Boerenlandvogels – WP

Amfibie: Algemeen

  • Save the frogs

    Save the frogs

    Frogs are one of the oldest vertebrates on this planet. They have survived four mass extinctions, but currently they face rapid decline mostly due to habitat loss, pollution, pesticide use, over harvesting for food, collection for dissection and experimentation, disease, shrinking water sources, lack of conservation awareness and so forth. This has caused the extinction of hundreds of species worldwide.

    About one-third of the total amphibian population is threatened with serious risks of extinction. According to the IUCN Red List of Threatened Species, the percentage of threatened amphibian species is above 40 percent, and that’s way higher than for mammals (25 percent) and birds (13 percent). Dissection is a major reason behind the disappearance of frogs. In Nepal, four major species, namely the tiger frog which is listed in Appendix II of CITES (Convention on International Trade in Endangered Species of Wild Fauna and Flora), Nepal cricket frog, Tarai cricket frog and skittering frog are highly exploited for dissection.

    Knowingly or unknowingly, the existence of frogs living in close proximity to humans has benefitted us in a multitude of ways. First, tadpoles (the larval stage of amphibians) help in cleaning water resources by consuming organic debris and algae enriching the oxygen content of the water. The adult frog then helps to check vector borne disease carrying insects like mosquitoes and flies. They are also a source of food for many predators like snake, hawk, jackal and wild dog, thus helping to balance the ecosystem. Farmers have always regarded frogs as their friend because they help to control pest infestation that destroys their crops. Scientists know that diminutive animals like amphibians serve as an alarm to humans by playing an exceptional role as bio-indicators. The Newar community has revered frogs from eons as their saviour in the effort to get rid of the mythical demon Ghantakarna.

    Source: Kathmandu Post, June 3, 2018
    http://kathmandupost.ekantipur.com/news/2018-06-03/save-the-frogs.html

  • Earth’s biggest amphibian disappearing

    Earth’s biggest amphibian disappearing

    The Chinese giant salamander (Andrias davidianus) is one of the more prehistoric-looking animals that is still around today. These ancient creatures – dating back 170 million years – are amphibians that can grow up to six feet long and weigh 140 pounds. They’ve been depicted in Chinese culture for thousands of years, but have now become a highly coveted delicacy amongst the country’s wealthy. As a result, they have all but disappeared from their freshwater habitats.

    In order to keep up with growing demand, these amphibians are routinely harvested from the wild in an effort to stock commercial breeding farms. China has officially banned the harvesting of wild giant salamanders, but supports widespread releases of farmed salamanders as a conservation effort. But this conservation measure may actually be harming wild populations by mixing genetic lineages and facilitating the spread of diseases.

    Recently, a research team from the Zoological Society of London (ZSL) conducted a wide survey of river sites where the salamanders are known to live. These field surveys covered 97 sites in 23 Chinese provinces through a period of four years.

    “We cannot confirm survival of wild Chinese giant salamander populations at any survey sites,” the authors say in Current Biology. “And consider the species to be extremely depleted or functionally extinct across the huge surveyed area.”

    The researchers warn that these amphibians are in “catastrophic” decline, with only a handful potentially left in the wild. The species is already categorized as critically endangered in the International Union for Conservation of Nature Red List of Threatened Species.

    Source: Earth, May 25, 2018
    https://www.earth.com/news/endangered-delicacy-disappearing-salamander/

  • Pestizide bedrohen Frosch, Unke und Molch

    Pestizide bedrohen Frosch, Unke und Molch

    Nicht nur der Autoverkehr und viel befahrene Straßen quer durch die Landschaft, sondern auch Pestizide gefährden zunehmend Frösche, Kröten, Unken und Molche. “Große Rückgänge selbst bei einstigen Allerweltsarten wie dem Grasfrosch sind ein überdeutliches Alarmzeichen”, sagte der Vorsitzende des Bundes Naturschutz in Bayern (BN), Hubert Weiger, am Mittwoch in Scheyern im Landkreis Pfaffenhofen an der Ilm. Dort starteten Aktivisten vor gut 40 Jahren ihre Rettungsaktionen, bei denen heute bayernweit rund 6000 Helfer Amphibienwege an Straßen mit Zäunen schützen und die Tiere über Straßen tragen. Ihre Arbeit könne aber nichts ausrichten gegen die Folgen einer immer intensiveren Landwirtschaft, sagte Weiger.

    Pflanzenschutzmittel dringen über die feuchte, durchlässige Haut der Tiere ein, töten sie oder schwächen ihr Immunsystem. Pestizide können zudem die Entwicklung von der Kaulquappe zum erwachsenen Tier stören. Auch das Insektensterben erschwere Kröten, Fröschen und Molchen das Überleben, denn Insekten sind eine wichtige Nahrungsquelle.

    Weiger forderte eine Veränderung der Agrarpolitik mit mehr ökologischen Anbauflächen, eine bessere Vernetzung der Lebensräume von Amphibien und weniger Pflanzenschutzmittel auf den Feldern. Glyphosat müsse verboten und die Auswirkungen neuer Pestizide auf Amphibien im Zulassungsverfahren berücksichtigt werden.

    In den Tropen seien Arten durch Pestizide ausgestorben, hieß es beim BN. In Bayern leben 19 Arten, doch ein Aussterben einzelner Arten sei auch hier nicht ausgeschlossen. “Wenn wir nicht handeln, könnte es sein, dass eines Tages das Quaken der Frösche so selten zu hören ist wie der Gesang von Braunkehlchen oder des Kiebitzes”, sagte Weiger.

    Quelle: Passauer Neue Presse, 04.04.18
    http://www.pnp.de/nachrichten/bayern/2896873_Umweltschuetzer-Pestizide-bedrohen-Frosch-Unke-und-Molch.html

  • Michael McCarthy: We’ve lost half our wildlife. Now’s the time to shout about it

    Michael McCarthy: We’ve lost half our wildlife. Now’s the time to shout about it

    Most Britons remain blithely unaware that since the Beatles broke up, we have wiped out half our wildlife. Yet we are not alone. Last week, the French woke up in a dramatic way to the fact that their own farmland birds, their skylarks and partridges and meadow pipits, were rapidly disappearing: Le Monde, the most sober of national journals, splashed the fact across the top of its front page. French bird populations in general, two reports indicated, had fallen by a third just in the past 15 years, and the next day scientists said that this was symptomatic of a future facing Europe as a whole, of “biodiversity oblivion”.

    Intensive farming is the problem. Three generations of making agriculture more industrial have given Europe cheap food on a mammoth scale, but a terrible environmental price has eventually been paid, which we are only now understanding. The heart of the matter is universal pesticide use: we benefit from farming wholly based on poison, which has exterminated more and more of the insects at the base of myriad food chains in the natural world.

    In the recent past, few have cared about insect decline, because people in general don’t care about insects, but the numbers are becoming too big to ignore. The startling disclosure last October that since the fall of the Berlin Wall in 1989, the number of flying insects on nature reserves in Germany had dropped by at least 76% – more than three-quarters – went round the world.

    Can anything be done to get us off the road to biodiversity oblivion? The perhaps surprising answer is that yes, it can. We can reorder the basis of our farming, and here we stand at a major crossroads, because that is what the present Conservative government has just promised to do. On 11 January it launched a 25-year environment plan, and followed it up on 27 February with a consultation on the future for food, farming and the environment.

    Both these documents offer to put British agriculture on a wholly new basis (partly made possible by the anticipation of Brexit): the state will continue to pay farmers, but not according to the amount of food they produce, as the EU’s common agricultural policy first ordained, or according to the amount of land they own – the situation at the moment.

    They will be paid according to the amount of environmentally friendly measures they can put in place on their land. The new philosophy is “public money for public goods”, and the environment is explicitly recognised as the principal public good.

    Senior conservationists I have spoken to are enthusiastic about these proposals. If you’re on the left, you might allege that this is mere greenwashing, a renewed attempt to detoxify the Tory brand, and of course, there will be votes in this – those vital young votes especially. But you only have to read the documents to see that this is in no way a political stunt, a crude photo-op like David Cameron with his huskies in the Arctic. These are proposals that have been deeply thought through.

    As they stand, they’re great. The principal problem will be holding the government to them. For instance, the £3.1bn in EU subsidies that British farmers currently receive, if converted into payments for agri-environment measures, would go a very long way to reversing the destruction of our wildlife; but that sum is only guaranteed until 2022. What happens after that? What’s to stop the Treasury clawing a huge chunk of it back?

    What is needed is political pressure on the government to stand by these promises. It has to come ultimately from the base, since ordinary people’s feelings are the beginnings of political will. So what must happen first is that long overdue recognition, by the public as a whole, of just how terribly our countryside has been devastated.

    We all know and love William Blake’s reference to the green and pleasant land; the time has come to acknowledge that it may still be green, but much of it, alas, is now a lifeless landscape, pleasant no longer.

    Source: Michael McCarthy in the Guardian, 26 March 2018
    https://www.theguardian.com/commentisfree/2018/mar/26/wildlife-modern-farming-insects-birds?CMP=share_btn_tw

    • Michael McCarthy is a journalist and naturalist, and author of The Moth Snowstorm: Nature and Joy

  • Das Verschwinden der Grasfrösche

    Das Verschwinden der Grasfrösche

    Der zu den Braunfröschen gehörende Grasfrosch (Rana temporaria) galt früher als „Allerweltsart“. Bis ins 20. Jahrhundert hinein landete er bevorzugt in der Fastenzeit hin- und wieder auf heimischen Tellern. Er ist fast überall in Deutschland anzutreffen. Dennoch sind auch bei dieser häufig vorkommenden Amphibienart in den letzten Jahren sehr starke Bestandsrückgänge festzustellen. In bestimmten Regionen ist er bereits ganz verschwunden, sodass er in Rheinland-Pfalz auf der Vorwarnliste der gefährdeten Arten aufgeführt ist. Die Tiere ernähren sich von Insekten, Würmern, Nacktschnecken etc. Letztendlich wird auch das Insektensterben Konsequenzen für den Grasfrosch haben, denn Insekten sind seine Hauptnahrungsquelle.

    Quelle: Blick, 09.03.18
    http://www.blick-aktuell.de/Berichte/Kroeten-und-Froesche-gehen-auf-Wanderschaft-316800.html

  • Chytridiomycosis: A Key Example of the Global Phenomenon of Wildlife Emerging Infectious Diseases

    Chytridiomycosis: A Key Example of the Global Phenomenon of Wildlife Emerging Infectious Diseases

    During the latter half of the 20th century, it was noticed that global amphibian populations had entered a state of unusually rapid decline. Hundreds of species have since become categorized as “missing” or “lost,” a growing number of which are now believed extinct. Amphibians are often regarded as environmental indicator species because of their highly permeable skin and biphasic life cycles, during which most species inhabit aquatic zones as larvae and as adults become semi or wholly terrestrial. This means their overall health is closely tied to that of the landscape. Amphibian declines in recent decades are largely attributed to increases in habitat destruction, pollution, and commercial exploitation, but enigmatic declines and mass mortality events began to be observed in seemingly healthy environments, suggesting that an additional factor with considerable negative impact was also influencing declines.

    Source: Kolby J, Daszak P. 2016. The Emerging Amphibian Fungal Disease, Chytridiomycosis: A Key Example of the Global Phenomenon of Wildlife Emerging Infectious Diseases, p 385-407. In Scheld W, Hughes J, Whitley R (ed), Emerging infections 10. ASM Press, Washington, DC. doi: 10.1128/microbiolspec.EI10-0004-2015

  • Darwin’s frog is likely to be wiped-out by amphibian fungus

    Darwin’s frog is likely to be wiped-out by amphibian fungus

    The Darwin’s frog (Rhinoderma darwinii) is the latest amphibian species to face extinction due to the global chytridiomycosis pandemic, according to an international study published today in the journal Proceedings of the Royal Society of London B. The study has found that Darwin’s frogs are infected with the fungal pathogen Batrachochytrium dendrobatidis (Bd), and despite an absence of obvious mortality researchers have noted population declines, leading them to believe that these infected populations are at a serious risk of extinction within 15 years of contracting the disease.

    Populations of this unique species, currently known as highly threatened, were previously considered to have remained relatively stable in the face of the disease that has ravaged many amphibian species worldwide, but the frogs may have been infected over a decade ago, with the impacts only recently observed.

    Led by scientists from Chile’s Universidad Andres Bello (UNAB), NGO Ranita de Darwin, and international conservation charity ZSL (Zoological Society of London), working alongside the University of Zurich, this new revelation highlights a need for urgent conservation action.

    First author, Dr. Andrés Valenzuela from ZSL’s Institute of Zoology and UNAB said: “Put simply, this study shows that once an individual animal becomes infected with Bd, it is almost certain to die. Unusually for an infectious disease even at very low rates of infection, and in the absence of the dramatic die-offs witnessed in other amphibian populations impacted by this disease, infected populations of Darwin’s frogs are destined for extinction.”

    Source: Science Daily, Sept 27, 2017
    https://www.sciencedaily.com/releases/2017/09/170927100950.htm

  • Alabama Salamander Gains Endangered Species Act Protection

    Alabama Salamander Gains Endangered Species Act Protection

    The U.S. Fish and Wildlife Service today protected Black Warrior waterdog salamanders under the Endangered Species Act, with 420 river miles of protected “critical habitat.” The rare salamanders, found only in one river basin in Alabama, are on the brink of extinction because of ongoing habitat destruction and water pollution from agricultural and industrial operations.

    “It’s fantastic that Black Warrior waterdogs (Necturus alabamensis) now have the Endangered Species Act protection that will give them the best hope for survival,” said Tierra Curry, a senior scientist at the Center for Biological Diversity. “The Endangered Species Act has prevented the extinction of 99 percent of the plants and animals under its care. This law is the best tool available for saving imperiled species like the waterdog.”

    The gilled, aquatic salamander, which can grow to nearly 10 inches in length, was first put on the candidate waiting list for federal protection in 1982. The Center petitioned for the salamander’s protection in 2004 and again in 2010. Today’s decision is the result of a Center legal victory listing 193 species as endangered and proposing protections for another four species.

    “Aquatic salamanders like the Black Warrior waterdog are indicator species that reflect the health of the environment we all share,” Curry said. “Protecting this special amphibian and its habitat will help protect water quality for both waterdogs and people.”

    Source: The Center for Biological Diversity, Jan 2, 2018
    http://www.biologicaldiversity.org/news/press_releases/2018/black-warrior-waterdog-01-02-2018.php

  • Earth has entered an era of mass extinction unparalleled since the dinosaurs died out 66 million years ago

    Earth has entered an era of mass extinction unparalleled since the dinosaurs died out 66 million years ago

    A 2015 study co-authored by Paul Ehrlich, professor emeritus of biology, and colleagues showed that Earth has entered an era of mass extinction unparalleled since the dinosaurs died out 66 million years ago. The specter of extinction hangs over about 41 percent of all amphibian species and 26 percent of all mammals, according to the International Union for Conservation of Nature (IUCN), which maintains a list of threatened and extinct species.

    The new analysis, published in Proceedings of the National Academy of Sciences, looks beyond species extinctions to provide a clear picture of dwindling populations and ranges. The researchers mapped the ranges of 27,600 species of birds, amphibians, mammals and reptiles—a sample representing nearly half of known terrestrial vertebrate species – and analyzed population losses in a sample of 177 well-studied mammal species between 1900 and 2015.

    Using range reduction as a proxy for population loss, the study finds more than 30 percent of vertebrate species are declining in population size and range. Of the 177 mammals for which the researchers had detailed data, all have lost 30 percent or more of their geographic ranges and more than 40 percent have lost more than 80 percent of their ranges. Tropical regions have had the greatest number of decreasing species while temperate regions have seen similar or higher proportions of decreasing species. Particularly hard hit have been the mammals of south and southeast Asia, where all the large-bodied species of mammals analyzed have lost more than 80 percent of their geographic ranges.

    The study’s maps suggest that as much as 50 percent of the number of animal individuals that once shared Earth have disappeared, as have billions of animal populations. This amounts to “a massive erosion of the greatest biological diversity in the history of Earth,” the authors write.

    “The massive loss of populations and species reflects our lack of empathy to all the wild species that have been our companions since our origins,” said the new study’s lead author, Gerardo Ceballos of the National Autonomous University of Mexico. “It is a prelude to the disappearance of many more species and the decline of natural systems that make civilization possible.”

    Source: Alternet, Dec 21, 2017
    https://www.alternet.org/environment/scientists-say-humans-lack-empathy-leading-global-species-annihilation

  • Die Zahl der weltweit bedrohten Tier- und Pflanzenarten hat dieses Jahr einen neuen Rekordstand erreicht

    Die Zahl der weltweit bedrohten Tier- und Pflanzenarten hat dieses Jahr einen neuen Rekordstand erreicht

    Mit rund 25’800 bedrohten Tier- und Pflanzenarten sei im zu Ende gehenden Jahr ein neuer dramatischer Höchststand erreicht worden. Ein Jahr zuvor waren es noch 24’000 bedrohte Arten. “Wir Menschen verursachen das grösste Artensterben seit Ende der Dinosaurier”, resümierte Eberhard Brandes, Vorstand des WWF Deutschland. Auch in der Schweiz gingen die Bestände einiger Arten merklich zurück. Mehr als 40 Prozent der Insektenarten in der Schweiz gälten als bedroht, darunter Bienen und Schmetterlinge, sagte WWF-Sprecherin Perrette Rey in Lausanne auf Anfrage.

    Wenn diese Entwicklung nicht gestoppt werde, habe Europa bald schon zu wenig bestäubende Insekten, die für die Landwirtschaft von entscheidender Bedeutung sind. Verantwortlich für das Massensterben von Insekten seien der Klimawandel und der intensive Einsatz von Pestiziden, sagte Rey. Auch Amphibien und insektenfressende Vögel seien vom Rückgang der Insektenarten betroffen.

    Quelle; Aargauer Zeitung, 27.12.17
    https://www.aargauerzeitung.ch/leben/forschung-technik/anzahl-bedrohter-tier-und-pflanzenarten-auf-neuem-hoechststand-132037210