Hi Everyone,
Below are this week's figures from our 20-2-03 survey on a falling tide. One
of the continuing frustrations of our surveys is the high number of
unidentified terns we see flying in in the last couple of hours before dark.
This is partly because we have to have the hire boat back by a given time,
and also because even if we were still out there on the sandbanks at last
light, the rate of arrival of birds is so great that we would have a devil
of a time to get a reasonable assessment of numbers, let alone a breakdown
of species. The way we do it gives us a more accurate total.
So, just for fun, this week I did something one should not do. I took the
proportions of birds actually seen in the counted flock of some 13,000 at
rest on the sandbank during the afternoon, and extended those figures into
the unidentified tern total for the day. If the proportions of unidentified
terns arriving were consistent with those counted during the afternoon, we
would have had the following result:
hypothetically:
Common Tern 71% 29646
White-winged Black Tern 15% 6264
Little Tern 14% 5845
Total terns 41755
Anyway, here's what we actually saw:
Common Tern 11808
Crested Tern 135
Little Tern 2327
White-winged Tern 2495
Silver Gull 325
Terns unidentified 24990
Eastern Curlew 2
Whimbrel 4
Bar-tailed Godwit 155
Great Knot 3
Curlew Sandpiper 51
Red-necked Stint 14
Greater Sand Plover 45
Lesser Sand Plover 4
Red-capped Plover 29
Australian Pelican 29
Pied Cormorant 23
Little Black Cormorant 2
Brahminy Kite 1
Osprey 1
White-bellied Sea-Eagle 1
Total for day 42444
Total terns 41755
Total other birds 689
I held the final tern identification day on Saturday in dubious weather.
Because of the wet weather, the participants saw something none had seen on
the previous days - vast flocks of terns. We have often observed that the
terns are more reluctant to go fishing when the weather is dull or raining.
On Saturday there could have been 15,000 or more terns on the banks. I
didn't attempt to count.
Cheers,
Jill
--
Jill Dening
Sunshine Coast, Qld
26º 51' 152º 56'
Ph (07) 5494 0994
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