Humpback whales migrate after the cold latitudes to feed continue to perform lengthy courtship songs, forgetting about food, scientists have found.
Humpback whales are distinguished among other cetaceans complexity "songs" that they use in the breeding season. The song of the male consists of sounds and "phrases" in the range of 40 to 5000 Hz lasting an average of 6 to 35 minutes. However, in reality this type of whale has three clearly separated seasonal periods: proliferation, migration, feeding, which, according to the observations of scientists, never coincide in time.
But the authors of the study, which is published in the journal PLOS ONE, led by Alison Stimpert (Alison Stimpert) Research University of the United States Navy (Naval Postgraduate School — NPS) found that humpback whales use the mating songs and during feeding.
They followed up by ten humpback whales from the tropical latitudes where animals breed, to the Antarctic, where they annually migrate to rich plankton cold polar water supply. As it turned out, two of the ten whales continued to perform long and complex mating songs.
"We were surprised to hear mating songs in the Antarctic, where whales, as we know, only the feed. This song unusually intense and long — lasting up to an hour," — said Stimpert.
However, singing was the only manifestation of mating whales during the feeding period. While whales continued to dive, moving as if in search of food, choosing instead to have been busy singing. During the breeding season the whales sing, did not move and waiting for a partner.
Scientists still do not know the meaning of whale songs. Among the most common hypothesis — to attract females, repelling other males or "showdown" with the establishment of the hierarchy.