pisco-azul-siberiano vs red-flanked/qilian bluetail

The most reliable field mark to distinguish the Siberian Blue Robin from the Red-flanked Bluetail is the presence of a distinctive white supercilium in the Red-flanked Bluetail, absent in the Siberian Blue Robin. Both species exhibit blue plumage, but the Red-flanked Bluetail has a more pronounced orange flank patch.

Look for the white supercilium and orange flanks in the Red-flanked Bluetail. The Siberian Blue Robin lacks these features and has a more uniform blue appearance.

The Siberian Blue Robin has a more uniform blue plumage, while the Red-flanked Bluetail features a white supercilium and a notable orange flank patch.