Europe Faces Invasive Frog

Frogs species may be finely adapted to their environments, but new research shows immigrant species can quickly upset nature's delicate balancing act.

Over time, scientists counted water frog populations in Europe and noticed that the marsh frog (Rana ridibunda) can crowd out indigenous species like Graf’s hybrid frog (Rana grafi) and the Iberian water frog (Rana perezi).

The marsh frog likely comes from leftover frogs shipped in from Asia to prepare delicacies like frog legs.

Because the marsh frog lives longer, grows faster and bears more eggs than the two native species, it's been able to out-compete the other frogs, according to a study detailed in the journal Comptes Rendus Biologies.

Invasive frog numbers increase even further because it can mate with the Graf and Iberian frogs—effectively diluting their gene pools.

—LiveScience Staff

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Credit: Dirk Schmeller/Helmholtz Centre for Environmental Research (UFZ); Tilo Arnhold