Algemeen

To investigate interactions among disease, pesticides, water quality, and adjacent land cover, we collected samples of water, sediment, and frog tissue from 21 sites in 7 States in the United States (US) representing a variety of amphibian habitats. All samples were analyzed for >90 pesticides and pesticide degradates, and water and frogs were screened for the amphibian chytrid fungus Batrachochytrium dendrobatidis (Bd) using molecular methods. Pesticides and pesticide degradates were detected frequently in frog breeding habitats (water and sediment) as well as in frog tissue.

Last month, a frog died in an Atlanta botanical garden. With it went an entire species never to hop along the Earth again. Biologists at Zoo Atlanta who’d looked after the frog for the past 12 years called him “Toughie.” He was a charismatic, glossy-eyed specimen and the very last Rabbs’ fringe-limbed tree frog in the world. Joseph Mendelson, the director of research at Zoo Atlanta, had been prepared for this. When the Rabbs’ frog was discovered in Panama in 2005, some 80 percent of the population had already been lost to disease. A few were removed in hope of a revival.

Benedikt Schmidt from the University of Zurich and Silviu Petrovan from Froglife used citizen science data from the U.K. and Switzerland to assess long-term national and regional trends for one of Europe’s most abundant amphibian species, the common toad. Their findings, published in PLOS ONE, show a surprisingly severe and long-term decline in both Swiss and U.K. populations, with implications for amphibian conservation. To learn more about the study and the significance of its results, I interviewed Dr. Schmidt via email.

In Deutschland gibt es immer weniger Bienen, immer weniger Hummeln, immer weniger Schmetterlinge. Überhaupt gibt es immer weniger Insekten! Das haben Forscher aus Krefeld herausgefunden. Das ist eine Stadt im Bundesland Nordrhein-Westfalen. 25 Jahre lang haben die Forscher an bestimmten Orten Insekten gesammelt, ihre Art bestimmt und die Tiere gewogen. Das Ergebnis der Forscher: In dieser Zeit stellten sie einen Rückgang an Insekten von bis zu 80 Prozent fest. Gesammelt haben die Forscher vor allem in Nordrhein-Westfalen.

Zwei Drittel aller Amphibienarten gelten bei uns als gefährdet. Und trotz der vielfältigen Bemühungen von Naturschützern gehen die Populationen weiter zurück. Woran liegt das? Umweltwissenschaftler von der Universität Koblenz-Landau haben einen Verdacht: den Pestizideinsatz in der Landwirtschaft: Das Team um den Biologen Carsten Brühl hat sieben der gängigsten Spritzmittel an jungen Grasfröschen im Labor getestet, darunter vier Mittel gegen Pilzbefall, ein Insektizid und zwei Unkrautvernichtungsmittel.

Sie alle sind selten geworden, im Landkreis Ebersberg. Schmetterlinge in Kirchseeons Gärten sind rar geworden. Vor einigen Jahren noch zählten Tagpfauenauge, Distelfalter, Taubenschwänzchen oder der kleinen Fuchs zu den täglichen Gartenbesuchern, heute sind sie eine Besonderheit geworden. Der Sommerflieder, auf den sich in den letzten Jahren immer wieder mehrere Exemplar niederließen, lockt nach heutigen Zählungen höchsten ein Exemplar am Tag an. Noch flattern Zitronenfalter und Kohlweißlinge in der Mehrzahl statt in der Einzahl durch die Gärten, noch.

Eidechsen, Mauersegler, Schwalben, Fledermäuse und verschiedene Schmetterlingsarten sind nur ein Teil der Tiere, die im Landkreis Ebersberg immer seltener anzutreffen sind und irgendwann, wenn nichts dagegen unternommen wird, vielleicht gar nicht mehr. Inzwischen ist es etwas Besonderes, wenn Tagpfauenaugen und Distelfalter durch den Garten flattern. Der Sommerflieder, auf den sich in den letzten Jahren immer mehrere Exemplare niederließen, lockt nach heutigen Zählungen höchstens einen Schmetterling am Tag an. Auch Hummeln werden immer seltenere Gäste.

Britain’s wildlife is facing a “crisis” with more than 120 species at risk of extinction due to intensive farming, a report will warn. Hundreds of the country’s best-known animals - including types of woodpecker and butterfly - will have an uncertain future with some disappearing completely as their numbers decline rapidly, the State of Nature 2016 report will say. Sir David Attenborough, writing in a foreword for the report, is expected to label the drastic changes a “crisis”.

There has been a lot of discussion about the decline in bee populations and its dire consequences for agriculture. We have also talked about the efforts to save the monarch butterfly, whose numbers have been dropping dramatically over the years. But the rest of the insect world does not get much attention. For the most part, we think of insects as a nuisance or as potential pests. A number of studies in recent years in Germany, Great Britain, and in the United States have concluded that many insect populations worldwide are in severe decline, and this is not a good thing.

Traditional farming and gardening has long taken a straightforward approach: if an unwanted plant or animal interferes, it is to be killed. We even developed a special vocabulary to help justify our actions: the animals were “vermin” and the plants were “weeds”. And, in the case of one hen-house plunderer, we came up with the elaborate ritual that is fox hunting, complete with a special ‘language of avoidance’ that anthropologists have found in cultures around the world (the fox is a “dog”, its face is a “mask”, its tail is a “brush”, the dogs are “hounds”).