25m Tons of Spiders exist đź•·

Neue Studie von Martin Nyffelervon der Uni Basel und Klaus Birkhofer von der Uni Lund in Schweden, die den Verzehr an Biomasse durch Spinnen ausgerechnet haben und dazu die Masse der Viecher ermittelten. Es gibt 25 Millionen Tonnen Spinnen auf der Welt, die genau soviel Tiere verspeisen, wie der Mensch (und wie Wale), 400 bis 800 Tonnen. Die im Bild abgebildeten Tiere essen davon ungefähr die Hälfte, darunter Hundewelpen, Ratten und Koalas. Now you know. (Also, Koalas suck. [But they don't suck as much as spiders. Spiders suck most.] via Marginal Revolution)

In research published this week in the Science of Nature, Martin Nyffeler of the University of Basel, in Switzerland, and Klaus Birkhofer of Lund University, in Sweden, attempt to put some numbers on spiders’ dining habits. Starting with the available data on the mass of spiders found per square metre in Earth’s main habitat types—forests, grasslands, fields of crops and so on, they calculated the amount of prey required in each habitat to support the weight of spiders there, based on spiders’ known food requirements per unit of body weight. That done, they extrapolated their habitat-based results to the whole planet, in light of what is known about the total areas of such habitats.

Their conclusion was that there are 25m tonnes of spiders around the world and that, collectively, these arachnids consume between 400m and 800m tonnes of animal prey every year. This puts spiders in the same predatory league as humans as a species, and whales as a group. Each of these consumes, on an annual basis, in the region of 400m tonnes of other animals.

Hier ein erwägenswerter Teil der 25 Millionen Tonnen an Spinnengezeucht: