Algemeen

Pilzseuche jetzt auch bei Schlangen

Nach den Amphibien jetzt die Reptilien: Jetzt haben Frank Burbrink vom American Museum of Natural History in New York und seine Kollegen eine weitere Pilzseuche entdeckt – und eine weitere gefährdete Tiergruppe: die Schlangen. Im Osten der USA sind bereits 23 Schlangenarten befallen, darunter drei Arten, die in Europa vorkommen. Das Bedrohliche daran: Der Erregerpilz scheint weder auf bestimmte Schlangengruppen noch auf spezielle Lebensräume oder Lebensweisen spezialisiert zu sein.

Pesticiden bedreigen amfibieën

Uit wetenschappelijk onderzoek blijkt dat pesticiden en andere chemicaliën een significante rol spelen in de wereldwijde achteruitgang van amfibieën, zoals kikkers. De Duitse en Zwitserse wetenschappers achter de studie zeggen in het Britse dagblad The Guardian dat het zowel “verbazingwekkend” als “alarmerend” is dat veelvoorkomende pesticiden zo giftig kunnen zijn, en dat in dosissen die goedgekeurd zijn door overheden. “Je zou niet denken dat producten, die geregistreerd zijn op de markt, zo’n giftig effect hebben”, zegt Carsten Brühl van de Duitse universiteit Koblenz-Landau.

Der Grasfrosch ist zunehmend gefährdet

Die Deutsche Gesellschaft für Herpetologie und Terrarienkunde (DGHT) hat den Grasfrosch (Rana temporaria) zum Lurch des Jahres 2018 ernannt. Die Arbeitsgemeinschaft Fledermaus- und Amphibienschutz (AGFA) Seligenstadt und Mainhausen hat sich deshalb für nächstes Jahr die Kartierung, Zustandsbewertung, Dokumentation und eine mit der Naturschutzbehörde und dem Forst abgestimmte Pflege der Gewässer im Waldgebiet zum Ziel gesetzt.

Study provides insights for combating devastating amphibian disease

Amphibian chytridiomycosis, caused by infection with the Batrachochytrium dendrobatidis fungus, is the most devastating vertebrate disease on record. The fungus infects more than 600 species of amphibian and has been implicated as the primary cause of decline in more than 200 species. A new Animal Conservation study indicates that the common eastern froglet, Crinia signifera, can carry infections without experiencing mortality. Therefore, the presence of the froglets at sites where species have become threatened or extinct inhibits efforts to reintroduce these species.

The Resilience of the Bee Hive

A recent assessment of higher tier studies on the toxicity and risks of neonics in honeybees by Solomon and Stephenson reported a colony-level NOAEC of 25 μg/kg (ppb) for imidacloprid and clothianidin. The toxicity of these insecticides to honeybees is however known to be reinforced with chronic exposure, and extrapolation of time-to lethal-effect toxicity plots compiled from published studies indicate that an imidacloprid level of 0.25 ppb, i.e. one-hundredth of the reported colony NOAEC, would kill a large proportion of bees nearing the end of their life.

Dramatischer Rückgang bei Amphibien im Salzburgerland

Vor wenigen Wochen erst sorgte eine Untersuchung über das Insektensterben in Deutschland auch über die Wissenschaftsseiten hinaus für einige Aufregung. Wenn es aber weniger Insekten gibt, dann müssen auch ihre Fressfeinde darunter leiden. Und genau das bestätigt nun eine Studie der Salzburger Herpetologen Martin Kyek, Peter Kaufmann und Robert Lindner (Haus der Natur in Salzburg).

Insect decline: the biodiversity of the entire world is at stake

Bees and butterflies are experiencing widespread population decline, creating public concern in recent years. Data collected in Germany suggest that it’s not just bees and butterflies at risk: insect populations overall have plummeted by more than 75 percent since 1989. Scientists have known about the population decline for several years. However, they didn’t know how many species were declining, and they didn’t expect it to be happening so fast.

In the last two decades there have been an alarming number of amphibian extinctions

Amphibians, a unique group of vertebrates containing over 7,000 known species, are threatened worldwide. A 2004 global assessment found that nearly one-third (32%) of the world's amphibians are threatened, representing 1,856 species. Amphibians have existed on earth for over 300 million years, yet in just the last two decades there have been an alarming number of extinctions, nearly 168 species are believed to have gone extinct and at least 2,469 (43%) more have populations that are declining.

The Western Ghats have been witnessing an unusual number of frogs with deformities

Scientists and public health experts are alarmed by the phenomenon, which they suspect to be symptomatic of underlying toxicity in the environment and the food chain. “Missing eyes, deformed hind legs, missing limbs, extra limbs, partial limbs, limbs that are bent or bony, and abnormally thin or weak limbs are some of the reported frog abnormalities in the Western ghats,” said Dr. S. Muralidharan from the Division of Ecotoxicology at Salim Ali Centre for Ornithology & Natural History.

Emerging disease further jeopardizes North American frogs

A deadly amphibian disease called severe Perkinsea infections, or SPI, is the cause of many large-scale frog die-offs in the United States, according to a new study by the U.S. Geological Survey. Frogs and salamanders are currently among the most threatened groups of animals on the planet. The two most common frog diseases, chytridiomycosis and ranavirus infection , are linked to frog population declines worldwide. The new study suggests that that SPI is the third most common infectious disease of frogs.