Migration and wintering of Chestnut-cheeked Starlings Agropsar philippensis

Abstract

Chestnut-cheeked Starlings are summer visitors that breed in central and northern Japan and then pass the winter in Southeast Asia. Their breeding ecology has been intensively studied, and the effect of climate change on the breeding season has been shown. However, it is not yet known to what extent stopover and wintering conditions influence the advance of their breeding season because the migration areas and migration timing are not well known. In order to obtain such basic migration information, we attached light-level geolocators to Chestnut-cheeked Starlings breeding in Niigata, central Japan. The starlings started their autumn migration in September and after staying in Kyushu for eight days or more, they migrated through the Nansei Islands to the Sakishima Islands, then Taiwan, or Fujian (China) in a relatively short period of time. They arrived on their wintering grounds by late October. Their migration period averaged 33.9±8.3 days. Seven (44%) out of the 16 individuals that we tracked wintered in the central and southern Philippines and nine (56%) on Borneo. They remained in their wintering areas for an average of 166.3±5.9 days before commencing spring migration during late March. After staying for a period of time on Luzon Island in the Philippines and then traveling northwards through the Nansei Islands of Japan, they headed for their breeding grounds in Niigata arriving back there between 10-26 April, after an average of 27.0±5.6 days.