Boerenlandvogels – WP

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  • Nederlandse natuur staat er slechter voor dan ooit

    Sinds 1990 zijn populaties wilde dieren in zowel open natuurgebieden zoals heide, als in het agrarisch landschap, gemiddeld gehalveerd. Diverse vogel-, vlinder- en reptielensoorten die vroeger algemeen voorkwamen zijn tegenwoordig zeldzaam. Deze zorgwekkende ontwikkeling blijkt uit het vandaag door het Wereld Natuur Fonds (WWF-NL) gepubliceerde Living Planet Report Nederland, getiteld ‘Natuur en Landbouw Verbonden’.

    Directeur Wereld Natuur Fonds, Kirsten Schuijt: “Ons landschap wordt monotoon en stil, zonder dat we het in de gaten lijken te hebben. Want heide bloeit nog steeds prachtig paars en weilanden zijn groen. Maar wie weet nog dat vroeger wolken vlinders op de heide te zien waren en je omringd werd door het geluid van vogels? En dat het boerenland een walhalla was voor weidevogels, bloemen en insecten? We hebben de natuur inmiddels zo diep uitgehold dat ons welzijn en onze welvaart in het geding komen. Rijke, diverse natuur is nodig voor schoon water, bestuiving van gewassen en natuurlijke plaagbestrijding.”

    Dierpopulaties in open natuurgebieden, zoals heide, zijn de afgelopen dertig jaar sterk achteruitgegaan. Unieke planten van het heidelandschap worden overwoekerd door snel groeiende grassen. Veel vlinders en andere insecten zijn het slachtoffer van het verdwijnen van hun voedselplanten. Het tekort aan insecten werkt negatief door op de insectenetende dieren, zoals vogels. Iconische soorten zoals korhoen en tapuit worden ernstig bedreigd, de duinpieper is al verdwenen.

    In agrarische gebieden zijn populaties wilde dieren gemiddeld gehalveerd. Van de boerenlandvogels behoren de veldleeuwerik, patrijs en kemphaan tot soorten die de sterkste daling laten zien. De achteruitgang onder vlinders van het boerenland is schrikbarend: de populaties zijn met gemiddeld 60 procent afgenomen. De meeste soorten, waaronder de argusvlinder en het geelsprietdikkopje, komen alleen nog voor op dijken, bermen en akkerranden.

    Bron: Nature Today, februari 2020
    https://www.naturetoday.com/nl/nl/nature-reports/message/?msg=25857

  • Iconic mayfly populations have declined by as much as 84 percent

    The emergence of Hexagenia limbata mayflies, throughout the Great Lakes and parts of the mid-Atlantic region, is nearly a religious event in angling circles. Each year in early June, these enormous mayflies blanket the landscape, emerging by the billions each night, smothering waterways, riverbanks, roadways and more with thousands of tons of trout-candy biomass. Not long ago, these historic and essential emergences were almost wiped out. By 1970, Hexagenia were gone from large swaths of the Midwest. Vast sections of the Mississippi, Illinois and Ohio rivers lacked the storied mayflies and the entire Western Lake Erie Hexagenia population was completely extirpated.

    Following the introduction of the Clean Water Act in 1972 and two decades of targeted conservation and restoration efforts, Hexagenia populations began to rebound. Hex from populations that persisted recolonized formerly Hex-rich waterways. By the 1990s, the historic, suffocating emergences of Hexagenia had returned. Unfortunately, according to a new study, Hex are once again suffering a precipitous decline. The study, recently published in the journal PNAS, analyzed radar observations of mayfly emergences to quantify long-term changes in annual biomass transport along the Upper Mississippi River and Western Lake Erie Basin. According to the study’s results, populations have declined dramatically from their recovered levels in the late 1990s and early 2000s.

    The study’s findings indicate a staggering 84% decline in Lake Erie Hexagenia abundance between 2015 and 2019. Though not as severe, sharp declines are also evident in Mississippi River populations, where results indicate a decrease of 52% from 2012 to 2019. Overall, the results “suggest a widespread and multi-year decline in the populations of mayflies in the American Midwest.”

    The authors highlighted both the baseline and amplifying affects of pesticide contamination of waterways, especially that of neonicotinoids, noting that “Neonicotinoid concentrations in Great Lake tributaries can be up to 40 times greater than the Chronic Concentration set by US Environmental Protection Agency Aquatic Life Benchmark.” Hex nymphs are doubly exposed to these pesticides—exposure to which results in greater susceptibility to hypoxia, reduced fitness, and increased predation—as they are present both in dissolved water and in stream and riverbed sediments, where Hex and other Ephemeridae nymphs burrow.

    “If these population trends continue,” the study warns, “persistent environmental changes could threaten to once more extirpate Hexagenia mayflies from North America’s largest waterways, making this ephemeral spectacle—and its vital ecological functions—a thing of the past.”

    Source: Hatch, Jan 23rd 2020
    https://www.hatchmag.com/articles/iconic-mayfly-populations-have-declined-much-84-percent/7714977

  • Het is de EU de afgelopen 10 jaar niet gelukt risico’s van bestrijdingsmiddelen te beperken

    Pesticiden kunnen schadelijk zijn voor mens en milieu, maar het is de Europese Unie de afgelopen tien jaar nauwelijks gelukt de risico’s terug te dringen. Ook schiet de handhaving ernstig tekort. Boerenbedrijven in overtreding worden nauwelijks of niet beboet. Dat concludeert de Europese Rekenkamer in een rapport. Het onderzoek van de Rekenkamer vond plaats in Nederland, Frankrijk en Litouwen.

    Boeren mogen chemische bestrijdingsmiddelen alleen gebruiken als er geen andere (effectieve) manier is om gewassen te beschermen tegen insecten, schimmels of andere voor de landbouw schadelijke organismen. Mede omdat er onduidelijkheid is over metingen en betrouwbare gegevens ontbreken, schiet de handhaving echter tekort, aldus de controleurs. “Bovendien ontbreken doelstellingen op Europees niveau. Die moeten er natuurlijk komen”, zei rekenkamerlid Samo Jereb in een toelichting.

    Van de drie lidstaten die de rekenkamer bezocht – Nederland, Frankrijk, Litouwen – heeft alleen ons land een door EU-regels verplicht boetesysteem opgetuigd. Hoewel in 2017 een op de vijf gecontroleerde landbouwers in Nederland in overtreding was, kregen zij geen boete. Zembla meldde dat in het jaar 2018 wel 137 boetes uitgedeeld die betrekking hadden op het onjuiste gebruik van gewasbeschermingsmiddelen. Uit beelden die Zembla in 2019 in handen kreeg bleek dat medewerkers van een broccolibedrijf uit West Friesland meerdere jaren onbeschermd bloot zijn gesteld aan landbouwgif. Op de beelden worden meerdere regels rond het gebruik van bestrijdingsmiddelen geschonden. Zo wordt gif gespoten bij te harde wind en komen bestrijdingsmiddelen in een sloot naast de akker terecht.
    Zembla maakte meerdere uitzendingen over de risico’s voor de mens van het gebruik van landbouwgif. Zo bleek in de uitzending ‘Parkinson op het platteland’ dat landbouwbestrijdingsmiddelen die in Nederland worden gebruikt, de ziekte van Parkinson kunnen veroorzaken. In de uitzending ‘Bollengif in babyluier’ blijkt dat omwonenden van bollenvelden langer en aan hogere concentraties landbouwgif worden blootgesteld. Wat betreft controles op watervervuiling doet Nederland het volgens de Rekenkamer overigens relatief goed.

    Het Europese landbouwbeleid stimuleert boeren nauwelijks om spaarzaam met pesticiden om te springen of met alternatieven te werken, stelt de rekenkamer vast. De instantie adviseert uitbetaling van landbouwsubsidies na 2020 afhankelijk te maken van naleving van de regels. De Europese Commissie moet dan wel beter nagaan of lidstaten landbouwbedrijven wel controleren.

    In de EU wordt jaarlijks meer dan 350.000 ton pesticiden verkocht. Die brengen risico’s met zich mee voor het grond- en oppervlaktewater, de bodem, de biodiversiteit, ecosystemen en de menselijke gezondheid, onder meer door restanten in levensmiddelen. Er zijn inmiddels 487 werkzame stoffen met een laag risico goedgekeurd voor gebruik, maar slechts zestien daarvan zijn beschikbaar. “Onvoldoende”, aldus de rekenkamer, die nog eens in herinnering brengt dat biologische methoden de voorkeur verdienen.

    De Europese Commissie stelt overigens dat de risico’s van pesticiden met een vijfde zijn afgenomen, maar die claim is volgens de rekenkamer niet hard gemaakt.

    Bron: Zembla, 05-02-20
    https://www.bnnvara.nl/zembla/artikelen/rekenkamer-risicos-bestrijdingsmiddelen-nauwelijks-verminderd-in-eu

  • Germany’s breeding bird population in significant decline

    The breeding bird population in Germany declined by around 14 million or eight percent over the period between 1992 and 2016, the Federal Agency for Nature Conservation (BfN) said on Wednesday. The “significant decline” in the number of native birds in meadows, pastures and fields has been continuing, according to an evaluation of thousands of data sets by the agency. “In the open agricultural landscapes, the population of breeding pairs has declined by about two million over a quarter of a century,” BfN President Beate Jessel said. With no changes to the negative trend in sight, the results underline the “urgency of reforms in agricultural policy,” Jessel stressed.

    Source: China.org.cn, 6 Feb 2020
    http://www.china.org.cn/world/Off_the_Wire/2020-02/06/content_75676522.htm

  • Bayer attempts to discredit peer-reviewed study showing its products caused a Japan fishery to collapse

    The May 2019 newsletter of the Saitama Ecosystem Conservation Society describes how, before the introduction of neonicotinoids in the 1990s, numberless brilliant red akiakane or autumn darter dragonflies could be seen around rice fields in the fall. Experiments by Japanese dragonfly expert Tetsuyuki Ueda of Ishikawa Prefectural University showed how the pesticides reduced the number of surviving dragonfly nymphs to a small fraction, and that the chemicals persist for years in the soil of rice paddy fields.

    A team of Japanese scientists led by Dr Masumi Yamamuro published a study in the prestigious peer-reviewed journal Science in November 2019 showing how the important fishery there collapsed after the introduction of Bayer’s pesticides, and has not recovered. Nearly 300 tons of smelt was caught annually in the late 1980s, but since 1993 – when neonicotinoids were introduced in the lake watershed – the smelt catch collapsed to zero and has stayed there.

    Since the study was published, Bayer has completely dismissed its findings, as reported by Douglas Main writing for National Geographic. Carlota Gomez de la Hoz, Bayer’s head of issues communications, repeated this dismissal in a statement sent to The Ecologist by email. “We would like to emphasize that the strong conclusions made in the publication are clearly not supported, as demonstrated by the observed increase in fish and eel populations during years with higher neonicotinoid sales (and assumed use).”

    Gomez de la Hoz continued: “There is a consensus in the scientific community that understanding changes and causation in these environments requires considerably more intensive investigation than this publication offers. Neonicotinoid products…are safe when used according to instructions, and nothing in any study, including this one, has changed that.”

    However, Yamamuro, who has a PhD from the University of Tokyo, explained by email that the strict peer review process for Science took seven months, with the journal sending the study to two anonymous reviewers, whose criticisms had to be answered before the journal would publish.

    The repeated claim by Bayer that the methods and conclusions of the Lake Shinji study are wrong may therefore be considered as part of a continuing disinformation campaign against scientists that criticise the company, with the sole aim of maximizing profits for shareholders. The disinformation technique employed against Yamamuro is similar to campaigns by climate change denialists, where single anomalous events such as a cold period in winter are cherry-picked to falsely state that a long-term global heating trend does not exist.

    Bayer’s statement that in some years fish populations increased does not change the fact confirmed by the peer-review process that overall, the smelt fishery collapsed since neonicotinoids were introduced and has not recovered.

    Source: Phil Carter in The Eologist, 30 January 2020
    https://theecologist.org/2020/jan/30/bayer-and-neonicotinoids-japan

  • Rosemary A. Mason: The sixth mass extinction and chemicals in the environment: our environmental deficit is now beyond nature’s ability to regenerate

    Two papers about the future of the planet appeared within a month of each other (June/July 2015): “Accelerated modern human-induced species losses: Entering the sixth mass extinction” was the first. The 6 authors calculated the average rate of vertebrate losses over the last century and compared it with the background rate of losses. They estimated it to be up to 114 times the background rate and asserted that this rate of losses of biodiversity indicated that a sixth mass extinction is already under way. “Safeguarding human health in the Anthropocene epoch: Report of the Rockefeller Foundation–Lancet Commission on planetary health” was the second paper. The Rockefeller Foundation funded the initial research on genetically modified organisms in the early 1940s and founded the science of molecular biology, a highly reductionist programme aimed at “understanding” life.The Rockefeller Foundation’s early involvement in eugenics research and its subsequent support for depopulation are unlikely to be consummated before the sixth mass extinction.

    Source: Dr. Rosemary Mason. Journal of Biological Physics and Chemistry 15 (2015) 160–176

  • Loss of arthropod species diversity across German forests and grasslands

    Recent studies have shown that arthropods—insects, arachnids and other small, hard-bodied animals—are in trouble, from massive declines in the biomass (total weight) of flying insects to regional extinctions in a number of insect groups, such as butterflies. A new large-scale study across a number of habitats in Germany has found that the problem may be more extensive than previous research suggests.

    Between 2008 and 2017, an international team of researchers sampled arthropods from 150 grassland and 140 forest sites in three regions of Germany. The final dataset recorded the occurrence of more than one million individual insects and spiders representing 2,675 species, which the team analyzed to see how populations changed over time.

    Overall, they found a loss of species diversity across both habitat types. In grasslands, there were significant declines in arthropods’ biomass, number of individuals, and number of species (67 percent, 78 percent, and 34 percent, respectively) over the ten studied years. These losses were reported across the food web: in decomposers such as dung beetles, herbivores such as grasshoppers, and predators such as spiders. Rare arthropods were most impacted, which “has led to the local extinction of some species,” said lead author Sebastian Seibold, of the Technical University of Munich. Research sites surrounded by agricultural landscapes showed even more significant declines, though the investigators were not able to point to the exact mechanisms—such as pesticide use or habitat alteration—that might be the cause.

    In forest ecosystems, the team reported a decline in the mass and number of species (41 percent and 36 percent, respectively), but not in the total number of individual arthropods. Some species, including potential pests and invasive herbivore species, increased in wooded areas that had been working timber stands and were being returned to broadleaf forests.

    Seibold believes that piecemeal work to stave off arthropod declines, such as taking measures on one farmer’s field or a single protected area at a time, would be relatively ineffective. “There is something [happening] on a pretty large spatial scale,” he said. “What we need is a more spatially coordinated approach.”

    Source: Natural History, February, 2020
    http://www.naturalhistorymag.com/samplings/313746/bug-loss

  • Capercaillie broods in pristine boreal forest in northwestern Russia: the importance of insects and cover in habitat selection

    Capercaillie (Tetrao urogallus L., 1758), the largest and most size-dimorphic species of grouse, is decreasing in number throughout its man-modified range in the boreal forests of the Palaearctic. Poor reproduction owing to direct and indirect effects of commercial forestry is considered a main cause of the decline. We studied brood habitats in a pristine forest in northwestern Russia to identify key elements in habitat selection in the natural environment of this species. We monitored the movement of 10 radio-marked broods during their first 7 weeks of life, and compared the abundance of insects and cover at their locations (N = 120) with nearby random control sites. The broods preferentially used moist spruce forest and the insect-rich herb spruce forest, but were most often located in the more abundant vaccinium spruce forest, which was richest in bilberry (Vaccinium myrtillus L.) and associated lepidopteran larvae. Brood locations were consistently richer in insects than random controls in 3 of the 4 habitat types studied. The most pronounced difference was in the density of lepidopteran larvae, a food source known to form an important part of the diet of young capercaille chicks. Broods continued to select insect-rich sites throughout the 7 week age period; in the preferred moist spruce forest, larval abundance increased at brood locations, while it remained constant at control sites. Compared to the distribution of insects, cover did not appear to be as an important determinant of brood habitat selection, possibly because the structural characteristics were rather similar among the most widely used habitat types. Shrub cover tended to be higher at brood locations than at controls, whereas vertical cover along the ground was not different. This relationship to cover factors may reflect an adaptation to avoid predation by goshawk (Accipiter gentilis (L., 1758)), the most important predator of grouse in this pristine boreal forest.

    Source:
    Per Wegge, Thomas Olstad, Håkon Gregersen, Olav Hjeljord, and Andrey V. Sivkov. Can. J. Zool. 83: 1547–1555 (2005)

  • Dramatischer Rückgang der Auerhuhnpopulation im Schwarzwald

    Das Auerhuhn (Tetrao urogallus) gilt als Indikator artenreicher, lichter, von Nadelbäumen dominierter Wälder und besiedelt weltweit noch ein großes Areal. In West- und Mitteleuropa sind allerdings viele Verbreitungsgebiete isoliert und meist auf (Mittel-) Gebirgszüge begrenzt, viele Populationen sind bereits verschwunden oder stark zurückgegangen. Im Schwarzwald, Südwest-Deutschland, wurde die Auerhuhn-Population erstmals 1971 mittels flächendeckender Balzplatzzählungen geschätzt. Seit 1983 wurden diese Zählungen jährlich durchgeführt und dokumentiert.

    Zudem wurden seit 1988 im 5-Jahres Turnus alle Auerhuhn-Nachweise zusammengetragen um das Verbreitungsgebiet der Art zu bestimmen. Über den gesamten Erfassungszeitraum ist ein dramatisch negativer Populationstrend zu verzeichnen: Die Zahl balzender Hähne sank von 570 Hähnen im Jahr 1971 auf nur noch 167 Hähne im Frühjahr 2018. Die seit 1993 räumlich erfassten Daten zeigen, dass der stärkste Rückgang im Baarschwarzwald (von 48 Hähnen 1993 auf 8 Hähne 2018) und im Südschwarzwald (von 160 Hähnen 1993 auf 26 Hähne 2018) stattfand. Die Teilpopulation im Mittleren Schwarzwald blieb mit 11 Hähnen relativ stabil. Im Nordschwarzwald nahm die Anzahl der Hähne nach 1993 zunächst zu (von 130 1993 auf 197 2008), um dann wieder abzunehmen (122 Hähne 2018).

    Auch das Verbreitungsgebiet des Auerhuhns im Schwarzwald wurde deutlich kleiner: es schrumpfte von 606 km2 im Zeitraum zwischen 1989 und 1993 auf 344 km2 im Zeitraum zwischen 2014 und 2018. Dieser Verbreitungsrückgang erfolgte in allen Teilgebieten, der größte Rückgang fand jedoch im Baarschwarzwald statt. Mögliche Rückgangsursachen sind eine Verschlechterung der Lebensraumbedingungen durch Verdunkelung und Vorratsanreicherung der Wälder aufgrund veränderter forstwirtschaftlichen Nutzung, eine Zunahme an Prädatoren, der Klimawandel und eine stetige Zunahme anthropogener Störungen.

    Quelle:
    Joy Coppes, Judith Ehrlacher, Gerrit Müller, Klaus Roth, Karl-Eugen Schroth, Marc Förschler, Veronika Braunisch und Rudi Suchant. Vogelwarte 57, 2019: 115 – 122

  • Systemic pesticide concerns extend beyond the bees

    In the summer of 2010, Henk Tennekes from Experimental Toxicology Services Nederland at Zutphen warned that the accumulation of neonicotinoids in the environment would not only decimate useful insects but also have a knock-on effect on other species, including birds (Curr. Biol. (2011) 21, R137–R139). At the time, Tennekes did not find much support for his views and went on to publish his warnings as a book — The Systemic Insecticides: A Disaster in the Making. Recent papers from other researchers are now supporting his concerns, as they show that the damage arising from systemic pesticides isn’t limited to pollinators and that many other species, from earthworms to birds, are also affected.

    A recent study has combined the highly detailed records of bird populations on the one hand and surface water contamination with pesticides on the other to demonstrate that the rate of decline of several insectivorous birds in plots all across the Netherlands correlates significantly with the contamination of surface water with the neonicotinoid imidacloprid in the same area (Nature (2014) 511, 341–343). The species showing statistically significant correlation include: Eurasian skylark (Alauda arvensis), barn swallow (Hirundo rustica), yellow wagtail (Motacilla flava), common starling (Sturnus vulgaris), common whitethroat (Sylvia communis), and mistle thrush (Turdus viscivorus).

    Source: Michael Gross in Current Biology, Volume 24, Issue 16, 18 August 2014, Pages R717-R720
    https://www.sciencedirect.com/science/article/pii/S0960982214009683