Algemeen

Study examines pesticides' impact on wood frogs

Neonicotinoids are prophylactically used globally on a variety of crops, and there is concern for the potential impacts of neonicotinoids on aquatic ecosystems. The intensive use of pesticides on crops has been identified as a contributor to population declines of amphibians, but currently little is known regarding the sublethal effects of chronic neonicotinoid exposure on amphibians.

Negative impacts of neonicotinoids in aquatic environments are a reality

Initial assessments that considered these insecticides harmless to aquatic organisms may have led to a relaxation of monitoring efforts, resulting in the worldwide contamination of many aquatic ecosystems with neonicotinoids. The decline of many populations of invertebrates, due mostly to the widespread presence of waterborne residues and the extreme chronic toxicity of neonicotinoids, is affecting the structure and function of aquatic ecosystems. Consequently, vertebrates that depend on insects and other aquatic invertebrates as their sole or main food resource are being affected.

Die Liste der bedrohten Tiere und Pflanzen im Emsland ist lang

Kiebitze (Vanellus vanellus) gehören zu den absoluten Verlierern, sagt Jutta Over vom Nabu Emsland/Grafschaft Bentheim. Sie sind im Jahr 2017 im Emsland kaum noch zu sehen und stehen wie fast die Hälfte der 140 Brutvogelarten auf der Liste der gefährdeten Arten. Over hat für unsere Redaktion zum heutigen Tag des Artenschutzes eine Liste bedrohter Tiere und Pflanzen im Emsland erstellt. Von den 140 Brutvogelarten im Emsland seien fast die Hälfte auf der Roten Liste Niedersachsens als gefährdet eingestuft, sieben davon sogar vom Erlöschen bedroht.

Infectieziektes die amfibieën op de rand van uitsterven brengen

Wereldwijd gaat het niet goed met amfibieën en infectieziektes zijn een zeer belangrijke factor die achteruitgang en uitsterven van soorten versnellen. Twee van de bekendste amfibieziektes zijn Chytridiomycose en Ranavirus. Beide komen ook in Nederland voor en zorgen lokaal voor de achteruitgang van populaties. Er zijn echter meer ziektes waar amfibieën mee te maken hebben, waaronder Amphibiocystidium-infecties. Amfibieën die zijn geïnfecteerd met soorten uit het genus Amphibiocystidium vertonen wittige tot doorzichtige blaasjes op de huid (<1 cm).

Amphibians in U.S. Declining at "Alarming and Rapid Rate"

A new study finds that frogs, toads, salamanders and other amphibians in the U.S. are dying off so quickly that they could disappear from half of their habitats in the next 20 years. For some of the more endangered species, they could lose half of their habitats in as little as six years. The nine-year study, published on May 22 in PLoS One by scientists from the U.S. Geological Survey (USGS), examined population trends for 48 species at 34 sites across the country. The researchers found that on average amphibian populations were shrinking a surprising 3.7 percent per year.

Virus lethal to amphibians is spreading across Portugal

A new strain of ranavirus is currently causing mass mortality in several species of amphibian in the Serra da Estrela, the highest mountain range in continental Portugal. This infectious agent is hypervirulent and also affects fish and reptiles, which complicates the situation, according to a study boasting the collaboration of the National Museum of Natural Sciences in Madrid.

A fungus is attacking fire salamanders and could wreak havoc if it gets to North America

Until recently, the Bunderbos was the best place in the Netherlands to find fire salamanders. With tall broadleaf trees shading small streams, the small forest was home to thousands of the 20-centimeter-long creatures, glistening black with bright yellow spots. "It's a very charismatic animal," says Annemarieke Spitzen-van der Sluijs, a conservation biologist with Reptile, Amphibian & Fish Conservation Netherlands (RAVON), a nonprofit group based in Nijmegen. "It's like a dolphin among amphibians, always smiling, with pretty eyes."

Researcher touts potential of frogs, toads in restoring native fisheries

Frogs, toads and salamanders often fall through the cracks of scientific study, but according to recently published research from Montana State University, they play a role so important they should be incorporated into strategies for conserving freshwater fisheries. In his first peer-reviewed paper as sole author, Niall Clancy, 22, said that native fish populations continue to decline around the world despite advances in management practices. Therefore, fisheries managers might want to add new approaches to the old.

Canada’s wildlife are in trouble

The Living Planet Report Canada, published today, is the most comprehensive synthesis of Canadian wildlife population trends ever conducted. It shows that on average from 1970 to 2014, half of monitored vertebrate wildlife species in the study suffered population declines. Of those, average decline is 83 per cent since 1970. The picture is also worrisome for Canada’s federally protected species. Since 2002, when the Species at Risk Act became law, federally listed at-risk wildlife populations declined by 28 per cent, the report shows.

De boomkikker zal uitsterven in de Achterhoek door insectenschaarste

Begin 1900 was de boomkikker (Hyla arborea) nog een algemeen voorkomende soort in ons landschap, maar door een steeds intensiever agrarisch gebruik is de kwaliteit van het leefgebied hard achteruit gegaan. In Nederland is deze soort nu zeldzaam. Versnipperde populaties komen voor in het zuiden en oosten in de provincies Limburg, Noord-Brabant, Zeeuws-Vlaanderen; de Achterhoek in Gelderland heeft de grootste populatie van het land, doorlopend in de populatie in Oost-Twente in Overijssel.