Why do birds have long tails? Males often have far longer tails than females so the usual idea is that long tails have evolved because females prefer them. According to the theory, a male is likely to make a good mate and have 'good genes' if he is able to be active and healthy, despite being handicapped by extra-long feathers.
But the reason why birds have long tails may not be as simple as this, say British zoologists. It depends on the shape of the tail. Although in some species, tails are long because females prefer them that way, in other species tails are long for aerodynamic reasons.
Andrew Balmford, Adrian Thomas and Ian Jones of the University of Cambridge set out to discover if the long tails really are a burden which can be shouldered only by the fittest males. Using computer models, they calculated the lift and drag ...
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