Last Migration: The Story of the Red Knot
Article | Updated 6 months ago
On 4 March 2015, Grant Lodge found a recently dead shorebird on a beach near Broome. The bird had a number of coloured leg flags and bands, which identified the bird as being part of a scientific data collection system. Mr Lodge preserved the specimen and contacted Ron Johnstone, the Curator of Ornithology at the Western Australia Museum. On its arrival at the museum, the specimen was prepared into a research study skin (registered number A39016) and was identified as a Red Knot (Calidris canutus piersmai).
Shorebirds are among the elite when it comes to long distant flights, moving from the high latitudes of the Arctic tundra in the northern hemisphere towards Australia to escape the harsh winters of the north. The Red Knot is one of the most colourful shorebirds and migrates the furthest distance, choosing the 15,000km flight to Australia and New Zealand.
Most migrants arrive in Australia during August or September and return back to their breeding grounds in April. Adult shorebirds leave without their newly hatched juveniles, who must find their own way south during the migration period. The Red Knot prefers to inhabit the intertidal mudflats of the Eighty Mile Beach in Western Australia and the shores of the Yellow Sea region in China and Korea when not inhabiting the breeding grounds in northern Siberia.
This particular specimen is female with a high amount of body fat, which suggests she was preparing for the journey north. Body fat is the fuel shorebirds burn during this non-stop migration. This species has the ability to build up to 30% of its body weight in extra fat stores over the span of a few short weeks, feeding off small marine worms, bivalves, gastropods and crustaceans.
Details of the coloured bands and flags on this specimen’s legs were sent to the Australian Bird and Bat Banding office in Canberra, which unearthed the history of its travels in the last five years. Banding, flagging and geolocation programs highlight the global flight paths that are of significance to the shorebird species. This Red Knot was first fitted with a band on 1 August 2010 at Eagles Roost, Roebuck Bay, Broome.
Through the following months it was spotted again at Roebuck Bay but by 30 May 2011 it was observed at Nan Pu, Bohai Bay, China and had returned to Roebuck Bay by the 3 September 2011 (a round trip of over 12,000km!). In the following years it was spotted more that 60 times in north Western Australia and on six occasions in China, always in May when it stopped to refuel before the second leg of its journey north.
Specimens like this female Red Knot provide researchers with a wealth of information on the migration and movements of a species alongside age, plumage and sub-specific identity. Shorebirds are a declining species worldwide and their habitats are under threat from industrial development and global climate change. Understanding the habitats and habits of the Red Knot can help researchers approach the topic of conservation and the Global Flyway Network program.
For more information about the Red Knot, please see this article by WA Museum Ornithology Curator Ron Johnstone.