![]() ![]() ![]() This velocity suggests their body drag coefficient is less than 0.3. This is the highest known length-specific velocity attained by any vertebrate. After powering the initial stage of the dive by flapping, males folded their wings by their sides, at which point they reached an average maximum velocity of 385 body lengths s −1 (27.3 m s −1). Diving male Anna's hummingbirds were filmed with a combination of high-speed and conventional video cameras. I provide an example of an extreme display, the courtship dive of Anna's hummingbird ( Calypte anna). Just as female preferences can generate exaggerated male ornaments, female preferences for dynamic behaviours may cause males to perform courtship displays near intrinsic performance limits. Behavioural displays are a common feature of animal courtship. ![]()
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