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We used satellite telemetry to follow the migrations of two populations of Bar-tailed Godwits, a group of 9 from New Zealand (NZ) and a group of 15 from Western Australia (WA). The birds from WA represent a subspecies that nests in eastern Siberia whereas the New Zealand birds nest in Alaska. We will compare the migration strategies of the two populations.
The northward flight of Bar-tailed Godwits began in mid-March with the departure of four satellite-tagged godwits from the North Island of New Zealand; they were followed in mid-April with the departure of 12 birds from Roebuck Bay. All birds flew nonstop to stopover sites along the coast of the Yellow Sea in China, North Korea, and South Korea. After about 6 weeks, birds flew nonstop to their breeding areas in west and north Alaska and north and central Siberia. In late June, the WA birds left breeding areas and flew north to staging areas on the North Siberian Islands. The two birds that we tracked to Alaska moved to the southwestern coast of the Yukon-Kuskokwim Delta in early to mid July and staged there until their transmitters lost battery power and went off the air a couple of weeks later (so we were not able to track their migration back to New Zealand). In mid to late July, all WA birds returned to the Yellow Sea region, most birds even returned to the same stopover site they had used during northbound migration.
In late August, the first WA bird took off from China on her way back to her southern home. She was followed over the next 3 weeks by the rest of the WA birds whose transmitters were still on the air (see image above). On ~ 8 Oct we tracked the last godwit back to Roebuck Bay; H8 had stopped off for a couple of weeks in Indonesia before making the final leg of his flight back to near where we tagged him over 8 months ago. Recently, observers in Firth of Thames and Roebuck Bay have resighted several of the tagged birds!
By clicking on the Update page you will see the progress of godwits from both New Zealand and Western Australia and by clicking on the Maps page you can select individual godwits and view their routes (we’ll update these soon now that the birds have settled down a bit). Thanks for your interest.
Synopsis of the 2007 effort
“Beyond all expectations” would not overstate the information obtained from the 16 godwits that were satellite-tagging in New Zealand in February 2007. In brief, this would include: 1) godwits from both North and South islands flying directly and non-stop to the Yellow Sea, 2) the North Yellow Sea and particularly the area around the Yalu Jiang Nature Reserve being a critical staging place, 3) birds also having non-stop flights from the Yellow Sea to the breeding grounds in Alaska, 4) the Kuskokwim Shoals off the mouth of the Kuskokwim River again proving to be the single most important autumn staging site for godwits in Alaska, 5) the third and final leg of the annual flight, that from Alaska to the nonbreeding grounds, being direct across the central Pacific Ocean, and 6) what would become the media darling, godwit ‘E7’ (see below), being tracked over her complete flight after leaving New Zealand in mid-March to her return in early September, an odyssey that covered almost 30,000 kilometers. Even the one bird (Y3) that did not migrate from New Zealand still provided a wealth of information on her use of the Farewell Spit area during the six-months her satellite-tagged mates were away from the area. |
