Tracking the Stejneger's stonechat Saxicola stejnegeri along the East Asian–Australian Flyway from Japan via China to southeast Asia

Abstract

The East Asian–Australian Flyway spans from north Asia to Australia and is the world's richest birds' flyway because it involves > 40% of global migratory bird species. However, information is lacking on individual migratory routes and non‐breeding grounds for small land birds using this flyway. Here, we present the first migration tracks of the songbird Stejneger's stonechat Saxicola stejnegeri from this part of the world using light‐level geolocators. This species depends on grasslands during the entire annual cycle and was captured and equipped with tracking devices in Hokkaido, northern Japan. All individuals traveled through southern Primorye or eastern Heilongjiang (Russia/China) before flying southward via central China toward their major non‐breeding grounds in southeast Asia (China, Laos, Cambodia, Thailand, and Vietnam). Individual stonechats spent 42–70 d en route during their autumn migration. Both the major non‐breeding grounds and the stopover sites are likely to pose challenges to the persistence of this species, because these habitats are currently degraded and will likely be lost in the near future due to intensified agriculture and the establishment of permanent croplands. Moreover, the areas used by Stejneger's stonechat during migration largely overlapped with illegal trapping areas in northeastern China.

Extreme genetic similarity does not predict non‐breeding distribution of two closely related warblers

“…, Yamaura et al. ), but failed to differentiate obvious migration movements from known stationary periods with our data.…”

“…Following the methods of Yamaura et al. (), we calculated the average solar zenith angle at twilight and a log‐normal density distribution of twilight errors during the calibration period. Because the solar angle recorded by geolocators has been found to vary among habitat types and between breeding and non‐breeding areas (Stutchbury , McKinnon et al.…”

“…Following the methods of Yamaura et al (2016), we calculated the average solar zenith angle at twilight and a log-normal density distribution of twilight errors during the calibration period. Because the solar angle recorded by geolocators has been found to vary among habitat types and between breeding and nonbreeding areas (Stutchbury 2013, McKinnon et al 2015, we compared our average calibration zenith angle to the angle recorded on five ML6040 geolocators placed on overwintering Golden-winged Warblers in Jinotega, Nicaragua, in January 2015.…”

Programmed and flexible: long‐term Zugunruhe data highlight the many axes of variation in avian migratory behaviour

“…Siberian birds had the longest Zugunruhe period in autumn and the shortest in spring. This extended autumn Zugunruhe period is likely related to the long distances travelled by this population, paired with a possibly slower pace of autumn migration (Yamaura et al 2016, but see Raess 2008). Alternatively, the long fall Zugunruhe may reflect a necessity to facultatively remain in migratory condition because of unpredictable resource availability (Helms 1963).…”

Flexible reaction norms to environmental variables along the migration route and the significance of stopover duration for total speed of migration in a songbird migrant

“…[74, 78]. First, daily sunrise and sunset times were identified using the arbitrary light intensity of “1.35” for the BAS and Biotrack geolocators and 1.35 lux for the Intigeos, similar as in other studies [74, 78, 79] (Additional file 1).…”