The presence of juvenile Dark-sided Flycatcher in HK causes some confusion when separating Grey-streaked to Dark-sided. In HK, juvenile Grey-streaked Flycatchers are rare, and they are more well grown when they arrive at HK. In Comparison, juvenile Dark-sided Flycatchers are very common. They have white spots all over the upperparts, and with streaks on the breast similar to that of Grey-streaked Flycatcher. So if you see clear spots all over the upperparts, that is almost certainly Juvenile Dark-sided flycatcher.
HF Cheung
