Spent a couple of hours at Flat Rock, Ballina yesterday.
Common Terns
Most have dropped their outer primaries but haven't yet finished growing
them in again. PreAlternate molt evident in wing coverts and inner
primaries, but not much on the head/body, though a few had dark flecks on
the forehead or patchy grey on the underparts.
Little Terns
Most were "Asian" birds in preAlternate molt, some in complete Alternate
plumage as far as I could see. Nearly all had new, but not very fresh outer
primaries, but were still in active molt about P7/8, with the rest new and
fresh. No sign of molt in inner primaries.
A very small number of Australian breeders. One was a juvenal, still with
dark V's on the hindneck and scapulars. The upper parts were generally
markedly paler than in the majority of Little Terns present.
Another was flagged white over metal on the right leg and blue over green on
the left. It had P10-8 old, P7-6 freshish, P5 missing and the inner Ps
fresh. In preBasic molt, still with dark lores and speckles on forehead and
forecrown. Interestingly, the bill was generally dull yellow but palest and
cleanest on the tip.
Two other Little Terns also had bills which were palest on the tip. Both
these had a primary molt consistent with an Australian breeder, with the
outer primaries quite old and black but the rest newer, but not fresh. Two
other birds had darker bills, but stood out from the majority of birds by
having noticeably paler upperparts. Again, these seemed to be Aussy breeders
judging from the old primaries, with the outer 2 oldest.
This all raises a couple of questions. If Little Terns can have pale bill
tips and paler dorsal surfaces than most, then that won't help distinction
from Fairy Terns. Could I be seeing hybrids? My inclination is to think not,
because the birds with pale bill tips or pale backs looked otherwise like
typical Littles. I think it's more likely that at least some Littles
progress from dark tipped yellow bills through a stage where the black tip
is lost while the rest of the bill is largely yellow, then darken up all
over. Furthermore, I think it's quite likely that the paler upperparts could
be a result of fading. It's interesting that the juvenal showed paler
upperparts also. Any comments?
Overall:
Common Tern 100
Little tern 200
Crested Tern 100
Silver Gull 5
Large Sand-plover 30
Lesser Sand-plover 10
Red-necked Stint 50
Sanderling 42
Curlew Sandpiper 30
Turnstone 10
Sooty Oystercatcher 2
Chris Corben
www.hoarybat.com
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