Songbirds are wonderful creatures, they warble to attract a potential mate and to defend its territory. But males are more aggressive when a rival sings better; a new study published in the Journal Ibis International Journal of Avian Science shows. The tui (Prosthemadera novaeseelandiae) in New Zealand is really territorial. “There are flowering and fruiting trees year round in New Zealand, so the tui always have resources to defend,” says Samuel Hill at Massey University in Auckland, New Zealand and author of the study.
As singing is so exhausting for songbirds, the males would sing longer to show off their endurance and skill to females to impress them. In zebra finches, for example, the females would choose males that can sing difficult songs. Hill says that the complexity of a male’s song is possibly a proxy for a male’s cognitive ability and body condition.
So, to see how the males would react to strong competitors, researchers studied 12 tui territories in Tawharanui Regional Park, near the tip of New Zealand. They used a speaker to play simple and complex birdsongs, and a control song from different species. The simple and control song was played for three minutes on the edge of the bird’s territory, and the complex songs were nearly twice as long as the simple songs and had more types of syllables.
After the complex songs were played, the male tui would approach the speaker faster than simple songs. In addition to that, they got on average 0.3 meters away after the complex songs were played compared to almost 6.3 meters for simple songs. Also, the males responded with more types of syllables and lasted longer than the speakers.
According to Kazuhara Sasahara at Nagoya University in Japan who isn’t part of the study, Hill’s research may be the first to show a direct link the aggressive responses and song complexity in males.
So, tweet tweet?
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