Geolocator retrapping
Well we never thought for a minute that retrapping the Red and Great Knot and the
Greater Sand Plovers was going to be easy. However we didn’t think it would as
difficult as it was!
It was a hot, hard and frustrating 8 days. Setting nets and then sitting around (or if
you were a twinkler driving and walking around) for hours. Only to pick up the nets
and do it all again the next day! We could have caught ‘birds’ every day bar one but
we were after individuals carrying geolocators (geos) so we turned down numerous
opportunities for good catches. We had a few additional issues to contend with as
well. On day one a Peregrine Falcon disturbed a flock containing 3 geos and on day
2 a Black Falcon stooped on a flock just metres from the catch zone with 2 geo birds
in it. Then on day three a Hobby zoomed by to disturb a flock with one geo in it.
So day 4 loomed and we set the net way down the beach in an ‘all or nothing’
attempt. We ended up with 68 bids but more importantly 2 geo Greater Sand
Plovers. The success was mostly due to some brilliant close twinkling form Linda
Bird (no really that is her surname!)
31/10/2012
SPECIES
Greater Sand Plover
Gull-billed Tern
Lesser Sand Plover
Red-capped Plover
Red-necked Stint
Ruddy Turnstone
Silver Gull
TOTALS
AGE IN YEARS
NEW
7
19
0
17
4
5
2
54
RETRAP
7
3
1
2
1
0
0
14
1st
1
0
0
6
3
5
0
15
Known Age 2
2
1
0
0
0
0
0
3
2+
6
21
0
13
2
0
0
42
3+
5
0
1
0
0
0
2
8
TOTAL
14
22
1
19
5
5
2
68
While all this was going on Clive was of checking out the rest of the bay (each day)
for Great and Red Knot flocks. They are usually in the region of 13-15,000 Great
Knot and 2-3,000 Red Knot on the beaches at this time of year on these heights of
tide so you can imagine our dismay when Clive found about 4,000 birds IN TOTAL
OF ALL SPECIES with next to zero knots. Our only sensible guess is that the
localised rain we had experienced had filled some of the salt pans behind the
mangroves in the north east of the bay and that is where the birds were choosing to
roost.
On the day we finally caught birds that days reccy did show that some few thousand
birds including knots were back on the beaches. Still 3 more days of no catching
brought us to our last day. The usual scenario followed with thousands of birds on
the beach, in front of the net some of the time, at times being disturbed by birds of
prey, flying away, being gently coaxed back etc. Finally we had birds in front with
one geo and we fired. We got the bird, thankfully.
4/11/2012
SPECIES
Bar-tailed Godwit
Great Knot
Grey-tailed Tattler
Red Knot
TOTALS
AGE IN YEARS
NEW
18
89
1
3
111
RETRAP
7
20
0
1
28
1st
0
17
0
0
17
Known Age 2
5
16
0
1
22
2+
0
8
0
1
9
3+
20
68
1
2
91
TOTAL
25
109
1
4
139
From Ken Gosbell our technical guru.
The early results from the 2 geos on the Greater sand Plovers is:
JCU – A full track was obtained…. But see later.
Departs Broome 6 April and travels north, stopping in Java and Vietnam (as per
previous records)
On 24 April flies to breeding grounds in Northern China/Mongolian border (37N,
106E). Despite some glitches I can ascertain that it stays there until 24 June when it
starts its southward migration. It stops in Vietnam (probably) from 25 June to 15
August.
It returns to Broome 19 August.
The major glitch was a massive time shift on 29/4 and again on 29/5 which moves
the longitude 70 degrees to the west. This feature of the data has been noted on
almost all loggers on this species. We have concluded that it is most likely subject to
some strong electromagnetic field in the vicinity of the breeding grounds. It remains a
mystery!
JBP – A track was obtained up until 12 May when the logger stopped. Departs
Broome 9 April and again appears to stop over in Java and Vietnam. It flies to the
breeding grounds 2 May and the logger stops operating 12 May. However I suspect
it reached the breeding grounds as it got to 43N, 103E.
The Great Knot geo has had to go to the UK to see if it can be downloaded.
THESE RESULTS ARE PRELIMINARY.
A huge thank you to the team, both local and interstate, who joined us for the
catching. It was a huge effort for not so much reward but you don’t get things easy
when working with wildlife.
See below for more.
Scanning at 80 Mile Beach
On November 9, 10 and 11 Ady and I went to Anna Plains Station and on to the
beach of 80 Mile Beach to scan for birds we have already marked. This is a very
important component of shorebird studies and a huge amount of information can be
gathered from regular scanning work.
We got a huge swag of sightings of both colour-banded birds and engraved leg flag
(ELF) birds. And not just birds marked at 80 Mile beach or Roebuck Bay (see table
below). Regular scanning at 80 Mile Beach continues to reveal that there is more
movement between the 2 local sites then we realised and also there are some
excellent records of Red Knot that move from 80 Mile Beach to Roebuck Bay for a
month before heading to China.
SPECIES
GREAT KNOT
GREAT KNOT
GREAT KNOT
RED KNOT
RED KNOT
INDIVIDUAL
MARK
AX
EC
09
4YBBW
4YBBW
SEEN 80
MILE BEACH
10/11/2012
10/11/2012
10/11/2012
10/11/2012
11/11/2012
BANDED AT
YALU JIANG
YALU JIANG
CMDT
MANAWATU
MANAWATU
LIAN-YUNG
ESTUARY
BANDED
ON
30/03/2012
9/04/2012
11/04/2012
9/10/2010
9/10/2010
ADDITIONAL INFO
DID HAVE A RADIO TAG
RADIO TAG SEEN AT 80MB
GEOLOCATOR ON WHITE
LITTLE TERN
09
9/11/2012
13/07/2012 FLAG
GREATER SAND
PLOVER
V6
11/11/2012
TAIWAN
?
GREATER SAND
PLOVER
L4
11/11/2012
HONG KONG
?
Yalu Jiang is in far NE China on the China/North Korea border.
CMTD is Chongming Dongtan National Nature Reserve on Chongming Island in the Yangtze River Delta near
Shanghai.
Manawatu is near Auckland in New Zealand.
Lian-Yung Estuary is on the west coast of Taiwan.
Extra info from Professor Ma of Fudan University;
The GK with ELF 09 is really the bird we attached radio-tags this spring!
This bird was attached radio-tags at CMDT on 11 April, it left CMDT on 12 April, AND
THEN, it was detected again at YLJ on 18 April, and finally it left YLJ on 15th May. It's
great to find the bird again in the non-breeding grounds!
We also saw plenty of plain flagged birds from CMDT and singles from Hong Kong
and Sakhalin Island, Russia.
So a very successful trip.
Chris Hassell & Adrian Boyle