Boerenlandvogels – WP

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  • Pestizide erhöhen Risiko für Tropenkrankheit Schistosomiasis

    Schistosomiasis ist eine schwere Infektionskrankheit, die durch parasitische Würmer hervorgerufen wird. Im Lebenszyklus des Parasiten spielen Süßwasserschnecken als Zwischenwirte eine zentrale Rolle. In ihrer aktuellen im Fachmagazin Scientific Reports veröffentlichten Studie konnten Forscher des UFZ in Kooperation mit Wissenschaftlern des International Centre of Insect Physiology and Ecology (icipe) in Kenia zeigen, dass Schneckenpopulationen in pestizidbelasteten Gewässern deutlich größer waren als in unbelasteten Gewässern. Das Risiko für eine Ansteckung mit Schistosomiasis könne durch in der Landwirtschaft eingesetzte Pestizide regelrecht angeheizt werden, warnen die Forscher.

    Quelle:
    Jeremias M. Becker, Akbar A. Ganatra, Faith Kandie, Lina Mühlbauer, Jörg Ahlheim, Werner Brack, Baldwyn Torto, Eric L. Agola, Francis McOdimba, Henner Hollert, Ulrike Fillinger, Matthias Liess (2020): Pesticide pollution in freshwater increases risk of human infection with schistosomiasis, Scientific Reports, https://doi.org/10.1038/s41598-020-60654-7

  • Imidacloprid pollution in freshwater paves the way for schistosomiasis transmission

    Schistosomiasis is a severe neglected tropical disease caused by trematodes and transmitted by freshwater snails. Snails are known to be highly tolerant to agricultural pesticides. However, little attention has been paid to the ecological consequences of pesticide pollution in areas endemic for schistosomiasis, where people live in close contact with non-sanitized freshwaters.

    In complementary laboratory and field studies on Kenyan inland areas along Lake Victoria, we show that pesticide pollution is a major driver in increasing the occurrence of host snails and thus the risk of schistosomiasis transmission. In the laboratory, snails showed higher insecticide tolerance to commonly found pesticides than associated invertebrates, in particular to the neonicotinoid Imidacloprid and the organophosphate Diazinon. In the field, we demonstrated at 48 sites that snails were present exclusively in habitats characterized by pesticide pollution and eutrophication. Our analysis revealed that insensitive snails dominated over their less tolerant competitors.

    The study shows for the first time that in the field, pesticide concentrations considered “safe” in environmental risk assessment have indirect effects on human health. Thus we conclude there is a need for rethinking the environmental risk of low pesticide concentrations and of integrating agricultural mitigation measures in the control of schistosomiasis.

    Source:
    Becker, J.M., Ganatra, A.A., Kandie, F. et al. Sci Rep 10, 3650 (2020). https://doi.org/10.1038/s41598-020-60654-7

  • Common birds of Western Ghats see steep decline in past 25 years

    In what is the first comprehensive assessment of the distribution, abundance and conservation status of bird species in India, a study, titled the State of India’s Birds 2020, has found that the birds in the Western Ghats have seen a steep decline in number in the last 25 years.

    The study was conducted by collaboration between 10 research and conservation organisations within the country, spanning governmental and non-governmental institutions, including World Wide Fund for Nature India (WWF-India) and Ashoka Trust for Research in Ecology and the Environment (ATREE). They collected data uploaded by over 15,000 birders. These birdwatchers, spread across two lakh locations, uploaded data on the eBIrd India platform in Laboratory Ornithology at Cornell University.

    The analysis showed that the 12 species endemic to the Western Ghats – for whom long-term data could be found – are almost 75% lower in abundance today than the year 2000. This steep decline was worryingly found even in common species such as Crimson-backed Sunbird (Leptocoma minima) and Yellow-browed Bulbul (Acritillas indica).

    The 12 species, taken into account for long-term analysis, were Malabar Grey Hornbill, Malabar Barbet, Malabar Parakeet, Malabar Woodshrike, White-bellied Treepie, Nilgiri Flowerpecker, Crimson-backed Sunbird, Flame-throated Bulbul, White-bellied Blue Flycatcher, Dark-fronted Babbler, Yellow-browed Bulbul and the Square-tailed Bulbul. In the last five years, however, there appears to be a stabilising trend in these species, said Ashwin Viswanathan, a researcher at the National Conservation Foundation who also worked on the report.

    Half of these 12 reported a strong decline, that is, a long-term decline of over 50% and annual decline of more than 2.7%. The other half reported a moderate decline – an overall decline of more than 25%, and annual decline of more than 1.1%.
    The long-term trend was measured by observing trends over 25 plus years, while the current annual trend was recorded over the past five years. Apart from these two, a third index of Distribution Range Size (i.e. how widespread the bird’s presence in India is, measured in sq km), along with the International Union of Conservation of Nature (IUCN) Red List, were used to classify 867 species of birds accounted for in the report, based on conservation concerns.

    The IUCN Red List was established in 1964 and is considered the world’s most comprehensive inventory of conservation status of biological species, which shows the risk of extinction.

    Source: News Minute, 17 Feb 2020
    https://www.thenewsminute.com/article/common-birds-endemic-western-ghats-see-steep-decline-past-25-years-118342

  • The endangered Taita birds of Kenya

    Across the expansive Taita Plains in Southern Eastern Kenya, rises a majestic densely forested hilly outcrops straddling the skyline near the historic town of Voi. These hilly outcrops, famously known as the Taita Hills occupy an area of about 250 square kilometers. In addition to being an important biodiversity hotspot and water tower, the densely forested hills form an important ecosystem consisting of a number of forests, home to various animals and rare bird species.

    Some of these endangered birds include the Endangered Taita White (Zosterops silvanus), Taita Thrush (Turdus helleri), and the Critically Endangered Taita Apalis (Apalis fuscigularis), one of the rarest birds in the world with only 150 birds remaining in the wild.

    Contributing to the decline of these endangered bird species is severe habitat loss, as a result of human activities. Increasing human settlement has adversely affected the forests and bushes where the birds live. “Over the years, Taita Hills’s forested areas have fragmented with about 98% of the original forest being destroyed. This severe habitat loss has put enormous pressure on these endangered birds,” notes Paul Kariuki, Head of Conservation at BirdLife Africa.

    Source: BirdLife International, 25 Feb 2020
    http://www.birdlife.org/africa/news/species-brink-saving-endangered-taita-birds-kenya

  • Tientallen unieke Limburgse diersoorten zijn ernstig bedreigd

    In Limburg worden veel planten- en diersoorten die uniek zijn voor deze regio ernstig bedreigd. Er is een lijst van 28 bedreigde diersoorten die binnen Nederland alleen – of in belangrijke mate – in Limburg voorkomen.

    Bekend zijn het vliegend hert (Lucanus cervus), de korenwolf (Cricetus cricetus), de eikelmuis (Eliomys quercinus) en de vuursalamander (Salamandra salamandra). Maar het gaat ook slecht met de knoflookpad (Pelobates fuscus), boomkikker (Hyla arborea) , vroedmeesterpad (Alytes obstetricans), geelbuikvuurpad (Bombina variegata), kamsalamander (Triturus cristatus), zandhagedis (Lacerta agilis), gladde slang (Coronella austriaca), muurhagedis (Podarcis muralis), otter (Lutra lutra), hazelmuis (Muscardinus avellanarius), wilde kat (Felis silvestris), ingekorven vleermuis (Myotis emarginatus), meervleermuis (Myotis dasycneme), Bechsteins vleermuis (Myotis bechsteinii), vale vleermuis (Myotis myotis), grauwe klauwier (Lanius collurio), rode wouw (Milvus milvus), boomvalk (Falco subbuteo), wespendief (Pernis apivorus) , het donker pimpernelblauwtje (Phengaris nausithous) en de patrijs (Perdix perdix). Ook diverse plantensoorten hebben het moeilijk. De veenmossen in De Peel worden sterk bedreigd.

    Bron: De Limburger, 05-05-19
    https://www.limburger.nl/cnt/dmf20190507_00104545/tientallen-limburgse-diersoorten-ernstig-bedreigd

  • Bats are directly and indirectly affected by neonicotinoid insecticides

    Based on the science available to date, there is evidence to support the claim that bats are being negatively affected by neonicotinoid insecticides in several different ways, indirectly through reduction in insect abundance and directly through impairment.

    Despite being generalists, bats are highly dependent on an abundant supply of insects in the right size class. Their foraging expenditures are such that they require high insect densities in order to provide a net energetic balance and their echolocation system limits the size range of insects available to them. Reduced prey availability will cause bats to stop foraging altogether and wait for better conditions.

    There is current evidence for reduced insect densities associated with agricultural intensification. Although this intensification predated the neonicotinoid class of insecticides, there is increasing evidence that neonicotinoids are worsening the situation and hastening insect declines. This is because of their persistence, mobility and systemic nature, their very high invertebrate toxicity as well as their indiscriminate use in prophylactic treatments.

    Most of the evidence to date for a neonicotinoid-accelerated decline is for terrestrial insects (e.g. pollinators, butterflies, predators and parasitoids). However the extent and level of aquatic contamination from neonicotinoid insecticides as well as the heavy use of surface water by many of our bat species suggest that a reduction in aquatic emerging insects is a key aspect of the bat vs. neonicotinoid insecticide question – indeed as has been shown to be the case with insectivorous bird species (Hallman et al. 2014).

    The impact of neonicotinoid insecticides is very much extended both in time and space compared to the aquatic impacts from older products such as organophosphorous or pyrethroid insecticides. There is evidence that entire watersheds are being contaminated at damaging levels on a year-long basis.
    In addition, the best available evidence strongly suggests that neonicotinoid insecticides are affecting bats directly. Despite the fact that these insecticides tend to be of lower toxicity than some of their predecessors (e.g. many organophosphorous insecticides previously registered), bats can be exposed to toxic levels, especially on the short and medium term (i.e. acute and summer-long exposures).

    There is a real potential for bats to be acutely affected if they forage in or on the edges of treated fields or tree crops. Levels of residues expected, whether from foliar, air blast or seed treatment uses are high enough to put bats at risk of motor impairment and death. It is somewhat counter-intuitive that risk can be as high as or higher from seed treatments than from sprays applications. This is because of the high amount of dust generated in the seeding process. Because seed treatments are currently used prophylactically on a large proportion of the total crop area for our major field crops (e.g. corn, soy, cereals, oilseeds), there will be a risk to bats on most of our agricultural crop area.

    Source:
    Mineau, P. and C. Callaghan 2018. Neonicotinoid insecticides and bats: an assessment of the direct and indirect risks. Canadian Wildlife Federation. 87 pp.

  • Unseren Fledermäusen geht die Nahrung aus

    Deutschlands Fledermäuse erwachen jetzt aus ihrem Winterschlaf. Doch die Nahrungssuche wird für Fledermäuse immer schwieriger. „Unsere Fledermäuse ernähren sich grundsätzlich von Insekten. Ab der Abenddämmerung jagen unsere 25 heimischen Fledermausarten vor allem Mücken und Nachtfalter. Um zu überleben, muss eine Fledermaus täglich bis zu einem Drittel ihres eigenen Körpergewichts fressen. Das entspricht bis zu zehn Gramm, allein in den Sommermonaten kommt so rund ein Kilogramm Insekten-Nahrung zusammen. Doch seit einiger Zeit beobachten wir einen alarmierenden Rückgang unter ihnen, dessen Umfang noch keiner genau kennt“, so Karl Kugelschafter, Sprecher der NABU-Bundesfachausschusses Fledermäuse.

    Betroffen sind nicht nur einzelne Insektenarten, sondern die Gesamtzahl. Für Fledermäuse ist dies eine fatale Aussicht, ebenso für die gesamte Nahrungskette. Fledermausforscher des NABU warnten daher auf einer Tagung im hessischen Wetzlar vor einem drohenden starken Rückgang von Mausohr, Zwergfledermaus und Co. „Fledermäuse sind auf Insekten angewiesen, genauso wie Mauersegler oder Schwalben. Sterben die Insekten, werden Blumen und Bäume nicht mehr bestäubt. Unsere gesamte Nahrungskette steht mit dem Zustand der Insektenwelt auf der Kippe“, warnte NABU-Präsident Olaf Tschimpke, der die Tagung in Wetzlar eröffnete.

    Quelle: NABU, April 2017
    https://www.nabu.de/news/2017/04/22264.html

  • Die Igel verschwinden aus Zürich

    Der Igel ist ein robustes Tier. Nicht nur seiner Stacheln wegen, die ihm Feinde vom Leib halten. Die kleinen Insektenfresser können sich durchaus auch im städtischen Siedlungsraum behaupten, solange sie Büsche, Hecken oder Reisighaufen vorfinden, in denen sie sich verstecken können, und offene Bereiche für die Futtersuche. So war der Igel denn auch in der Stadt Zürich in den 1990er Jahren noch weitverbreitet. Doch wie eine grossangelegte Studie nun zeigt, hat sein Vorkommen in Zürich drastisch abgenommen.

    Aus einem Drittel der Areale, die er vor 25 Jahren noch bewohnte, hat er sich mittlerweile zurückgezogen. «Wir sind beunruhigt über das Ergebnis», sagt die Wildtierbiologin Sandra Gloor, «auch weil wir noch keine Erklärung für den Rückzug der Igel haben.» Gloor war schon 1992 an der Igel-Studie in Zürich beteiligt. «Damals haben wir in Altstetten und Wipkingen noch viele Igel gefunden, heute hat es in den beiden Quartieren praktisch keine Igel mehr.»

    Gloor verweist auch auf eine publizierte Studie aus Deutschland, die zeigte, dass in 63 deutschen Naturschutzgebieten die Masse der Fluginsekten um 76 Prozent abgenommen hat. Fehlt dem Igel vielleicht die Nahrungsgrundlage? «Nicht, dass es einen direkten Zusammenhang zu den Igeln geben muss; aber es sind schon Entwicklungen, die man im Auge behalten sollte.»

    Quelle: NZZ, 14.12.17
    https://www.nzz.ch/zuerich/drastischer-rueckgang-die-igel-verschwinden-aus-zuerich-ld.1338624

  • UN-Artenschutzkonferenz in Indien beschließt Maßnahmen zum Schutz wandernder Tierarten

    Insektensterben und Lichtverschmutzung werden erstmals auf UN-Ebene verhandelt. Bundesumweltministerin Svenja Schulze: „Das Jahr 2020 muss zum Wendepunkt für den internationalen Arten- und Naturschutz werden. Die Vertragsstaatenkonferenz der Bonner Konvention in Indien hat hierfür den Ton angegeben: Wir brauchen weitere Fortschritte, um bedrohte Tierarten vor dem Aussterben zu schützen. Dazu gehören auch konkrete Schutzmaßnahmen vor Ort, um wandernden Tierarten bessere Lebenschancen zu geben.“

    Erstmals auf internationaler Ebene nimmt die Staatengemeinschaft die zunehmende Lichtverschmutzung und das Insektensterben stärker in den Blick. Die Bundesregierung hatte sich erfolgreich dafür eingesetzt, beide Themen auf die internationale Ebene zu heben, da diese Entwicklungen gravierende Auswirkungen auch auf wandernde Tierarten haben. Bundesumweltministerin Schulze: „Das Insektensterben ist eine internationale Herausforderung, die die Ökosysteme ins Mark trifft. Denn mit den Insekten schwinden auch die Nahrungsquellen, gerade für wandernde Tierarten wie Fledermäuse und Zugvögel. Darum ist es gut, dass die Staaten der Bonner Konvention beschlossen haben, den Pestizideinsatz in und um ausgewiesene Schutzgebiete zu senken und das Problem übermäßiger Lichtverschmutzung weltweit gemeinsam anzugehen.“

    Quelle Bundesministerium für Umwelt, Naturschutz und nukleare Sicherheit | 2020
    https://www.sonnenseite.com/de/umwelt/un-artenschutzkonferenz-in-indien-beschliet-manahmen-zum-schutz-wandernder-tierarten.html

  • Snakes ‘starving’ because of shortage of frogs to eat

    Snakes have been ”starving” to death after a mass die-off of forest frogs deprived them of their unusual meal, scientists have discovered. More than 500 frog species in central America have declined in numbers, including 90 that have gone extinct since 1998, biologists said. In 2004, a fungal pathogen outbreak caused a mass die-off. In the following years, numbers of snakes and the variety of species plummeted, found researchers from the University of Maryland and Michigan State University.

    “Comparing the after with the before, there was a huge shift in the snake community,” said Karen Lips, a professor of biology and co-author of the study. “The community became more homogeneous. The number of species declined, with many species going down in their occurrence rates, while a few species increased.
    “Body condition of many snakes was also worse right after the frog decline. Many were thinner, and it looked like they were starving.” Many snakes rely on frogs and the amphibians’ eggs as part of their diet.

    The study, published in the journal Science, compared seven years of data collected in a national park in Panama before the outbreak of the pathogen chytrid, with six years of survey data afterwards. The academics cannot say exactly how many snake species declined because sightings are rare, but they are sure the drop was caused by the loss of amphibians, not other environmental factors. The park is protected from habitat loss, development and pollution.

    The researchers said their findings would be important for conservation studies. “This work emphasises the importance of long-term studies to our understanding of the invisible, cascading effects of species extinctions,” Prof Lips said. “Everything we watched changed after the frogs declined. We have to know what we are losing, or we run the risk of undermining effective conservation.”

    Source: The Independent, 13 February 2020
    https://www.independent.co.uk/news/science/snakes-frogs-starve-panama-species-decline-extinct-a9333681.html