At 08:24 AM 10/06/2008, Greg & Val Clancy wrote:
I am curious to know why you believe that the Dollarbird is a 'sub-adult'?
It look like a juvenile to me. I suppose it depends upon what your
definition off sub-adult is. Certainly a juvenile is a 'sub-adult' if you
call anything younger than an adult a 'sub-adult' but I don't. I usually
reserve the term for a bird that is close to assuming full adult plumage,
i.e. a late stage immature.
A juvenile bird is one that is still in the plumage that it had when it
left the nest.
A juvenile Dollarbird has a black bill. This base of the bill on this bird
has started to attain adult colour. The head of a juvenile is
darker. This bird has a brown head very close to adult plumage. A
juvenile doesn't have the blue on the lower throat / upper breast. This
bird has adult plumage here. This bird has more advanced plumage even than
'immatures' illustrated in several texts. So it is older than immature,
but not fully adult. i.e. it is a late stage immature. Ron Johnstone at
the WA Museum agrees.
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Frank O'Connor Birding WA http://birdingwa.iinet.net.au
Phone : (08) 9386 5694 Email :
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