37 research outputs found

    Sexual selection in the Swallow Hirundo rustica - A review

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    Darwinian theory of sexual selection and its development up to the present state of knowledge are sketched. The most important results of empirical studies on sexual selection in the Swallow Hirundo rustica are reviewed. The Swallow is a socially monogamous, slightly sexually dimorphic avian species. Long tail streamers are considered as sexual ornaments of males. Female preference for long and symmetric male tails has been inferred on both observational and experimental grounds. Experimental elongation of the tail causes short-term benefits and long-term costs in male reproductive performance. Behavioural consequences of sexual selection acting in the Swallow are discussed. An aerodynamic role of male tail streamers is also considered.Zadanie pt. „Digitalizacja i udostępnienie w Cyfrowym Repozytorium Uniwersytetu Łódzkiego kolekcji czasopism naukowych wydawanych przez Uniwersytet Łódzki” nr 885/P-DUN/2014 dofinansowane zostało ze środków MNiSW w ramach działalności upowszechniającej naukę

    Patterns of year-to-year variation in haemoglobin and glucose concentrations in the blood of nestling Pied Flycatchers Ficedula hypoleuca

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    Physiological tools can be used to identify the sources and consequences of stressors on animals. Understanding the influences of variation in habitat quality and anthropogenic disturbance on organism condition and health may improve future management and conservation. We present results concerning variation in haemoglobin and glucose concentrations in the blood of about 14-day-old nestling Pied FlycatchersFicedula hypoleuca in central Poland over a 4-year period, 2011–2014, in a deciduous forest. The most important findings of the study are: (1) the concentration of haemoglobin and glucose of the nestlings from the same brood tended to be consistently similar, with much variation occurring among broods; (2) repeatability of haemoglobin concentration was higher than repeatability of glucose concentration; (3) mean levels of haemoglobin and glucose varied among years; (4) haemoglobin and glucose concentrations were negatively correlated; and (5) there was a positive relationship between haemoglobin levels and breeding success.All procedures were approved by the Local Ethical Committee and the State Office for Environment Protection. We thank A. Jaksa, D. Man´kowska, M. Janiszewska and J. Białek for their help and consent in conducting research in the areas under their administration. The study was founded by a grant from the Polish Ministry of Science and Higher Education No. N N304 045136 and University of Ło´dz´ (No. 506/829). We are obliged to P. Procter for linguistic consultation. We thank both reviewers for their valuable and constructive comments

    Interaction of Climate Change with Effects of Conspecific and Heterospecific Density on Reproduction

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    We studied the relationship between temperature and the coexistence of great titParus majorand blue titCyanistes caeruleus, breeding in 75 study plots across Europe and North Africa. We expected an advance in laying date and a reduction in clutch size during warmer springs as a general response to climate warming and a delay in laying date and a reduction in clutch size during warmer winters due to density-dependent effects. As expected, as spring temperature increases laying date advances and as winter temperature increases clutch size is reduced in both species. Density of great tit affected the relationship between winter temperature and laying date in great and blue tit. Specifically, as density of great tit increased and temperature in winter increased both species started to reproduce later. Density of blue tit affected the relationship between spring temperature and blue and great tit laying date. Thus, both species start to reproduce earlier with increasing spring temperature as density of blue tit increases, which was not an expected outcome, since we expected that increasing spring temperature should advance laying date, while increasing density should delay it cancelling each other out. Climate warming and its interaction with density affects clutch size of great tits but not of blue tits. As predicted, great tit clutch size is reduced more with density of blue tits as temperature in winter increases. The relationship between spring temperature and density on clutch size of great tits depends on whether the increase is in density of great tit or blue tit. Therefore, an increase in temperature negatively affected the coexistence of blue and great tits differently in both species. Thus, blue tit clutch size was unaffected by the interaction effect of density with temperature, while great tit clutch size was affected in multiple ways by these interactions terms.Institute of Biology of Karelian Research Centre 0218-2019-0080Academy of Finland 265859Ministerio de Economía y Competitividad CGL-2016-79568-C3-3-

    Avian Feathers as Bioindicators of the Exposure to Heavy Metal Contamination of Food

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    The aim of this study was to determine the possibility of using feathers of blue tit nestlings to assess the level of endogenous accumulation of lead. For this purpose we conducted an experiment with lead application to randomly chosen nestlings from eight randomly drawn broods. Five days after the exposure, feathers of lead-treated nestlings had significantly higher lead concentrations than control nestlings. This result suggests that feathers can be used as reliable non-destructive bioindicators to assess the level of heavy metals originating from contaminated food, which is of great significance for comparative studies on ecological consequences of pollution

    The effect of climate change on avian offspring production: A global meta-analysis

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    Climate change affects timing of reproduction in many bird species, but few studies have investigated its influence on annual reproductive output. Here, we assess changes in the annual production of young by female breeders in 201 populations of 104 bird species (N = 745,962 clutches) covering all continents between 1970 and 2019. Overall, average offspring production has declined in recent decades, but considerable differences were found among species and populations. A total of 56.7% of populations showed a declining trend in offspring production (significant in 17.4%), whereas 43.3% exhibited an increase (significant in 10.4%). The results show that climatic changes affect offspring production through compounded effects on ecological and life history traits of species. Migratory and larger-bodied species experienced reduced offspring production with increasing temperatures during the chick-rearing period, whereas smaller-bodied, sedentary species tended to produce more offspring. Likewise, multi-brooded species showed increased breeding success with increasing temperatures, whereas rising temperatures were unrelated to repro- ductive success in single-brooded species. Our study suggests that rapid declines in size of bird populations reported by many studies from different parts of the world are driven only to a small degree by changes in the production of young

    Dangers of creationism

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    Although evolution is the most fundamental concept that unifies the entire science of biology, it has repeatably been facing challenges from creationists. While realism and methodological naturalism constitute the minimum assumptions of science, creationism rejects evolution as a natural process in favour of supernatural explanations. Modern creationism has evolved into a variety of different forms, representing a spectrum from young-earth creationism to so called intelligent-design theory. The latter was introduced as a result of conducting the "wedge strategy" of the Discovery Institute. The strategy is aimed at undermining the trust in the methodological naturalism of science, including evolution, and introducing the intelligent design theory to school curricula as an alternative concept. This form of creationism appeared in the US because of unique constitutional circumstances but, afterwards, it has dispersed all over the world, including Poland. A common feature of all forms of creationism is that they deny scientific evidence again and again. They also try to find so called gaps in knowledge and if they can not find ones, they just fabricate them. Their arguments range from extremely naive to more sophisticated, like the concept of "irreducible complexity". No form of creationism has ever produced any positive scientific research programme or any results that could be presented as scientific evidence. Consequently, having no scientific basis for their claims and yet challenging the way evolution is being thought, creationists pose a political, not scientific, threat

    An incorrect analysis of archeozoological data on the aurochs

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    Egg-size variation in Algerian populations of the Blue Tit (Parus caeruleus ultramarinus) : effects of altitude and habitat

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    Egg-size, as a component of life history, is expected to be traded-off with other components and, consequently, to display a pattern of variation between different habitats and altitudes. Relevant data being very scarcely available for just a few bird species caused us to study interhabitat and interaltitude variation in egg dimensions and mass in the Blue Tit Parus caeruleus ultramarinus, taking the advantage of the occurrence of this species in a variety of habitats and at different altitudes in North Africa (north-eastern Algeria). In 1991-1993 we selected 6 study sites representing two types of habitat (rich deciduous forests dominated by Alnus glutinosa and Quercus faginea vs poor evergreen forests of Quercus suber) at three elevations (30 m asl, 500 m als and 900-1 000 m asl). We analysed both multiple response variables characterizing egg dimensions and individual egg traits. Eggs turned out to differ between altitudes (the lowest elevation against the two higher ones) but did not differ between habitats. They also display relatively high within-clutch repeatabilities, 0.6 on average for all traits. Egg traits were not significantly correlated with clutch-size within study stations, but the analysis of a bivariate response variable composed of egg volume and clutch-size suggested that these components of life history were negatively linked. Moreover, this bivariate response variable differed both between habitats and altitudes.La taille de l’œuf est un caractère que l’on s’attend à être lié à d’autres traits d’histoire de la vie de sorte qu’il devrait montrer des variations en fonction de l’habitat et de l’altitude. Fort peu de données probantes étant disponibles et pour un nombre limité d’espèces, nous avons conduit en 1991-93 une étude de la variation interhabitat et altitudinale des dimensions et du poids des œufs de la Mésange bleue Parus caeruleus ultramarinus, profitant de ce que cette espèce se montre dans toute une gamme d’habitats et d’altitudes en Afrique du Nord, notamment dans le nord-est de l’Algérie. Six stations d’étude ont été sélectionnées, représentant deux types d’habitat (les riches forêts caducifoliées dominées par Alnus glutinosa et Quercus faginea opposées aux forêts sempervirentes pauvres de Quercus suber) et trois altitudes (30 m, 500 m et 900-1 000 m). Nous avons analysé à la fois les variables à réponse multiple qui caractérisent les dimensions des œufs et les traits individuels de ces œufs. Les œufs sont apparus différer selon l’altitude (opposition entre le plus bas niveau et les suivants) mais pas selon l’habitat. Ils montrent aussi un relativement fort degré de répétabilité intraponte, de 0,6 en moyenne pour tous les caractères. Ceux-ci n’étaient pas significativement liés à la taille de la ponte dans un même site mais l’analyse d’une variable bivariée intégrant le volume de l’œuf et la taille de la ponte a suggéré que ces deux traits seraient négativement corrélés. De plus, cette variable bivariée différait à la fois d’un habitat et d’une altitude à l’autre.Chabi Yassine, Benyacoub Slim, Bańbura Jerzy. Egg-size variation in Algerian populations of the Blue Tit (Parus caeruleus ultramarinus) : effects of altitude and habitat. In: Revue d'Écologie (La Terre et La Vie), tome 55, n°2, 2000. pp. 183-192
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