Talking of Shovellers and the differences between the Northern and the
Australian spp, the two males don't look very similar in full breeding
plumage, but have a look in a European fieldguide, or that Croom Helm book
of Waterfowl, and note the juvenile plumage of the male Northern. Striking
isn't it?
[For those who don't have access to one of the above books the juvenile
male Northern looks very much like a streaky, splodgy adult male
Australian, even down to the BLUE head and white face-streak.]
I assume that thousands of years ago an ancestral population of Shovellers
split, with either the ancestors of the Australian Ss retaining juvenile
plumage into adulthood (neoteny), or the ancestors of the Northerns adding
a new phase beyond the previous adult plumage (the opposite of neoteny,
what's the word?).
John Leonard
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
John Leonard (Dr),
PO Box 243,
Woden, ACT 2606,
Australia
http://www.spirit.net.au/~jleonard
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
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