In early May 2011, one of the pair of Spotted Doves that has been visiting my garden regularly arrived with only a single tail feather. Its partner still has the full complement of tail feathers. This single-tailed dove is relatively tame, entering the house whenever I forgets to feed it. It allows me to approach within half a metre from it. Any nearer and it would run away. But it can still fly, although clumsily. Alter all, flight depends mainly on the wing feathers. Tail feathers on the other hand play an important role in controlled landing.
Obviously the loss of so many tail feathers at the same time in this dove was probably a result of shock moult, also known as fright moult. The bird could have been grabbed by a predator, most probably a human.
Aviculturist Lee Chiu San agrees that the tail feathers could have been lost due to the dove trying to escape capture. According to him, ”…some birds have feathers securely anchored. Others have feathers that come off very easily. This could be a defence mechanism. A very general rule of thumb is, if the bird is able to bite back, its feathers do not detach easily. If the bird does not have the ability to bite, it is better to lose the feathers while the rest of the bird gets away rather than continue to be stuck to the feathers and be eaten. In aviculture, I try as far as possible not to handle doves because they shed feathers like snowstorms.”
YC Wee & Lee Chiu San
Total loss of tail feathers seem to affect the birds ability to gain altitude with distance flown.
I once tried to help a starling that appeared a bit lost and without its entire set of tail feathers.
I only managed to fly up to a chest high bush with tremendous effort. Finally it made a straight flight across the road and only managed to gain not more than 1-2 metres in height despite very strong wing strokes.
Its ability to stear precisely as it approaces to land was also compromised by the loss of the tail which resulted in a very clumsy landing, totally missing the first perch it had targeted.
For Spotted Doves, the tail feathers seem to play smaller part in high speed cruise flight. The tail acts as a speed brake when it needs to slow down rapidly and at the same time act as a rudder / elevator to maneuver at low speeds.
Thanks Jeremy. Good to have this info.
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