(Phys.org) —A team of researchers with North-West University in Potchefstroom, South Africa has for the first time captured on video, a freshwater fish leaping out of the water and into the air to grab a flying bird. The video was part of research the team was conducting on tigerfish in African lakes—their paper has been published in Journal of Fish Biology.
Many aquatic animals, including fish, have been seen grabbing birds, but in almost all instances, the birds are nabbed as they are sitting on the water or on shore near the water. In this new study, the researchers found that the tigerfish were able to use two different tactics to grab barn swallows—birds that are generally known for their inflight speed and agility. The tigerfish, which have large sharp teeth were observed leaping and catching birds while swimming just near the surface, and also when pushing up from deeper water. The video of one of the fish actually catching a bird was filmed near Schroda Dam, which has formed a lake on the Limpopo River—part of the Mapungubwe National Park in South Africa.
The team reports that they were skeptical of rumors about fish leaping out of the water to catch birds, and were merely looking to study the habitat and migration habits of tigerfish. They were all shocked, the team reports, when they saw the first incident. After studying the tigerfish for some time, they observed on average 20 instances a day of the fish leaping out of the water and successfully grabbing birds, which were pulled under the water and eaten. They found that the fish were able to leap as far as three feet out of the water.
Tigerfish are well-known in Africa—they're a prized game fish and are notoriously fierce predators. For years, there have been anecdotal reports of fish grabbing birds out of the air over lakes in Africa, but until now, no one has documented them doing so. The video unequivocally proves that the fish are able to catch birds in flight and the observations by the researchers indicate that it is a common occurrence. The researchers suggest that the tigerfish's abilities have gone unnoticed by scientists until now because so little research has been conducted on freshwater fish in Africa.
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More information: O'Brien, G. C., Jacobs, F., Evans, S. W. and Smit, N. J. (2014), First observation of African tigerfish Hydrocynus vittatus predating on barn swallows Hirundo rustica in flight. Journal of Fish Biology, 84: 263–266. doi: 10.1111/jfb.12278