13 April 2010

Identification pitfalls: Aix ducks

Figure 1: Flock of captive galericulata from their native China and close-up of sponsa (origin of specimen unknown).

As can be seen above, whilst superficially similar in female plumages, these two species are best told apart by differences in overall plumage tone, presence/absence of striations at sides of head and neck, extent of 'eye-patch' and eye-stripe, nail colour, shape of flank spotting, colour/glossiness of greater and median coverts, leg and body length and steepness of forehead. Ageing of galericulata best attempted with reference to head pattern and streaking on underparts; with sponsa accurate ageing achieved by cutting in half and counting the rings.

More photographs of the two species can be found by typing "plastic ducks" into Google or on page 103 of your newly arrived Birding World,... er,... shurely shome mishtake!

With thanks to Mr. Bonser (via Mr. Alfrey) for providing a reason to remove the plastic wrapping from my BW this month.

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