June 22, 2008
Report on the travels and status of NW Australian sat-tagged Bar-tailed Godwits
Please remember when reading the information below that this is not the 'final story', these are the initial findings and may change when the final analysis is done. We also 'join the dots' between each signal, however the birds are so skilled at navigating that this is most likely the route they travel.
Dear Godwit watchers
This is just a brief update and includes some bad news in regard to 2 of our birds.
In summary we have nine birds alive on the Siberian Breeding grounds. Three are still in Roebuck Bay and we have lost contact with one bird and 2 have died.
4 birds are heading to or have arrived at the New Siberian Islands (NSI) just as Pavel Tomkovich predicted.
Updates on each individual bird
A map illustrating the current postions of the NW Australian Bar-tailed Godwits. Image: © 2008 USGS. Press image for enlargement.
We have three birds H0, H2 and C0 still in Roebuck Bay. Adrian and I have seen H0 and C0 at roosts at the eastern end of the northern shores of Roebuck Bay. They are both in zero breeding plumage without even a trace on their upperparts so maybe they were only 3 years old when we implanted the transmitters and not yet ready to breed?
We lost contact with C4 as she was flying along the coast of China. We hope that it is a satellite transmitter issue and that we will get a record of her or see her back here in Roebuck Bay in September, but migration is likely to be the stage of these birds incredible life cycle when they are under most pressure and therefore when most mortality may occur.
C3 is at 142 54E but on June 9th she appears to have taken a 100km journey to the SE before returning to whence she had come from and then followed this up with another return trip to the SE, this time of 200km each way. She has only been in Siberia since May 29 so she should still be nesting and staying in close proximity to her nest?
C6 settled initially in a marshy area before moving to similar habitat but some 165 km north. She arrived on May 28. She has also been walkabout and on June 4 to 6 was 256km due south of her supposed breeding territory. It seems odd to me for the birds to be moving away from their breeding territory and hopefully it doesn't mean that their nest failed for some reason. She has since returned to her 'core area' and then left for the NSI.
C7 is the most westerly of our birds at 140 54E and she has been behaving in the same way as the previous two birds and between June 4 and 6 was 165km south of her marshy breeding area in some hilly country but has returned to her core area.
H3 was the first to leave Roebuck bay the first to arrive in the Yellow Sea the first to leave the Yellow Sea and first to arrive in Siberia. She has now moved 860 WNW and is on the NSI where Pavel Tomkovich suggested the birds may go to fatten up for their southward migration.
H7 had remained at her presumed breeding site since her arrival on May 30 but unfortunately she seems to have died around June 9 based on the readings from her temperature sensor.
H8 was only hours behind H3 and they did very similar journeys both taking a short break in the southern Yellow Sea just north of Shanghai before moving to Yalu Jiang in northern China on the border with North Korea. They then ended up within 60km of each other on the vast tundra breeding grounds. H8 seems to have left his territory a day before H3 and has moved 700km west. His last signal had him heading for the NSI from the Siberian mainland.
H9 was the bird that had the most easterly location in the Yellow Sea being our only adventurous soul to use North Korea for her staging area.
She spent a couple of days in one location before moving 35km south west of where she landed but after just 5 or 6 days here she flew 70km NNE and still not happy she went 20km SE and then back again 5 days later. She has now head towards the NSI and is 260km from her 'core area'.
A3 we got a fantastic track of A3 in to her Siberian breeding location as her transmitter was on as she arrived. She has settled on low mountain slopes and is sticking to a very small area suggesting she will remain and breed there. She may already be laying or incubating! This optimistic report has changed as she seems to have died or been killed on about June 9. Her temperature sensor indicates this was her fate.
A7 had landed some 480km south of most birds in very different looking terrain. She is in the Taiga belt and this is usually only a stopover site if it is a late spring which doesn't seem to the case this year so we are unsure why she has chosen this location. She moved 30km north on June 6 but only within the same habitat. I would think that she is not breeding.
H3 and H8 heading west on June 18th. Image: © 2008 USGS. Press image for enlargement.
A9 has been very good to us and timed her departure from the Yellow Sea and her arrival on to the breeding grounds when her transmitter was on. She has remained more settled than some birds but has been on short explorations of about 11km away from the core area she transmits from.
Many thanks to all involved with the project and particularly to Lee Tibbitts for all her regular updates summaries and Google Earth grabs.
Now we cross our fingers for the batteries to last as well as the ones in the NZ birds did last year and see if we can track the southward migration. Don't turn off yet folks!
Cheers
Chris
For those of you not yet following the tracks of the NZ and Broome birds I recommend you do! It is fascinating stuff (but I would say that wouldn't I?) To view the birds follow the information below.
The best way to follow the project is to visit the USGS site. Scroll down to the bottom of the page and there is a godwit icon: Click the godwit to download the kmz file/icon to your desktop. Click on the icon and this will open Google Earth, where you can view the globe with the travels of the godwits marked out on it.
You will need Google Earth installed on your computer. It is a free download which you can get here.