Hi Everyone,
At the end of this message is a list of all species and numbers seen on the
Caloundra sandbanks in our weekly survey of 14/3/03. Numbers of migrant
terns were reached, as usual in peak flock times, by conducting multiple
sub-samples. In this case we had 8,800 migrant terns at rest with 68%
Common, 18% White-winged Black, and 14% Littles from 10 sub-samples. The
unidentified terns are all migrants of the listed three species.
This is our third year of monitoring the peak pre-migration flocks weekly,
but this year for the first time, I am not so sure of the numbers present at
times in Caloundra. I am happy that there were at least as many as we
recorded, but as we have had to work several times in lousy weather (heavy
cloud, winds, rain, all of which diminish our depth of field) I can't really
say I am confident that we got them all. We are but human, and have to live
with that.
Little Terns are increasingly showing breeding plumage. We did a sample
showing 74 with yellow on bill, and 24 with full black bills. No
multi-flagged Littles indicates a dearth of that population on Friday.
Commons are not as advanced as the Littles into breeding plumage, and only
this week we saw the first Common with an almost full black breeding cap,
plus a few with slightly greying breasts. White-wings are a real mess as
they acquire their breeding plumage, but there's worse to come before they
take on their beautiful black plumage next month. When the flock takes to
the sky now, the White-wings stand out with their growing black underwing
bar.
Another point that's got us intrigued. In the two previous corresponding
periods, we have seen plenty of begging from juvenile Crested Terns. This
year we have had plenty of juveniles present, but not once have we observed
juvenile begging. Plenty of food out there this year? The juvs arrived at
the expected time, so I don't think they would be any older than is usual
when they arrived, and besides, we have observed begging for months after
arrival from the breeding islands.
We have always noted activities which disturb the flocks. When it comes to
human activity, the most certain trigger to lift a flock is a walking human.
However, water-borne activities barely raised an avian eyebrow until the
advent of kite-surfing. Kite-surfing really upsets roosting terns and
waders, because the kite can swoop over the flock like a raptor, while the
person remains on the water at a distance from the flock. And it looks so
harmless.
Cheers,
Jill
Birds seen 14/3/03:
Caspian Tern 1
Common Tern 5984
Crested Tern 73
Gull-billed Tern 1
Little Tern 1232
White-winged Tern 1584
Silver Gull 473
Terns unidentified 12030
Eastern Curlew 27
Whimbrel 21
Bar-tailed Godwit 100
Curlew Sandpiper 52
Terek Sandpiper 6
Red-necked Stint 9
Grey-tailed Tattler 7
Greater Sand Plover 62
Lesser Sand Plover 6
Red-capped Plover 31
Double-banded Plover 1
Pacific Golden Plover 171 (I need to double-check this total)
Australian Pelican 51
Pied Cormorant 38
Great Cormorant 1
Little Black Cormorant 1
Egret spp 1
Whistling Kite 3
Totals for day all species 21966
--
Jill Dening
Sunshine Coast, Qld
26º 51' 152º 56'
Ph (07) 5494 0994
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