Algemeen

Die Zahlen sind alarmierend: 40 bis 60 Prozent weniger Amphibien als sonst haben Helfer des Bund Naturschutz bei der diesjährigen Krötenwanderung gezählt. Warum sind es auf einmal nur so wenige? "Es könnte für Bayerns Amphibien bereits fünf vor zwölf sein", warnt Kai Frobel vom Bund Naturschutz in Bayern. Die Zahl der Frösche, Kröten und anderer Amphibien ist in diesem Jahr gravierend eingebrochen. In den elf bislang ausgewerteten Städten und Kreisen sind es 40 bis 60 Prozent weniger als sonst. In den Landkreisen Rosenheim und Straubing-Bogen teilweise sogar 90 Prozent.

Experts from Suffolk Wildlife Trust, Buglife and the RSPB have all pointed to species in danger of disappearing from East Anglia. They include stone curlew - only 202 pairs nested in the East of England last year; the shrill carder bee - common in the region 25 years ago but now found only in the Thames Gateway area; and the crested cow-wheat - a plant limited to a small number of roadside verges because grassland has disappeared to farming or construction. Indeed, habitat destruction and human disturbance are cited as the two most common reasons these species are on the brink.

Pesticide use is driving an “alarming” decline in the world’s insects that could have a “catastrophic” impact on nature’s ecosystems, researchers have warned. More than 40 per cent of insect species are at risk of extinction with decades, with climate change and pollution also to blame, according to a global scientific review. Their numbers are plummeting so precipitously that almost all insects could vanish within a century, the study found.

When American entomologist Bradford Lister first visited El Yunque National Forest in Puerto Rico in 1976, little did he know that a long-term study he was about to embark on would, 40 years later, reveal a “hyperalarming” new reality. In those decades, populations of arthropods, including insects and creepy crawlies like spiders and centipedes, had plunged by an almost unimaginable 98% in El Yunque, the only tropical rainforest within the US National Forest System.

Auf Einladung des Bund für Umwelt und Naturschutz Deutschland (BUND) referierte der Insektenforscher Thomas Hörren vom Entomologischen Verein Krefeld (EVK) im Möllner Quellenhof vor 90 Besuchern über deren bahnbrechende Studie zum Thema “Rückgang der Insekten-Biodiversität”. An zahlreichen Standorten ausschließlich in Schutzgebieten hatte der EVK 27 Jahre lang die Insektenfauna untersucht. Aufgrund des enormer Datenbestand und der wissenschaftlichen Methodik waren die Entomologen in der Lage, nicht nur den schleichenden Verlust an Arten, sondern auch an Insekten-Biomasse zu dokumentieren.

Neonicotinoids are widely known for their link to declining pollinator populations, but new research finds that the ill effects of these chemicals also extends to amphibian populations. In a study published late last month, scientists from the National Wildlife Research Center in Ottawa, Canada found that chronic exposure to real-world levels of the neonicotinoid imidacloprid limits the ability of juvenile wood frogs to escape a predator attack. This research adds additional evidence that neonicotinoids are harming aquatic food chains.

Arthropods, invertebrates including insects that have external skeletons, are declining at an alarming rate. While the tropics harbor the majority of arthropod species, little is known about trends in their abundance. We compared arthropod biomass in Puerto Rico’s Luquillo rainforest with data taken during the 1970s and found that biomass had fallen 10 to 60 times. Our analyses revealed synchronous declines in the lizards, frogs, and birds that eat arthropods.