selected variables in a partial regression analysis to specify which proportions of the variation are explained exclusively by spatial, environmental and human factors, and which proportions are attributable to interactions between these components. Pure environmental effects accounted for only 5.5% of the variation, while pure spatial and pure human effects explained 18% and 9.7%, respectively. Shared variation among the components totalled 29.2%, of which 10.9% was explained by the interaction between environmental and spatial factors. Human factors explained globally less variance than spatial and environmental ones, but the pure human influence was higher than the pure environmental one. We concluded that most of the variation in the proportion of occurrences of otter in Spanish provinces is spatially structured, and that environmental factors have more influence on otter presence than human ones; however, the human influence on otter distribution is less structured in space, and thus can be more disruptive. This effect of large infrastructures on wild populations must be taken into account when planning large-scale conservation policies.

Se analiza la actividad informativa documental, que incluye las actividades bibliotecaria y archivística, en diferentes épocas de la historia de la humanidad; se describen los valores específicos que tuvieron lugar en cada uno de ellas, así como los que lograron prevalecer en el devenir histórico de dicha actividad. Con ello se muestra una unidad axiológica continua-discontinua, la cual descarta rompimientos absolutos paradigmáticos, relativismos absolutos, o una quietud absoluta sin transformaciones axiológicas. El pasado, el presente y el futuro son momentos distintos, cada uno con un contexto, condiciones y circunstancias específicas propias; pero al mismo tiempo es posible descubrir un eje transversal que bajo diferentes apariencias se va manifestando