© Cucherousset et al.

New research published in the open access e-journal ‘PLOS One’ demonstrates the learning capabilities of the giant catfish Silurus glanis, Europe’s largest freshwater fish.

The study was conducted in the River Tarn, southwestern France, where the species was introduced during the early 1980’s, and demonstrates how the catfish have learned to actively beach themselves in order to capture terrestrial birds.

Observation of the fish from a bridge crossing the river revealed that they hunt in shallow water close to a gravel island where birds, particularly pigeons, group together to drink and preen.

During 24 such surveys, 54 instances of beaching behaviour with partial or complete stranding were observed, of which 28% were successful, and in 40% of cases more than half of the fish’s body was outside of the water.

Only active pigeons were attacked with motionless individuals ignored, even when very close to the water and fish.

For further information please refer to the full, open access paper: Cucherousset, J., S. Boulêtreau, F. Azémar, A. Compin, M. Guillaume and F. Santoul. 2012.  “Freshwater Killer Whales”: Beaching Behavior of an Alien Fish to Hunt Land Birds.  PLoS ONE: 7(12): e50840