24 January 2014
African Tigerfish jump out of the water . . . into the air . . . and catch birds in flight. Tigerfish, in a storage lake for the Schroda Dam in South Africa, were caught, on video, grabbing barn swallows out of the air.
Sometimes called the “African piranha,” the tigerfish is a scary looking fish. [image] However, the tigerfish and piranha are two different species with the tigerfish winning contest as the bigger and meaner of the two. Like piranhas, tigerfish have “interlocking, razor-sharp teeth”, “are … extremely aggressive … predators”, and “often hunt in groups.” Both species have been known to attack humans. But unlike the relatively small piranha, an individual tigerfish weighs about 110 pounds.
The story of the tigerfish jumping out the water and grabbing birds, in flight, has been around since the 1940’s. But, for the first time, an “air-feeding” tigerfish has been caught on video.
Nico Smit, director of the Unit for Environmental Sciences and Management at North-West University in Potchefstroom, South Africa, was part of the team that caught the tigerfish feeding on birds. He said that the whole “event” happens so fast that it took a while before the researchers were sure what they were seeing.
It didn’t just happen fast. It happened often. They saw 20 “catches” the first day and about 300 during the next two weeks. The “event” was caught on video for the first time by team member Francois Jacobs. The team’s findings were published in the Journal of Fish Biology and Nature.com.
The tigerfish favors the twilight as the time of day for hunting birds in flight. This fish has two varied approaches to the hunt. Sometimes, the tiger will swim near the surface of the water following the birds, in flight, before jumping up into the air to make a catch. Other times, the fish will lurk in the deeper water tracking the birds. Then, it will leap out of the water and ambush a bird as it flies by.
Smit is amazed at the skill displayed by the fish in spotting and pacing the birds from the water. Not only does the fish have to estimate and exceed the birds’ speed, but the tiger has to compensate for the light refraction in water. This is quite a trick. The angle of the light changes when it passes from the air into the water. This makes estimating the location and speed of objects in the air a lot tougher.
This has been quite a year for videos catching aquatic animals feeding out of the water. First, Julien Cucherousset of Paul Sabatier University caught catfish on video in France’s River Tarn as they practiced their recently acquired skill of jumping out of the water to grab and eat pigeons wandering on shore. Then, an octopus was caught on video leaving the ocean for a stroll on a California beach in search of meal. And, now, a fish leaps into the air to catch birds — in flight!
Where will it end?
Maybe it hasn’t.
In another recent “photo first,” Jun Yamamoto of Hokkaido University and his team recorded squid leaping out of the ocean just off the coast of Japan. These “flying” squid travel almost 100 feet before reentering their water. Not only do these flyers extend their legs and gills, like wings, to stay airborne, but they actually flap their fins for some added “bird-like” lift.
You have to wonder (or worry) what’s going to be walking or flying out of the water next.
Other “Thursdays” about Animals: