A Ruddy Long Way to Fly
Migrants MonitoredA technological breakthrough has enabled researchers from the Australasian Wader Studies Group - a special interest group of Birds Australia [BirdLife Partner] - to study the amazing migratory routes of Ruddy Turnstone Arenaria interpres.
Four birds fitted with ultra-light geolocators took just six days to fly from Australia to Taiwan before continuing on to northern Siberia. One bird then completed its return trip back to Australia via the Central Pacific - a total round-trip of 27,000 km! Ruddy Turnstone is a small, highly-migratory wading bird with a large global range. It breeds in northern latitudes in open tundra habitat often close to water. Outside the breeding season it is found along coastlines, particularly on rocky or stony shores. It is the only species of turnstone in much of its range and is often called Turnstone.
"We have been amazed at the feats of Bar-tailed Godwit tracked by satellite from Australia and New Zealand to their breeding grounds in the high Arctic and back", said Dr Clive Minton from the Australasian Wader Studies Group. "Unfortunately the size of the satellite transmitters, and the batteries required to power them, precluded their use on smaller shorebirds like Ruddy Turnstone".
The researchers therefore decided to use new 1 gram light-sensor geolocators - supplied by British Antarctic Survey in Cambridge, England - and fitted them to eight Ruddy Turnstone spending their non-breeding season in south-east Australia in April 2009. Four geolocators were eventually retrieved from birds between 20 October 2009 and 8 January 2010."All four birds flew 7,600 km non-stop to Taiwan in just over six days, with three apparently travelling together", said Dr Clive Minton. They then flew on to northern Siberia, following separate paths and stopping over at different sites. "By early August, two had moved to Korea and south-eastern Siberia, respectively, but another bird returned to Australia via the Central Pacific!"
The Pacific bird spent 26 July -15 October on the Aleutian Islands before flying 6,200 km across the Pacific in four days to Kiribati, and then it made another four-day, 5,000-km flight to eastern Australia. "Five days later it was back in south-east Australia having completed a 27,000-km round trip", added Ken Gosbell - Chairman of the Australasian Wader Studies Group.
On some of the longer flights it was possible for the team to calculate the flight speed achieved. For the flights from Australia to Taiwan and the flight back from the Kiribati to Australia the average speed was 50 to 55 km per hour. "A higher speed of 65 km per hour was achieved during the flight from Alaska to Kiribati, indicating possible assistance by tail winds", noted Ken Gosbell.
Spurred by these exciting results from the initial trials of geolocators a further 60 have been applied by researchers from the Australasian Wader Studies Group, the Victorian Wader Study Group and Deakin University. Geolocators have also been applied to 30 Greater Sand Plover Charadrius leschenaultii and four Sharp-tailed Sandpiper Calidris acuminata.
"The 2010–11 wader season will be eagerly anticipated as we retrieve these geolocators from returned waders”, said Professor Marcel Klaassen of Deakin University. “These data will elucidate the physiological and ecological constraints these birds are facing during migration, hopefully adding to the protection of the many Australasian migratory waders that are currently facing dramatic declines”.
4th July 2014