Boerenlandvogels – WP

Auteur: Eric

  • Binnen een week zijn 20.000 ernstig zieke of dode pimpelmezen geregistreerd in Duitsland

    De zangvogel met kobaltblauwe kruin lijkt te kampen met een besmettelijke ziekte. De Duitse natuurorganisatie Nabu heeft daarom Duitsers opgeroepen om gevallen te melden en dode vogels op te sturen voor onderzoek. Wat opvalt is dat vooralsnog weinig gevallen bekend zijn van vergelijkbare besmettingen bij andere vogelsoorten. Volgens Nabu passen de symptomen niet bij een bekende vogelziekte maar het lijkt te gaan om „een bacteriële infectie die onschadelijk is voor mensen”.

    De pimpelmees (Cyanistes caeruleus, vroeger Parus caeruleus) is een mees die in vrijwel heel Europa regelmatig voorkomt. Pimpelmezen zijn veel te zien in bossen, tuinen en struwelen.

    Pimpelmezen maken graag gebruik van vetbollen, pindanetjes en voedertafels met gevarieerde zaden. Naast het voedsel dat de mens hun aanbiedt, eten zij voornamelijk insecten en hun larven, spinnen, bladluizen, nectar en zaden.

    Bronnen:
    NRC, 17 april 2020
    https://www.nrc.nl/nieuws/2020/04/17/pimpelmezen-sterven-massaal-door-mysterieuze-ziekte-a3997077
    Wikipedia
    https://nl.wikipedia.org/wiki/Pimpelmees

  • Covid-19 outbreak was a “clear warning shot”, according to UN environment chief

    Nature is sending us a message with the coronavirus pandemic and the ongoing climate crisis, according to the UN’s environment chief, Inger Andersen. Andersen said humanity was placing too many pressures on the natural world with damaging consequences, and warned that failing to take care of the planet meant not taking care of ourselves. Leading scientists also said the Covid-19 outbreak was a “clear warning shot”, given that far more deadly diseases existed in wildlife, and that today’s civilisation was “playing with fire”. They said it was almost always human behaviour that caused diseases to spill over into humans.

    Source: The Guardian, 25 March 2020
    https://www.theguardian.com/world/2020/mar/25/coronavirus-nature-is-sending-us-a-message-says-un-environment-chief?CMP=share_btn_tw

  • The wood thrush has been disappearing from the D.C. region

    There’s something truly mysterious about the wood thrush. It’s small, tinier than its robin cousin. Its cinnamon brown color provides camouflage in the branches and shrubs that the bird calls home. And the wood thrush’s call, made to defend territory and attract mates, sounds as if it emanates from a big, complex instrument rather than this delicate creature. Although the bird’s range is large, reaching from Canada to Minnesota to Mexico, it is particularly beloved in the D.C. region.

    Like many of North America’s migrating birds, the wood thrush is in trouble. According to a 2016 study led by Smithsonian researchers, the number of breeding wood thrushes in the United States has dropped by more than 60 percent in the past five decades. “They are the poster child of declining forest songbirds,” says Calandra Stanley, a postdoctoral fellow at the Smithsonian Migratory Bird Center who’s studying how to protect the wood thrush

    Wood thrushes (Hylocichla mustelina) make their home here in the spring and summer, then migrate south to the warmer climates of Central America in the winter. They return to the D.C. region to breed in mid-April to early May, a million songs announcing their presence. Wood thrushes can produce two clutches of eggs a year with three to four eggs per clutch. Wood thrushes need vibrant, large wooded areas to survive.

    The wood thrush is an omnivore, and feeds preferentially on soil invertebrates and larvae, but will also eat fruits. In the summer, it feeds on insects continuously in order to meet daily metabolic needs. The wood thrush prefers deciduous and mixed forests for breeding. It prefers late-successional, upland mesic forests with a moderately-dense shrub layer. They nest in shrubs and eat caterpillars and larvae that live in the undergrowth, and the tree canopy helps limit hungry hawks’ field of vision.

    Sources: Washington Post, April 13, 2020
    https://www.washingtonpost.com/lifestyle/magazine/dcs-official-bird-the-wood-thrush-has-been-disappearing-from-these-parts/2020/04/10/06edbb3c-6d33-11ea-aa80-c2470c6b2034_story.html

    Wikipedia
    https://en.wikipedia.org/wiki/Wood_thrush

  • Plant diversity in European forests is declining

    In Europe’s temperate forests, less common plant species are being replaced by more widespread species. An international team of researchers led by the German Centre for Integrative Biodiversity Research (iDiv) and the Martin Luther University Halle-Wittenberg (MLU) has found that this development could be related to an increased nitrogen deposition. Their results have been published in the journal Nature Ecology & Evolution.

    The number of animal and plant species is declining globally. By contrast, there are occasionally opposing trends in individual local ecosystems, where there may even be evidence of an increase in species richness (number of species). How can this apparent contradiction be explained, and what are the reasons for it?

    It was precisely these questions that an international team of scientists wanted to explore. Using data from a total of 68 different locations in temperate forests in Europe — including forest sites in Thuringia, Saxony-Anhalt and Bavaria — they investigated how the diversity of herb-layer plant species has changed over the past decades. For this, the researchers had to assess stocks of 1,162 different plant species. This set of data was compiled by a network of forest ecologists, called forestREplot. “This network has the advantage that the experts on the actual locations can be asked if something is unclear, and, in this way, it differs from many other large databases,” said lead author Ingmar Staude, a doctoral student at iDiv and the MLU.

    The analysis of these data was made possible by the sDiv synthesis centre of iDiv. The scientists found that plant species with a small geographical range, which can often be found in only a few forests, tend to have an increased risk of extinction within the respective forests. “This is not so much due to the smaller population size of such plants, but rather to their ecological niche,” explains Ingmar Staude. Small-ranged species are often those adapted to relatively few nutrients in the soil.

    The scientists were able to show that chronic and excessive nitrogen deposition in many parts of Europe is related to the increased risk of extinction of such species. In contrast, plant species that prefer nutrient-rich soils, such as nettle and blackberry benefit. These plants grow faster under higher nutrient supply and have now a sudden competitive advantage.

    While small-ranged species have disappeared, widespread, nitrogen-loving, and occasionally exotic species are on the rise. The average biodiversity of individual forests has therefore not actually decreased. However, the biodiversity of the biome has decreased as small-ranged species were commonly lost. Based on their research, the researchers estimated a 4% decrease over the last decades. However, they point out that many of the sites investigated are in protected areas, and if areas used for forestry were to be examined, the decline could be even greater.

    Source: Science Daily, 13 April 2020
    https://www.sciencedaily.com/releases/2020/04/200413132810.htm

  • Insect diversity and insect abundances are higher in organic farmland

    The number of insect species and insect abundances decreased severely during the past decades over major parts of Central Europe. Previous studies documented declines of species richness, abundances, shifts in species composition, and decreasing biomass of flying insects. In this study, we present a standardized approach to quantitatively and qualitatively assess insect diversity, biomass, and the abundance of taxa, in parallel.

    We applied two methods: Malaise traps, and automated and active light trapping. Sampling was conducted from April to October 2018 in southern Germany, at four sites representing conventional and organic farming. Bulk samples obtained from Malaise traps were further analyzed using DNA metabarcoding. Larger moths (Macroheterocera) collected with light trapping were further classified according to their degree of endangerment. Our methods provide valuable quantitative and qualitative data.

    Our results indicate more biomass and higher species richness, as well as twice the number of Red List lepidopterans in organic farmland than in conventional farmland. This combination of sampling methods with subsequent DNA metabarcoding and assignments of individuals according depending on ecological characteristics and the degree of endangerment allows to evaluate the status of landscapes and represents a suitable setup for large-scale long-term insect monitoring across Central Europe, and elsewhere.

    Source:
    Axel Hausmann et al. Ecology and Evolution. 2020;00:1–12

  • Mankind’s ambivalence towards creepy crawlies

    Little is really known about the total numbers of insect species our planet holds and it is estimated that only between 10 and 20 per cent of insect and invertebrate species have been classified and named. We may well ask ourselves as to why the world’s insect population is declining with some species facing extinction? Habitat loss through urban encroachment on the countryside plus agricultural developments, pollution, climate change, and invasive species that show no respect for manmade borders together with the ever-increasing use of pesticides, insecticides, and herbicides have all contributed to the loss of insect life.

    Whilst pesticides may be the only way of controlling agricultural pests they often harm non-target species many of which are beneficial to farmers. Pesticides find their way into rivers thus killing many species of beetle and dragonfly, leading to a decline in river fish populations. As insect populations fall, so bird numbers also fall.

    Twenty-five years ago 950,000 species of insect had been described. Currently, it is estimated that there are between, approximately 3.6 and 10 million species of insect but the rate at which insect habitats have been destroyed since the Industrial Revolution suggests that many insect species have become extinct without us even knowing that they ever existed!

    On Feb 10 this year, researchers at the University of Helsinki issued a paper warning humanity about worldwide insect decline and offered sound practical solutions “to mitigate an insect apocalypse”. Such measures included the infrequent mowing of lawns and meadows, thus allowing the grass and other plants to grow and insect life to proliferate. Other suggestions included planting native trees, avoiding pesticides, leaving old trees, stumps, and dead leaves all of which attract various forms of insect life. Perhaps we all like to tidy our gardens too frequently.

    Exactly a decade ago, a most stimulating paper based on the extensive research by Dr Arthur Chung, Richard Majapun, Dr Reuben Nilus, and Frederick Kugan of the Sabah Forestry Department was published. Entitled ‘Insect diversity within the Heart of Borneo in Sabah’, this paper described in detail the ecological significance of insects in the rainforest ecosystem highlighting the importance of the role of insects in the natural world. Such an erudite account of many insect species confined to Borneo Island must provide a stimulus to all young local and budding entomologists.

    WE tend to have mixed feelings in our views of insects, which account for 75 per cent of all animal species on earth. Certainly, there are human threatening species, among which and in particular, spiders, scorpions, and centipedes provide life threatening dangers. Our own survival and our own economies depend upon some insect species and nowhere more important than in their ecological significance in the Bornean rainforest ecosystem as decomposers, pollinators, defoliators, recyclers of dead plants and animals, and animal dung.

    Source: Borneo Post Online, 29 March 2020
    https://www.theborneopost.com/2020/03/29/mankinds-ambivalence-towards-creepy-crawlies/

  • A Review of Sub-lethal Neonicotinoid Insecticides Exposure and Effects on Pollinators

    Beekeepers around the world have been reporting the ongoing weakening of honeybee health and subsequently the increasing colony losses since 1990. However, it was not until the abrupt emergence of colony collapse disorder (CCD) in the 2000s that has raised the concern of losing this important perennial pollinator. In this report, we provide a summary of the sub-lethal effects of pesticides, in particular of neonicotinoids, on pollinators’ health from papers published in peer-review journals.

    We have identified peer-review papers that are relevant to examine the effects of sub-lethal pesticide exposures on the health of honeybees (Apis mellifera), bumblebees (Bombus terrestris), and other bees from a literature search on PubMed and Google Scholar using the following combined keywords of “pollinators,” “honeybee,” “bees,” “pesticides,” or “neonicotinoids,” and from a cross-reference check of a report made available by the European Parliament in preparation to fulfill their regulatory mandate on the issue of protecting pollinators among their membership nations.

    The weight-of-evidence of this review clearly demonstrated bees’ susceptibility to insecticides, in particular to neonicotinoids, and the synergistic effects to diseases that are commonly present in bee colonies. One important aspect of assessing and managing the risks posed by neonicotinoids to bees is the chronic effects induced by exposures at the sub-lethal levels. More than 90% of literature published after 2009 directly or indirectly demonstrated the adverse health effects associated with sub-lethal exposure to neonicotinoids, including abnormal foraging activities, impaired brood development, neurological or cognitive effects, and colony collapse disorder.

    Source:
    Lu, C., Hung, Y. & Cheng, Q. A Review of Sub-lethal Neonicotinoid Insecticides Exposure and Effects on Pollinators. Curr Pollution Rep (2020). https://doi.org/10.1007/s40726-020-00142-8

  • Eastern monarch butterfly population plunges below extinction threshold

    The yearly count of monarch butterflies overwintering in Mexico, released today, shows a decrease of 53% from last year’s count and is well below the threshold at which government scientists predict the migration could collapse.

    Scientists estimate that 6 hectares—about 15 acres—is the extinction threshold for the migratory butterflies’ survival in North America. The latest count, conducted by World Wildlife Fund Mexico, found overwintering monarchs occupying just 2.83 hectares, or 7 acres.

    “Scientists were expecting the count to be down slightly, but this level of decrease is heartbreaking,” said Tierra Curry, a senior scientist at the Center for Biological Diversity. “Monarchs unite us, and more protections are clearly needed for these migratory wonders and their habitat.”

    In 2014 conservationists led by the Center for Biological Diversity and the Center for Food Safety petitioned the U.S. Fish and Wildlife Service to protect the butterfly under the Endangered Species Act. The decision on Endangered Species Act protection will be issued in December of this year under a settlement with the conservation groups. Today’s low count reinforces the need to protect the beleaguered pollinator.

    Monarch caterpillars only eat milkweed, but the plant has been devastated by increased herbicide spraying in conjunction with corn and soybean crops that have been genetically engineered to tolerate direct spraying with herbicides. In addition to glyphosate, monarchs are threatened by other herbicides and by neonicotinoid insecticides that are toxic to young caterpillars and decrease the health of adult butterflies.

    “Both the law and science require that we must protect monarchs under the Endangered Species Act before it’s too late,” said George Kimbrell, legal director for the Center for Food Safety. “Monsanto’s profits cannot come before the monarch’s future.”

    About 99% of all North American monarchs migrate each winter to oyamel fir forests on 12 mountaintops in central Mexico. Scientists from World Wildlife Fund Mexico estimate the population size by measuring the area of trees turned orange by the clustering butterflies.

    Monarch butterflies west of the Rocky Mountains overwinter on the coast of California. As recently as the mid-1990s, monarchs covered nearly 21 hectares of forest in their wintering ground. Their most recent numbers, however, were below 30,000 for the second year in a row, down from 1.2 million two decades ago.

    Source: Phys. Org, March 2020
    https://phys.org/news/2020-03-eastern-monarch-butterfly-population-plunges.html

  • De oorsprong van de Insectenapocalyps is te vinden in La Selva

    La Selva is een strook intacte Costa Ricaanse jungle die beschermd is tegen ontwikkeling, specifiek voor gebruik door wetenschappelijke onderzoekers en docenten. La Selva wordt erkend als een van de meest productieve veldstations ter wereld voor tropisch onderzoek en publicaties. Het is een ongelooflijk waardevolle bron voor wetenschappers, en hoewel beschermd, is het niet ondoordringbaar.

    La Selva is een landschiereiland omgeven door intensieve landbouw. Aan de directe rand van het park zijn er bananenplantages, ananas- en palmgewassen en andere landbouw waar ongereguleerde hoeveelheden pesticiden worden gebruikt. Nieuw onderzoek toont aan dat die pesticiden het park binnenkomen.

    “La Selva is iets meer dan 1600 hectare”, zei biologieprofessor Lee Dyer. “Het is eigenlijk maar een fragment, maar het is omgeven door landbouw en een deel van die landbouw is geïntensiveerd. Er zijn meer ananasplantages, meer palmplantages. De bananenplantages zijn veranderd van coöperaties naar grotere bedrijven, dus er zijn veel meer insecticiden, nematociden, fungiciden en herbiciden die hun weg vinden naar La Selva. Het is moeilijk voor te stellen dat die veranderingen hier geen impact zouden hebben op de insectenpopulaties. ”

    “Het is echt een uitdaging om voor elk klein organisme te pleiten, iets dat geen ijsbeer is die zijn leefgebied verliest”, zei Dyer. ‘Maar we zijn biljoenen dollars per jaar verschuldigd aan ecosysteemdiensten – bestuiving, onze gewassen groen houden, ons water schoon houden – aan de wereld van insecten. We moeten ze zelfs de eer geven voor veel van onze kunst en cultuur. De film ‘Alien’ is eigenlijk een film over een parasitoïde. ”

    Bron: Nevada Today, 19 maart 2020
    https://www.unr.edu/nevada-today/stories/insect-apocalypse

  • The Origin of the Insect Apocalypse can be found at La Selva

    La Selva is a swath of intact Costa Rican jungle protected from development specifically for use by science researchers and educators. Hints of research projects can be seen along the over 30 miles of pathways that weave through the jungle – a tree tagged with orange tape, a 3-square-foot plot of jungle marked off with string.

    La Selva is recognized as one of the most productive field stations in the world for tropical research and peer-reviewed publications. It is an incredibly valuable resource for scientists, and while protected, it is not impermeable. La Selva is a peninsula of land surrounded by intense agriculture. On the direct perimeter of the park, there are banana plantations, pineapple and palm crops and other agriculture where unregulated amounts of pesticides are being used. New research is showing that those pesticides are entering the park.

    “La Selva is just over 1600 hectares,” biology professor Lee Dyer said. “It’s really just a fragment, but it’s surrounded by agriculture and some of that agriculture has intensified. There are more pineapple plantations, more palm plantations. The banana plantations have moved from being cooperatives to being run by larger companies, so there are a lot more insecticides, nematocides, fungicides and herbicides that are making their way into La Selva. It’s hard to imagine that those changes would not have an impact on the insect populations here.”

    “It’s really challenging to advocate for any small organism, something that’s not a polar bear that’s losing its habitat,” Dyer said. “But we owe trillions of dollars a year in ecosystem services – pollination, keeping our crops green, keeping our water clean – to the world of insects. We even have to give them credit for a lot of our arts and culture. The movie ‘Alien’ is basically a movie about a parasitoid.”

    Source: Nevada Today, March 19, 2020
    https://www.unr.edu/nevada-today/stories/insect-apocalypse