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feather growth rate

Here is the complete version. Somehow an unfinished, uncorrected version
was mailed earlier.


This was "Pterosaur & Birds" that became sort of an ecological threat.
Feathers do not grow at a constant rate in all birds, regardless of body
mass. Even within species it can vary. The figure of ca 1mm/day was
probably derived from studies on chickens and may vary during the entire
growth. In larger birds primary feathers of the Wandering Albatross,
Barrow  et al.,(1999)reported that "Maximum growth rates were similar
(4.5 mm/day) for all feathers and between sexes, although primaries of
males were significantly longer than those of females." In this study
they found that the daily growth rate varies among feathers on
individuals and between the same feathers on males and females. BTW age
at fledging in this species averaged about 280 days. Note that in a
typical passerine of much smaller size the age at fledging may be on the
order of 20 days! Barrow, et al submit that "Fledging periods for
Wandering Albatross chicks may be constrained by the time required to row
a full set of primaries".

Alan H Brush
92 High Street
Mystic, CT. 06355
(860) 572-1717