48 research outputs found
Wintry distribution patterns and habitat use of Greylag Geese Anser anser in a city in southern Germany
Anders als bei den meisten nordischen wilden Gänsepopulationen konnte bei den verwilderten Graugänsen in Stuttgart bisher kein ausgeprägtes Zugverhalten beobachtet werden. Über ihre Verbreitung im Winter war bisher wenig bekannt. Es wurde daher untersucht, ob winterliche Witterung zu Veränderungen der Verbreitungsmuster und des Habitatgebrauchs dieser sesshaften Gänse führte. Dafür wurden drei Methoden angewandt: (1) Der Bestand der im Winter 2004/05 im Stadtbereich anzutreffenden Gänse wurde wöchentlich erfasst, (2) die Veränderungen der Verbreitungsmuster und der Habitatnutzung anhand von Ringablesungen dokumentiert und (3) Faecestransekte zur Messung der relativen Beweidungsintensität auf verschiedenen Wiesen eingerichtet. Bei den wöchentlichen Zählungen hielten sich zwischen 80 und 159 Graugänse im Untersuchungsgebiet auf. Einige Gänse verließen zeitweise das Stadtgebiet, andere wanderten ein. Die Verteilungsmuster variierten individuell: Während einige Gänse nur wenige Gebiete nutzten, flogen andere weiter umher. Die wöchentliche Beweidungsintensität war am Max- Eyth-See höher als in den städtischen Parks. Bei zugefrorenen Seen suchten viele Gänse das Neckarufer beim Max-Eyth-See auf, das sonst wenig genutzt wurde. Eine weitere Populationszunahme könnte in absehbarer Zeit zu Veränderungen im Verteilungsmuster der Gänse und zur Besiedlung neuer Gebiete im weiteren Umkreis führen.Unlike most wild Nordic goose populations, the feral Greylag Geese in Stuttgart so far do not show marked migratory behaviour. We investigated how wintry weather conditions changed distribution patterns and habitat use of these usually sedentary geese and whether they were forced to switch to snow- and ice-free areas. Th ree diff erent methods were used to investigate this: (1) Th e number of geese present in diff erent areas of the city during winter 2004/05 was recorded, (2) the changes in distribution patterns of ringed individuals noted and (3) faeces transects established on diff erent pastures to measure relative grazing pressure on a weekly basis. During weekly counts 80 - 159 Greylags were recorded throughout the study area indicating temporal immigration and emigration of geese. Distribution patterns showed large individual variation: Whereas some geese used only few areas some others roamed more widely.Weekly grazing intensity at the Max-Eyth-Lake was always higher than within the city. While the lakes were frozen up most geese used habitats along the river Neckar adjacent to the Max-Eyth-Lake. During these periods the river Neckar was the only stretch of open water in the study area and became more important to the geese. A further increase in numbers might change the distribution pattern of the geese and may lead to colonisation of more distant areas in the future
Non-native and naturalized bird species (neozoa) in Germany, part I: occurrence, population size and status
Dies ist der erste Bericht der Projektgruppe Neozoen der DO-G. Er beinhaltet eine Zusammestellung aller bisher bekannt gewordenen Vorkommen von nichtheimischen Vogelarten in Deutschland und fasst unsere Kenntnisse über Auftreten, Brutbestand, Bestandstrend und Status (in definierten Statuskategorien) zusammen. Bis 2007 wurden in Deutschland 341 nichtheimische Vogelarten festgestellt, von denen 251 wohl nicht im Freiland gebrütet haben und nach derzeitigem Kenntnisstand keine biologische Relevanz für die heimischen Artengemeinschaft haben. Andererseits haben 90 Neozoenarten mindestens einmal in Deutschland gebrütet, und ihr derzeitiger Brutstatus wird (+/-) ausführlich beschrieben. Eine Reihe dieser Arten haben sich inzwischen in Deutschland fest etabliert (Kategorie C), weil sie seit mindestens 25 Jahren und mindestens drei Generationen hier brüten (C1); dies sind Kanadagans, Rostgans, Mandarinente, Jagdfasan, Straßentaube und Halsbandsittich. Bei zwei weiteren Arten werden die Kriterien für die Etablierung in wenigen Jahren erfüllt sein: Alexandersittich und Gelbkopfamazone. Bei mehreren Arten existieren neben den Wildvogelpopulationen auch Brutbestände von Neozoen (sowie Mischbestände), u.a. Höckerschwan, Graugans, Weißwangengans und Stockente. Die Nilgans hat den Etablierungsstatus C1 zwar in Deutschland noch nicht erreicht, jedoch in einigen Nachbarländern, und wird daher in der Kategorie C5 als etabliert geführt, bis eine Überführung in Kategorie C1 als voll etabliert im Jahr 2009 möglich ist. Angesichts derzeitiger Entwicklungen in Handel und Haltung exotischer Vögel ist mit einer anhaltenden Zunahme des Auftretens und der Etablierung von Neozoen in unserem Raum zu rechnen.This is the first report of the German Neozoa Working Group (PG Neozoen der DO-G), on the occurrence, status, population size and population trend of all introduced/naturalized species recorded in Germany (and adjacent countries). Up to 2007, 341 introduced bird species have been recorded in Germany, the majority of which do not have any importance with regard to the national avifauna (251 species in status category E3 are “non-breeding”). There are, however, 90 species which have bred in the wild at least once in Germany. Quite a range of introduced species have reached the status of formal establishment (category C) having bred in Germany for at least 25 years and over at least three generations (C1), e.g. Canada Goose, Ruddy Shelduck, Mandarin Duck, Ring-necked Pheasant, Feral Pigeon, and Ring-necked Parakeet; in two more species the criteria for establishment will soon be fulfilled, e.g. Alexandrine Parakeet and Yellow-headed Amazon. At least four species have naturalized populations next to indigenous ones, i.e. Mute Swan, Barnacle Goose, Greylag Goose, and Mallard. One species, the Egyptian Goose, has not yet achieved C1-Status in Germany, but has done so in adjacent countries, thus qualifying for C5 status (until fully established in Germany in 2009). Considering current developments in exotic bird trade and bird keeping, further increases in occurrence and naturalization of neozoan bird species in Germany are to be expected. The consequences of this development will be discussed in later reports
Trait based niche differentiation in tetrakas (Bernieridae) endemic to Madagascar: A multi-isotope approach
IntroductionTropical rainforest species interact with each other and their environment over a wide range of spatiotemporal scales. However, our understanding of resource partitioning and the mechanisms of avian species coexistence is largely restricted to subjective visual observations or acoustic monitoring. Therefore, the relative magnitudes of interspecific and intraspecific differences in resource use have remained difficult to quantify, particularly regarding different diets and habitat use. The eastern rainforest belt of Madagascar is inhabited by several species of insectivorous tetrakas belonging to an endemic bird family of Madagascar (Bernieridae). These species occupy similar habitats in the forest understory and are morphologically similar but because of likely differences (e.g., in foraging behaviors) we expect their foraging niches to be segregated allowing coexistence.MethodsWe examined the niche differentiation of four of these species: the Grey-crowned Tetraka (Xanthomixis cinereiceps), Long-billed Tetraka (Bernieria madagascariensis), Spectacled Tetraka (Xanthomixis zosterops), and White-throated Oxylabes (Oxylabes madagascariensis) in the Maromizaha rainforest in eastern Madagascar combining morphometry with stable carbon, nitrogen, and sulfur isotope ratios (δ13C, δ15N, and δ34S) from feathers.ResultsWe show considerable variation in isotopic niche positions, niche breadth and interspecific niche overlap. In two species, the Long-billed Tetraka and Spectacled Tetraka, we found an indication of sex-specific niche space, with males exhibiting a larger isotopic niche-area relative to females. Morphological traits of five species (including the Wedge-tailed Tetraka, Hartertula flavoviridis) coupled with stable isotope data provided explanations of patterns of niche overlap and isotopic position.DiscussionThe observed isotopic niche differences may be explained by differences in resource acquisition strategies that might be associated with specific morphological traits and spatial distribution. This may play an important role in niche differentiation among coexisting and phylogenetically closely related species
Bird handling techniques and data acquisition in the tropics and subtropics
Der Fang von Vögeln zu wissenschaftlichen Zwecken in den Tropen und Subtropen stellt eine Herausforderung für Ornithologen dar. Probleme aufgrund rechtlicher sowie sozioökonomischer und soziokultureller Rahmenbedingungen lassen sich oft durch eine intensive Vorbereitung und Kooperationen mit lokalen Partnern vermeiden oder reduzieren. Beim eigentlichen Fang sind logistische Herausforderungen wie die Materialbeschaffung vor Ort, aber auch die Ökologie einiger überwiegend tropischer Vogelgruppen zu berücksichtigen. Hier wie auch bei der Probennahme und -lagerung beeinflussen die herrschenden Umweltbedingungen die Arbeit, insbesondere extreme Witterung. Problemlösungenlassen sich jedoch teilweise nur schwer verallgemeinern. Wir unterstreichen die Bedeutung lokaler und regionaler Besonderheiten anhand zahlreicher Beispiele aufgrund eigener Erfahrungen.Capturing birds for scientific purposes in tropical and subtropical areas is particularly challenging. Problems due to general judicial, socio-economic and socio-cultural conditions can often be avoided or reduced by an intensive prearrangement and cooperation with local partners. When actually capturing birds, logistical challenges, differences in predation and the ecology of specific tropical bird groups need to be considered. In this respect and also for sampling and sample storage, environmental conditions, especially extreme weather conditions, are factors to be considered. Troubleshooting and resolving issues related to ornithology in the tropical biomes is not always straightforward. Here we emphasize the importance of local and regional peculiarities by numerous examples based on our own experiences
Widespread vulnerability of Malagasy predators to the toxins of an introduced toad
Invasive species are a key factor contributing to the global decline of biodiversity, and understanding the underlying mechanisms is crucial to mitigate detrimental effects [1]. One such mechanism is the introduction of invasive species with defensive strategies, such as novel toxins, that can disrupt native predator communities [2]. Disruption of such communities can produce trophic cascades, impacting a diverse array of taxa [2]. Madagascar, a globally significant biodiversity hotspot, has recently experienced the introduction of a toxic bufonid amphibian, the Asian common toad (Duttaphrynus melanostictus) [3]. Since its invasion, the toad population has expanded rapidly, making control efforts problematic and eradication extremely difficult [4]. Previous cases of bufonid introductions, such as the ongoing spread of the cane toad (Rhinella marina) in Australia, have resulted in the decimation of many indigenous species [2], prompting fears that Madagascar may be similarly impacted [4]. Here we show that these fears are warranted: we demonstrate that many Malagasy vertebrates are likely to be susceptible to the toxins of this invasive toad
The Genomic Footprints of the Fall and Recovery of the Crested Ibis
Human-induced environmental change and habitat fragmentation pose major threats to biodiversity and require active conservation efforts to mitigate their consequences. Genetic rescue through translocation and the introduction of variation into imperiled populations has been argued as a powerful means to preserve, or even increase, the genetic diversity and evolutionary potential of endangered species [1-4]. However, factors such as outbreeding depression [5, 6] and a reduction in available genetic diversity render the success of such approaches uncertain. An improved evaluation of the consequence of genetic restoration requires knowledge of temporal changes to genetic diversity before and after the advent of management programs. To provide such information, a growing number of studies have included small numbers of genomic loci extracted from historic and even ancient specimens [7, 8]. We extend this approach to its natural conclusion, by characterizing the complete genomic sequences of modern and historic population samples of the crested ibis (Nipponia nippon), an endangered bird that is perhaps the most successful example of how conservation effort has brought a species back from the brink of extinction. Though its once tiny population has today recovered to >2,000 individuals [9], this process was accompanied by almost half of ancestral loss of genetic variation and high deleterious mutation load. We furthermore show how genetic drift coupled to inbreeding following the population bottleneck has largely purged the ancient polymorphisms from the current population. In conclusion, we demonstrate the unique promise of exploiting genomic information held within museum samples for conservation and ecological research.© 2018 The Author(s). Published by Elsevier Ltd. This is an open access article available to all published under a Creative Commons Attribution – NonCommercial – NoDerivs (CC BY-NC-ND 4.0). The attached file is the published pdf
The role of natural science collections in the biomonitoring of environmental contaminants in apex predators in support of the EU's zero pollution ambition
The chemical industry is the leading sector in the EU in terms of added value. However, contaminants pose a major threat and significant costs to the environment and human health. While EU legislation and international conventions aim to reduce this threat, regulators struggle to assess and manage chemical risks, given the vast number of substances involved and the lack of data on exposure and hazards. The European Green Deal sets a 'zero pollution ambition for a toxic free environment' by 2050 and the EU Chemicals Strategy calls for increased monitoring of chemicals in the environment. Monitoring of contaminants in biota can, inter alia: provide regulators with early warning of bioaccumulation problems with chemicals of emerging concern; trigger risk assessment of persistent, bioaccumulative and toxic substances; enable risk assessment of chemical mixtures in biota; enable risk assessment of mixtures; and enable assessment of the effectiveness of risk management measures and of chemicals regulations overall. A number of these purposes are to be addressed under the recently launched European Partnership for Risk Assessment of Chemicals (PARC). Apex predators are of particular value to biomonitoring. Securing sufficient data at European scale implies large-scale, long-term monitoring and a steady supply of large numbers of fresh apex predator tissue samples from across Europe. Natural science collections are very well-placed to supply these. Pan-European monitoring requires effective coordination among field organisations, collections and analytical laboratories for the flow of required specimens, processing and storage of specimens and tissue samples, contaminant analyses delivering pan-European data sets, and provision of specimen and population contextual data. Collections are well-placed to coordinate this. The COST Action European Raptor Biomonitoring Facility provides a well-developed model showing how this can work, integrating a European Raptor Biomonitoring Scheme, Specimen Bank and Sampling Programme. Simultaneously, the EU-funded LIFE APEX has demonstrated a range of regulatory applications using cutting-edge analytical techniques. PARC plans to make best use of such sampling and biomonitoring programmes. Collections are poised to play a critical role in supporting PARC objectives and thereby contribute to delivery of the EU's zero-pollution ambition.Non peer reviewe
Sammlungsrichtlinien am Beispiel naturkundlicher Sammlungen
Realität für viele naturkundliche Sammlungen an Museen und Universitäten sind leider oft unzuläng-liche Räumlichkeiten, unsachgemäße Aufbewahrung, geringe Erschließung und fehlendes oder schlecht ausgebildetes Personal. Die Ursachen dafür sind vielfältig und meistens bedingt durch mangelnde Gelder der öffentlichen Hand. Auf verschiedensten Ebenen wird deshalb versucht, in Projekten, Initiativen und Arbeitsgruppen Lösungswege zu entwickeln und zu beschreiten. Dabei reicht das Spektrum vom Erfahrungsaustausch auf Technikerebene über das Entwickeln von Qualitäts-standards und Richtlinien im Sammlungsmanagement bis hin zu gemeinsamen, strategischen Entscheidungen auf Direktorenebene – und vom regelmäßigen Erfahrungsaustausch innerhalb einer Institution bis hin zu europäischen und weltweiten Kooperationen. Die Welt der Naturkundemuseen versteht sich nicht als geschlossene Gesellschaft, sondern als ein für vielfältige Kooperationen offenes System. Wir geben Beispiele für laufende Projekte und Arbeitsgruppen, Sammlungsstandards und -richtlinien und bieten damit Ideen und Anknüpfungspunkte für weitere Aktivitäten
A multi-isotope and morphometric analysis to uncover ecological niche divergence in two endemic island birds from Madagascar : the Dark and Common Newtonia (Vangidae)
The common ancestry of congeneric species implies that their morphology and ecology are similar, and thus that these closely related species may experience intensified levels of competition when sympatrically distributed. Under such circumstances, selective pressure may lead to niche partitioning between and within species, with segregation achieved through variation in morphology, ecology and life history. Examining the mechanisms underlying the coexistence or segregation of congeneric species requires detailed data on aspects of their ecology such as their feeding behaviour or habitat use. Endemic island birds, such as the vangas of Madagascar, are good candidates for studying processes of niche segregation. Vangas underwent rapid speciation following the initial colonization of the island by a shared ancestor and now provide a prime example of adaptive radiation, with considerable variation in body size and shape. Four small species of Newtonia are an exception to this variation, as they show morphological overlap and partial spatial range sympatry. Here, we describe the morphology of two Newtonia species, the Common Newtonia Newtonia brunneicauda and Dark Newtonia Newtonia amphichroa, with respect to their ecology and trophic niches using a multi-isotope approach (stable isotope ratios of carbon, nitrogen and sulphur). We report evidence for adaptations involving morphological feeding traits and provide data on contrasting trophic niches between two species with a close phylogenetic relationship. We document micro-habitat niche specialization that may be due to vertical stratification within the forest. Differences in feather isotopic signatures indicate different nutrient sources and point towards microhabitat segregation that is sufficient to maintain species integrity and permit coexistence.publishe