On this website in January this year you read about the marathon flight of the Bar-tailed Godwits (sub-species baueri). These birds fly direct from Alaska to Australia or New Zealand non-stop, a distance of 11,000 km, across the Pacific Ocean. Birds stayed on the wing for up to 9.5 days without a rest – surely the longest flight for a land bird. These birds are now on their way back to their breeding grounds using a different route, complete with new satellite transmitters.
Biologists from the USA and NZ recently satellite-tagged a number of Bar-tailed Godwits at their non-breeding grounds in New Zealand. As part of their research Bob Gill, US Geological Survey (USGS) and Nils Warnock of Point Reyes Bird Observatory (California, USA) were looking at movements of shorebirds around the Pacific Basin using the latest technology available. In February 2007 Bob, Nils, Dan Mulcahy (USGS vet) and Nils' son, Noah Warnock, joined Phil Battley (Auckland University) and Rob Schuckard (NZ Wader Study Group) and bird veterinary surgeon, Brett Gartrell from Massey University in the South Island of New Zealand, in a highly successful catching and satellite tagging program. NZ Wader Study Group and Ornithological Society of NZ volunteers also assisted in the program. After all this the waiting began – would the equipment work? When would the birds leave? Would they make stopovers between NZ and the Yellow Sea? But now the waiting is over – the birds have started to migrate!
At the time of writing, seven birds are in the air heading north, passing by northern Australia and Papua New Guinea. Anyone interested can learn more about the project at www.prbo.org/cms/index.php?mid=424. You can also track the birds’ progress at www.werc.usgs.gov/sattrack/shorebirds. In addition to individual maps, if you have Google Earth installed on your computer you can use that to take a more interactive look at the data.
We know that most of the godwits need to stop at the Yellow Sea region to gain enough weight to fly to their breeding grounds. They must also have enough reserves to establish nesting territories and lay eggs at a time when there is not much food to eat. How they get there from NZ, and how they behave when migrating from Asia to Alaska is unknown. Once the godwits are in Asia, do they ‘refuel’ at one site or move northwards stopping on their way? Hopefully all will be revealed shortly!
Most of the godwits have a large black leg flag with white letters and numbers (e.g. E5, Y7) on the left tibia, some of the birds also have coloured bands. If you find that one of these birds has landed at your local estuary, please tell us about it! We’d love to know anything you can tell us about the bird. You might notice a satellite antenna, which will protrude out behind the bird. Looking for these birds may seem impossible but with enough people looking it is possible to find them.
Enjoy viewing their progress on the internet, and good bird spotting in the field!