As there was no response to my request for information of the plumage variation, I assume that there is no information. Since sending the email, I have read a 1976 article in Emu by G.L. Maclean (Vol 76, pp 207-215) in which he concluded
that there is a non-breeding plumage. What he initially thought were immature birds, he concluded were non-breeding birds when the proportion in the birds he was studying steadily rose to 85-95%, and from the examination of four birds with this plumage, which
were all adults. Non-breeding birds had no black markings on head and chest, or only a trace of them, but the central markings of their dorsal feathers were somewhat paler. He suggested more work was required to distinguish non-breeding adults from immature
birds.
Steve
From: Wallaces
[
Sent: Friday, 20 October 2017 3:14 PM
To: Canberra birds
Subject: Inland Dotterel plumage variation
Since seeing a group of 14 Inland Dotterel near Quandialla on Tuesday, I have been trying to understand the plumage variation I saw. There is plenty of variation visible but is it just individual plumage variation or due to differences
in age, sex or breeding condition. Instead of helping, the descriptions in the usual references are more inconsistent than for any other species I can recall - see table below.
The clearest difference shown in the attached picture is that some have a white face and the area around the ‘Y’ while other birds have a tan face and area around the ‘Y’. The colour on the back also varies with some birds having brown
centres to their feathers surrounded by a tan colour with others have black centres to the feathers with a more whitish/grey surrounds. In some the black areas are not as defined as they are on other birds.
If anyone has more experience with this species (this is my first encounter) or any other information which could help understand the variation, I would appreciate knowing. Video of the birds
http://www.hbw.com/ibc/1424277.
Thanks
Steve
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Source
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Male/Female
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Breeding/non breeding
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Immature/Juvenile
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The Australian Bird Guide (2017)
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No difference described
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NB - Dark lines through eyes and on underparts become duller and fainter, may be completely lost from underparts
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J – duller than adult non-breeding, with pale centres to feathers of upperparts
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Waders by Hollands and Milton (2012)
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Female: similar [to male] but duller
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Similar
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J - Duller. Black ‘halter’ indistinct or absent.
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Bird in the Hand (v2) (information source - HANZAB) (extracted from
http://www.absa.asn.au/
12 Sep 2017)
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Female: Black and over crown and strip below eyes mottled by buff. ‘Y’ on breast narrower than male & less clearly defined with broad buff edges to feathers;
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No difference described
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J – orange-brown to orange buff with no “Y”, to indistinct traces of a “V” (not “Y”)
Second immature - mottled untidy looking “Y” with buff edges to feathers
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Birdlife Australia website (20 Oct 2017)
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No difference described
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No difference described
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J -
duller, paler and less streaked with little or no black markings evident
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Handbook of birds of the world (www.hbw.com accessed 20 Oct 2017)
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Sexes alike
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NB - apparently almost lacks the eye-bar and breast
band
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J -
like non-breeding adult, i.e. showing just traces of dark face and collar.
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The Field Guide to the Birds of Australia, Pizzey and Knight (8th edition 2007)
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No difference described
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No difference described
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I – breast marking indistinct or is plain buff-white below, running to chestnut on flanks
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Field Guide to Australian Birds, Morcombe (2000)
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No difference described
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NB – may show some loss of colour but distinctive dark markings … always present
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J – probable that all birds in pale plumage are juveniles.
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