Anne.
The terms juvenile (more correctly juvenal) and immature have
different meanings.
Juvenal is the plumage that of a young bird that comes in immediately
after, or succeeding, its natal down. The juvenal plumage is the first
in the life of a bird that is composed of true contour feathers.
Generaly juvenal plumage is the plumage that most (non precocial)
birds leave the nest with.
Immature plumage (or first year plumage in banding terms) is the
plumage where some or all of the juvanal feathers have moulted,
generally body or covert feathers, some species carry some juvinal
feathers for up to 3 months. These Juveal feathers are good ageing
characters. Technically a bird is immature when it looses its first
juvinal feather.
Regards
Alan Leishman,
Royal Botanic Gardens
Mrs Macquaries Road, Sydney
______________________________ Reply Separator _________________________________
Subject: birding-aus juvenile or immature?
Author: van Roekel <> at mailgate
Date: 19/4/99 23:30
Hello Aus-birders,
Recently I was on Parson's Beach in South Australia looking for the Hooded
Plover. I found a bird with all the right characterisitics except that the
hood was grey instead of black. Slater's Field Guide which I had with me had
a picture of a juvenile, which had bits of brown around the head and didn't
look much like my bird at all. When I got home I consulted Pizzey and Knight
and found a picute labelled immature exactly corresponding to my bird. I
would greatly appreciate some clarification of when a bird is juvenile and
when immature or whether it can be both at once.
Many thanks,
Anne van Roekel.
To unsubscribe from this list, please send a message to
Include ONLY "unsubscribe birding-aus" in the message body (without the
quotes)
To unsubscribe from this list, please send a message to
Include ONLY "unsubscribe birding-aus" in the message body (without the
quotes)
|
