'Freshwater killer whale' Catfish hunt pigeons: video
European catfish have been observed hunting pigeons - on land.
According to the study in PloS One, what the Catfish do is they actually beach themselves to catch pigeons as they land on the shore to rest and rehydrate from flying.
"The beaching behaviour was quick, lasting from less than one second to no more than 4 seconds. The attacks were systematically triggered by active pigeons. Indeed, motionless pigeons, even very closed to the European catfish, were never attacked.
"Before the attack, European catfish were observed to exhibit erected upper jaw barbels on the upper jaw when they approach pigeons, suggesting that water vibrations, rather than visual cues, were used to detect and attack the prey," the researchers wrote.
The catfish that do this tend to be alien species - having been introduced over a period of years from east of the Rhine river to western waters. The adaption has not, to the scientists' knowledge been seen in the species' native range, suggesting that it is an adaption to its new habitat, that only some of the catfish engage in.
"These findings suggest that this new predation behaviour might represent an extreme example of the ability of introduced species to adapt to a new environment that could have unexpected implications for consumer-resources dynamics and ecosystem functioning that deserve further investigations," the researchers concluded.