I agree with Ian's point about tail feathers being more 'sheddable'. In
my bird banding experience, it certainly seems that tail feathers come
out a bit easier than other feathers. I think this is particularly so
closer to the time of regular moult, when it seems as though all you
have to do is touch the tail and feathers will fall out. I have
witnessed a couple of examples of birds losing all of their tail
feathers in one go, but still being able to fly (although looking very
quail-like in doing so).
I disagree with Ian in that the bird must wait until the next scheduled
moult for those feathers to regrow. A feather lost because of damage is
replaced pretty much straight away and grows over a period of up to
several weeks. The plucking of a feather will stimulate the follicle to
produce another feather, but cutting or damage to the mature feather
(with the shaft still in the follicle) will not cause a new feather to
grow.
A good example of single feather replacement was the female Grey-crowned
Babbler at the golf course last year. She was growing a single tail
feather that was definitely not part of a regular moult. The tail
feather had a large white tip, so the growth over several days was
easily observed.
Cheers
Anthony
-----Original Message-----
From: Ian Fraser
Sent: Wednesday, 19 January 2005 6:53 PM
To: chat line
Subject: Escape mechanism?
It may well be that tail feathers are designed to be dropped (or at
least
able to be pulled out readily easily) in an emergency. Certainly they
seem
more 'sheddable' than flight feathers, for instance. However the bird
would
then have to do without them until next moult. On the other hand it
could
perform the trick once a year, unlike a gecko or skink which can only do
it
once a lifetime.
cheers
Ian
---
Ian Fraser,
Environment Tours; Vertego Environmental Wordsmithing
GPO Box 3268, Canberra, ACT 2601
ph: 02 6249 1560 fax: 02 6247 3227
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