January 13, 2014
Elusive African Tiger Fish Preys On Flying Birds
Brett Smith for redOrbit.com - Your Universe Online
Stories of the African tiger fish preying on birds in mid-flight have been circulating for years and a research team from South Africa has finally captured evidence of this behavior, according to a new study in the Journal of Fish Biology.
“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,” study author Nico Smit told Nature News.
After confirming the behavior through images captured by his team – Smit, a director of environmental science management at North-West University in South Africa, said “the first reaction was one of pure joy, because we realized that we were spectators to something really incredible and unique.”
Although rumors of this predatory behavior have been circulating for around 70 years, Smit said his team of South African researchers was “never really convinced by the anecdotal reports.”
Smit said has team wasn’t even initially focused on finding the rumored behavior, but was instead looking into the migration and habitat use of the predatory fish in Schroda Dam, a man-made South African lake near the country’s border with Botswana and Zimbabwe. However, the team was able to capture as many as 20 successful fish strikes on flying barn swallows each day. These attacks ranged from the fish tracking their prey at the surface to the predator rising up from deeper water. One of these strikes they captured on video and posted to YouTube. The video has garnered over a half a million hits in its first four days on the web.
"The African tigerfish is one of the most amazing freshwater species in the world," Smit told BBC News. "It is a striking fish with beautiful markings on the body, bright red fins and vicious teeth."
The fish can grow up to several feet long and is considered a protected species in South Africa. The study team used radio tags to follow the movements of individual fish and discovered that they mostly prey on other fishes at dawn and dusk. During the day, tiger fish preferred to rest in deep, sheltered areas, the team said.
In the report, the researchers called for additional study on how this newly-discovered predatory behavior fits into the nutrient cycle around the South African lake.
While bass, eels, piranhas and pike are all freshwater species that prey on birds swimming on the surface of the water, the new study is the first evidence of a freshwater animal catching birds in flight. Smit noted that freshwater fish in African have largely been ignored by the scientific community.
“We hope that our findings will really focus the attention on the importance of basic freshwater research, and specifically fish behavior,” he said.
The most prominent feature of the tiger fish is its mouth full of sharp teeth. The fish has a relatively small dorsal fin and what has been described as ‘rainbow’ coloration. Like their relatives the piranha, tiger fish have a string of small bones connecting their air bladder and their inner ear, a physical feature that increases their sense of hearing.