G'day Jill,
If you remember, we also communicated recently with regard to the
identification of Double-banded Plovers (I include a synopsis below). But
you've raised a few interesting points. Even though you've said that "Clive
Minton has settled the matter in my mind", I am still curious, if not
puzzled.
You have said -
1. "DBPL do indeed lose their breastbands entirely during the winter."
Whilst this may be true, the non-breeding plumage of the nominate race which
we see in Australia is of short duration, covering the primary moult and a
short period afterwards (see Shorebirds, Hayman et al). I am still seeing a
semblance of a breastband on some birds and it is now May. No doubt birds
lose their breastbands, and subsequently regain them, at different times
throughout the austral winter, so it would be inadvisable to suggest that if
a bird has a breastband in winter it is not a Double-banded Plover.
2. "Furthermore, the Pizzey yellowish-buff head feature for the immature
depiction is probably closer to an average non-breeding adult. The
yellowish head markings are not an indicator of immaturity. It is Clive's
opinion that it is extremely difficult in the field to separate the
immatures from the adults." If it is extremely difficult to separate
immatures from adults, how can you say that the Pizzey illustration is of an
adult, not an immature? And are we disregarding the feature that in an
immature the supercilium is larger and continues further behind the eye? I
was interested to note last month that all of the birds I saw with a more
pronounced supercilium were also those that had a more golden suffusion
around the head.
3. "Furthermore, I noticed that in the museum skins, almost every specimen
had some pale fringing to the feathers on the back and upperwing coverts."
Did you notice the colour of these fringes, as the adult is supposed to have
a warmer colour than the buffy-white of the immature? Or are we saying that
this also is a non-reliable feature? Also, I seem to remember you saying
that you identify the Caloundra Double-banded Plovers on the basis of their
pale fringes. This could lead to birds being mistakenly identified as
Double-banded Plovers, as there are certainly both Lesser and Greater
Sandplovers around at the moment with extremely visible pale fringes.
Cheers - Trevor.
Synopsis of previous communications (written 17/4, 18/4) :-
I'm suspicious that, although the extent of the breast band may not be
conclusive, the majority of our birds could be youngsters:-
- They show pale fringes to their mantle / tertials / coverts giving the
speckled appearance you described. My guess is that an adult in winter
would have worn any fringes away, giving a much blander appearance. This
would be before any moult into breeding plumage. Note that young
sandplovers can also show these pale fringes.
- My recollection is that most of our birds have a prominent supercilium,
which is consistent with young birds.
- They certainly have an attractive golden hue, especially about the head.I
think that this is lost later on during our winter, but by then I'm always
admiring their breasts (ahem!)
- I'll get to Kakadu Beach tomorrow - I also want to have a good look at the
nape colour of our birds.
Followed by .....
- Interesting! I would guess that about 2/3 of the Double-bandeds were
immatures with the rest being adults. The adults showed less golden, less
supercilium and less mottling (although certainly some). Most adults showed
an upper breast band to some degree, although it varied greatly in size.
Some showed various degrees of a second band, some with a bit of colour.
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