In a stroke of fortune, a group of South African researchers surprised even themselves when they succeeded in documenting a bizarre behavior of the African tigerfish that, while reported for decades, had never been confirmed.
The scientists from North-West University in Potchefstroom, South Africa had the camera running when one of the fish leapt out of the water, plucking a migrant swallow from the air as it flew across the lake's surface.
"The whole action of jumping and catching the swallow in flight happens so incredibly quickly that after we first saw it, it took all of us a while to really fully comprehend what we had just seen," Nico Smit, director of the Unit for Environmental Sciences, told Nature. Smit said "the first reaction was one of pure joy, because we realized that we were spectators to something really incredible and unique."
In all, the researchers said they saw about 20 successful attacks on swallows every day they spent on the lake located in Mapungubwe National Park. According to the BBC, the scientists used radio tags to monitor the movement of a number of fish, determining that they mostly fed on other fish during the early morning and evening, withdrawing to rest during the day. The exception was when a fish would pop out of the water for a bird that flew too low.
"We hope that our findings will really focus the attention on the importance of basic freshwater research, and specifically fish behaviour," Smit said.
Other fish that are known to prey on birds include piranhas, bass, pike, sharks and monkfish.
The African tigerfish has declined in some rivers in southern Africa as a result of pollution and the construction of dams and other projects. Heavy fishing has also caused numbers to sag in some areas. Still, the International Union for Conservation of Nature lists the animal as "Least Concern," citing a general abundance.