Dive-bombing hummingbirds add a twist to impress mates

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By Jason Bittel

In most North American hummingbirds, males court females by diving at them head on — but Costa’s hummingbirds (Calypte costae) perform their courtship dives off to the side. Researchers now find that this strategy allows the males to aim sounds at potential mates as if they were using a megaphone.

During high-speed courtship dives, males fan their tails at the last second to create a high-pitched chirp. The faster the dive, the more those tail feathers vibrate and the higher the pitch created by the would-be Romeos. Researchers suspect that females prefer higher-pitched dives, which results in various strategies to boost the frequency of the noise a male makes.

A study1 published on 12 April in Current Biology finds that male Costa’s hummingbirds can twist half of their tail feathers in the direction of the female, manipulating the volume and pitch of their chirps (see video). The researchers suspect that the targeted noise also masks audio cues that the females can use to judge how fast the males are diving.

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3 COMMENTS

  1. @OP – In most North American hummingbirds, males court females by diving at them head on

    Hummingbirds are fiercely territorial and will dive at any intruders (including other birds or animals,), found in their territory, so this is perhaps a variation of this behaviour!

  2. The Doppler effect is a very impressive thing. It’s just NASCAR for hummingbirds. Of course it drives all the chicks crazy. Give them a few hundred thousand years of evolution and they’ll be selling nectar at the track to all the fat hummingbirds.

  3. @OP

    Researchers suspect that females prefer…….

    Sounds more like the females are scared shitless and have to be comforted afterwards. These switches have to be switched on somehow I suppose.

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