12 research outputs found

    Migratory bats are sensitive to magnetic inclination changes during the compass calibration period

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    The Earth's magnetic field is used as a navigational cue by many animals. For mammals, however, there are few data to show that navigation ability relies on sensing the natural magnetic field. In night-time migrating bats, experiments demonstrating a role for the solar azimuth at sunset in the calibration of the orientation system suggest that the magnetic field is a candidate for their compass. Here, we investigated how an altered magnetic field at sunset changes the nocturnal orientation of the bat Pipistrellus pygmaeus. We exposed bats to either the natural magnetic field, a horizontally shifted field (120Ā°), or the same shifted field combined with a reversal of the natural value of inclination (70Ā° to -70Ā°). We later released the bats and found that the take-off orientation differed among all treatments. Bats that were exposed to the 120Ā° shift were unimodally oriented northwards in contrast to controls which exhibited a bimodal north-south distribution. Surprisingly, the orientation of bats exposed to both a 120Ā° shift and reverse inclination was indistinguishable from a uniform distribution. These results suggest that these migratory bats calibrate the magnetic field at sunset, and for the first time, they show that bats are sensitive to the angle of magnetic inclination.</p

    Corncrake conservation genetics at a European scale: the impact of biogeographical and anthropological processes

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    Understanding patterns of genetic structure, gene flow and diversity across a species range is required if we are to determine the genetic status and viability of small peripheral populations. This is especially crucial in species distributed across a large range where spatial heterogeneity makes it difficult to predict the distribution of genetic diversity. Although biogeographical models provide expectations of how spatially structured genetic variation may be at the range scale, human disturbance may cause strong deviations from these theoretical predictions. In this study, we investigated genetic structure and demography at a pan-European scale, in the corncrake Crex crex, a grassland bird species strongly affected by agricultural changes. We assessed population structure and genetic diversity, as well as demographic trends and direction of gene flow, in and among 15 contemporary populations of this species. Analyses revealed low genetic structure across the entire range with high levels of genetic diversity in all sites. However, we found some evidence that the westernmost populations were, to a very limited extent, differentiated from the rest of the European population. Demographic trends showed that population numbers have decreased in western Europe and remained constant across eastern Europe. Results may also suggest asymmetric gene flow from eastern to western populations. In conclusion, we suggest that the most likely scenario is that contrasting demographic regimes between eastern and western populations, driven by heterogeneous human activity, has caused asymmetric gene flow that has buffered small peripheral populations against genetic diversity loss, but also erased any genetic structure that may have existed. Our study highlight the need of coordinated actions at the European scale to preserve source populations and ensure the maintenance of reproductive productivity in the most threatened sites, in order to avoid losing any adaptive potential and too strongly relying on sink source populations whose future is uncertain

    Development of Evidence Institute in Civil Proceedings in Latvia since 1918 and Expressions of Succession

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    Oskars KeiÅ”s, maÄ£istra darbs ā€žPierādÄ«jumu institÅ«ta civilprocesā attÄ«stÄ«ba Latvijā no 1918.gada un tā pēctecÄ«bas izpausmesā€. MaÄ£istra darba mērÄ·is ā€“ izskatÄ«t un analizēt pierādÄ«jumu institÅ«tu civilprocesā, tā pēctecÄ«bu un attÄ«stÄ«bu Latvijā no 1918. gada, tā nozÄ«mi. MaÄ£istra darba uzdevumi - normatÄ«vo aktu un juridiskās literatÅ«ras izpēte un analÄ«ze, tiesas spriedumu izpildes nozÄ«mes un bÅ«tÄ«bas raksturojums, vēsturiskās attÄ«stÄ«bas izpētÄ«Å”ana, priekÅ”likumu izteikÅ”ana. MaÄ£istra darbā izmantotās zinātniski pētnieciskās metodes ā€“ komparatÄ«vā, teleoloÄ£iskā, sistēmanalÄ«zes, vispārināŔana. MaÄ£istra darbs sastāv no četrām daļām, kurās tiek apskatÄ«ts pierādÄ«jumu jēdziens civilprocesā, tā pamatprincipi, pierādÄ«jumu nodroÅ”ināŔana, pierādÄ«Å”anas lÄ«dzekļi un izzuduÅ”ie pierādÄ«Å”anas lÄ«dzekļi MaÄ£istra darba rezultātā ir atrasta pierādÄ«jumu institÅ«ta civilprocesā regulējoÅ”o normu kontinuitāte, atŔķirÄ«bas un attÄ«stÄ«bas kopējās tendences. Nobeigumā izveidots kopsavilkums, darba izstrādāŔanas procesā izmantoti normatÄ«vie akti, literatÅ«ra un tiesu prakses materiāli.Oskars KeiÅ”s, masterā€™s thesis ā€œDevelopment of Evidence Institute in Civil Proceedings in Latvia since 1918 and Expressions of Successionā€. The goals of masterā€™s thesis ā€“ review and analyze development of evidence institute in civil proceedings and expressions of succession in Latvia since 1918, find its significance. The tasks of masterā€™s thesis ā€“ research and analysis of legislation and cases, description and finding essence of judgment execution, research of historical development, giving of proposals. The scientific research methods used in masterā€™s thesis ā€“ comparative, teleological, system analytic, generalization. Master's thesis consists of four parts, looking at the concept of evidence in civil proceedings, its principles, providing of evidences, means of evidences and extinct means of evidences. Continuity of legislation, diversity and common development trends has been found by masterā€™s thesis. Summary, the list of sources and literature, and cases used in the masterā€™s thesis are included at the end of the masterā€™s thesis

    Data from: Diet of the insectivorous bat Pipistrellus nathusii during autumn migration and summer residence

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    Migration is widespread among vertebrates. Yet bat migration has received little attention and only in the recent decades knowledge of it has been gained. Migration can cause significant changes in behaviour and physiology, due to increasing energy demands and aerodynamic constraints. Dietary shifts, for examples, have been shown to occur in birds before onset of migration. For bats it is not known if a change in diet occurs during migration, although especially breeding season related dietary preference has been documented. It is known that fat-rich diets, and subsequent accumulation of high fat deposits, do increase the flight range of migratory bats. Some bat species can be regarded as long-distance migrants, covering up to 2,000 km on their way between summer and winter roosting areas. Pipistrellus nathusii (Vespertilionidae), a European long-distant migrant, travels each year along the Baltic Sea from north-eastern Europe to hibernate in central and southern Europe. This study presents data on the dietary habits of migrating Pipistrellus nathusii compared with dietary habits during the breeding season. We analysed faecal samples from bats on fall migration caught at the Ornithological Field Station in Pape, Latvia and from samples collected in North-Latvian summer roosts. We applied both morphological identification and molecular methods, as morphological methods also recognize life stages of prey and can contribute frequency data. The diets of bats on migration and breeding bats were similar, with Diptera and Lepidoptera comprising the major prey categories. However certain prey groups could be explained by the different hunting habitats used during migration vs. summer residence

    Infection status of corncrake samples

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    Infection status and haemosporidian lineages detected in 354 corncrake (Crex crex) samples collected in 9 populations across Europe

    Sequences of P. nathusii dietary samples

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    Fasta file of seuqences from ion torrent sequencing of faecal samples from P. nathusii, collected in the field
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