Transmitter reveals new Spoon-billed Sandpiper breeding grounds

The world's smallest transmitter has helped discover a previously unknown breeding ground of the Critically Endangered Spoon-billed Sandpiper.

Thanks to the installation of a tiny solar satellite transmitter, a Spoon-billed Sandpiper was tracked in spring 2024 between Thailand and the Siberian oblast of Chukotka, where it finally stopped in an arid valley – a site not known as a breeding ground for the species and, unusually, not consisting of typical nesting habitat.

Spoon-billed Sandpiper is Critically Endangered, with a current population estimated at fewer than 500 adults. It is threatened by the destruction of its migration and wintering areas and by illegal hunting, as well as climate change. However, its decline appears to be slowing, thanks to conservation measures taken at international level, including a captive-breeding programme and monitoring individuals via transmitters.

Spoon-billed Sandpiper breeds in North-East Siberia. It is one of the world's rarest birds (Jens Kirkeby).

Tiny transmitter

This year, as reported by Ornithomedia, the world's smallest solar satellite transmitter, weighing a mere 1.2 g and costing nearly $5,000, was developed by the Californian company Microwave Telemetry. It is light enough to be placed on the back of a Spoon-billed Sandpiper without the need for a harness, ensuring its natural detachment when the bird moults.

Since 2016, several transmitters have been placed on a dozen wintering sandpipers in South and South-East Asia, making it possible to identify new important sites on their migratory route to Siberian nesting sites. These breeding grounds are still poorly known due to the great extent and remoteness of the area.

On 4 April 2024, a tagged Spoon-billed Sandpiper, known as 'K9', left Thailand, where it spent the winter.

Epic migration

The bird first undertook a four-day flight, covering 1,600 km, before making a stop-over in Guangdong Province, China. It then flew 500 km to Fujian Province. Both of these sites were previously unknown stop-overs for the species. 

A week later, K9 continued north to Jiangsu Province, a flight of 1,000 km. By 25 April, it had travelled a total of 3,100 km, reaching the southern coast of the Yellow Sea, but was still only halfway through his migratory journey. 

An 800-km flight took the sandpiper to North Korea over the Yellow Sea, then more than 2,000 km to the Russian island of Sakhalin, before another 2,000 km to the border between the Kamchatka and Chukotka oblasts.

New breeding site

On 4 June, after a journey of nearly 8,000 km, K9 finally reached an unexpected destination: a barren river valley, which was a previously unknown nesting site. To protect the species from egg collectors, the exact location has been kept secret.

The chosen habitat was a surprise as it was not a sandy or gravelly coastal area dotted with crowberry bushes, which is typically favoured by Spoon-billed Sandpiper.

An in-depth article on the latest situation with Spoon-billed Sandpiper conservation can be read in the August 2024 issue of Birdwatch magazine.