Identification of breeding grounds and annual routines of the newly discovered bohaii subspecies of Black-tailed Godwits

The Bohai Black-tailed Godwit (Limosa limosa bohaii) is a newly discovered subspecies in the East Asian-Australasian Flyway. Based on satellite tracking of 21 individuals that were tagged in northern Bohai Bay, China, from 2016 to 2018, we here describe the annual cycle of this subspecies. All the birds had Thailand as their southernmost ‘winter’ destination. The spring departure was in late March during northward migration, Bohai Bay was the first stopping site where they spent on average 39 days (± SD = 6 d), followed by Inner Mongolia and Jilin province (stopping for 8 d ± 1 d). The arrival of the breeding grounds in the Russian Far East was centred in late May. Two breeding sites were detected, with average locations 1100 km apart; the eastern site was beyond the known Asian breeding distribution of the Black-tailed Godwit. Southward migration started in late June, with the godwits tending to make longer stops at the same two main stopping sites used in the spring, i.e. Inner Mongolia and Jilin province (32 ± 5 d) and Bohai Bay (44 ± 8 d), with some individuals making a third stop in the middle-lower reaches of the Yangtze River in southern China (12 ± 4 d). By the end of September, most tracked individuals had arrived in Thailand. Compared with the previously known subspecies, bohaii godwits have strikingly different schedules of migration and moult, this study thus adding to the knowledge about intraspecific diversity of black-tailed godwits in the East Asian-Australian Flyway.