September 8, 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 another brief update as things are getting very interesting and exciting as our birds arrive back in the bay on the final southward leg of their migration.
Updates on each individual bird
This is another brief update as things are getting very interesting and exciting as our birds arrive back in the bay on the final southward leg of their migration.
All times have been worked out to WA time.
A9 seems to be taking a break in her journey on the coast in the far SW of Sulawesi.
C2 appears to have taken a break in her journey on Flores after a previous break in the Philippines. She now appears to be on her final leg to Roebuck Bay. I need to check this with Lee. The following bird's reports are much clearer on what they have been doing. None of C2's signals are very accurate currently.
C3 arrived back in Roebuck Bay at approximately 8PM on 30 August assuming her speed was 50km/hr over the final 580km of her journey. I saw her at 'The Boiler' at 3PM on Saturday 6 September in the same flock as H9. It was fortunate sighting as the flock was disturbed just after I saw her aerial, but not her flag. However the birds settled again in a very tight flock but I persevered and saw an aerial again but I could only see a fraction of the top of the flag and no engraving on it. However luck was with me and the flag moved round to reveal C3. I could only see a fraction of the bird herself but the flag was in full view. She was transmitting when I saw her and her location had her 2.5km from where I saw her. It was not a very accurate signal but also I had birds come in to the roost from over the mangroves and it is perfectly feasible that she was roosting out there on damp mud from the previous days high tide and then came to the beach as the tide receeded and that is when I saw her. She was only 1km from her capture site. Clare and Grant saw her again yesterday in the same flock as C7 and very close to the flock in which Andrea found C6. Her first re-sighting was 1km from her capture site
C6 arrived back in Roebuck Bay at approximately 530PM on 6 September assuming her speed was 50km/hr over the final 344km of her journey. She was found at a roost by Andrea Spencer at 230PM on Sunday 7 September within 200m of C7 and C3 on the same day and H9 and C3 from the previous day. Her first re-sighting was 1km from her capture site
C7 arrived back in Roebuck Bay at approximately 6PM on 2 September assuming her speed was 50km/hr over the final 614km of her journey. And she was seen by Grant and Clare Morton in a flock of some 13,000 knot and godwit very close to 'The Boiler' roost site. Andrea and I were scanning a smaller flock of about 1000 birds (see report on C6) but within 200m of Grant and Clare. When I went to check Google Earth for this write-up it seems that while Clare and Grant were watching C7 her transmitter was sending a signal to the satellite! The time and place match up exactly! Her first re-sighting was 1km from her capture site.
C7's roosting location in front of Grant and Clare! Image: © 2008 Google Earth. Press image for enlargement.
H3 landed back in the bay at 230PM on 2 September, assuming her speed was 50km/hr over the final 470km of her journey. Her transmitter was not on during that final 470km of her journey. She has not been seen since she arrived back but her transmitter is still working and she last reported at midnight on Saturday 6 September. She seemed to be out on the salt marsh north of Crab Creek, this location would match perfectly with what we know of night time roosting habits from previous radio tracking work.
H8 our only male with a transmitter is still at Yalu Jiang and has not started his final southward journey to Roebuck Bay yet. His transmitter is still working and he reported in at 10PM on Saturday 6 September.
H9 probably arrived in the bay at about 7AM on Saturday 6 September and a mere 8 hours later I saw her at 'The Boiler' roost site, 7km east of her capture site at 'Two Dog Hermit'. She looked skinny but well and was preening vigorously and then she had a sleep, (understandably!). Her transmitter is still working and she reported from the mudflats south of Crab Creek at 5PM yesterday Sunday 7 September.
H9 taking a well-earned nap. Image: © 2008 Adrian Boyle. Press image for enlargement.
This is a remarkable set of sightings when I consider that of the 3 birds that never left the bay there have only been 2 sightings of C0, 5 (2 on the same day at different roosts) of H0 and zero sightings of H2 during the entire winter period.
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 right back to the northern shores of Roebuck Bay where the birds were first caught and implanted with the trackers. Don't turn off yet folks!
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. To view the birds follow the information below. When you click on the icon with a number you will be given a list of information. Note that the date is month/day/year and the time is UTC/Greenwich meantime, add 7 hours for WA and Chinese time. Korea is another one hour ahead.
You will need Google Earth installed on your computer. It is a free download which you can get here.