African tiger fish in the hunt of the swallow

2014/01/14 Carton Virto, Eider - Elhuyar Zientzia Iturria: Elhuyar aldizkaria

• Ekologia
• Zoologia

The recording was performed on South African artificial lake Schroda Dam. The tiger fish jumps under water and devours the swallow that flies near the surface. According to researchers from the South African University of North-West, this is the first time this type of behavior has been documented for tiger fish. For 60 years there have been references to the hunting of the swallow, but so far it has not been possible to gather evidence. The researchers continued for 15 days the tiger fish of the lagoon and, in view of the result, the swallows are a relatively common part of the fish diet.

The results of the observation have been published in the journal Journal of Fish Biology. According to the article, in the period of 15 days analyzed, about 20 successful smoothies daily have been observed, reaching a total of 300 goals captured by tiger fish (Hydrocynus vittatus). According to the researchers, these figures indicate that the hunting of swallows is not sporadic behavior, at least, among the tiger fish of this lake.

The researchers believe that such active swallow hunting may be due to a shortage of food in the countryside, since in the same article they claim that tiger fish from Lake Schroda Dam spend three times longer looking for food than the rest of the local populations.

The researchers have documented two hunting strategies: sometimes they continue below the surface of the water the swallow that is over and then jumped; and sometimes they jumped directly from deeper depth. According to the data obtained by the researchers, the latter is the most successful technique.

The track for the recording of the smoothies was provided to the researchers by the extraordinary activity of the fish of midnight: in summer, between 8 and 12, they circulated very active outside of the usual feeders and shelters, time that coincided with the time when the migratory swallows flew on the lake to eat and drink.