lrichard

You say there are 3-4 of them. Do they sound like Fork-tailed Sunbirds? Are there males around?

I'm asking because the habitat (mangroves) is odd, the bird in the photo is quite yellow below, and its primary projection is rather short.

The obvious possibility is Olive-backed Sunbird, but hey it's a hot summer and I'm bored and wishful.

lrichard

Thanks lukying, Dylam, Dave and Cherry

Yes, the YSO bird must be a juvenile Fork-tailed Sunbird. It looks very similar to the one photographed by Cherry.

I think Olive-backed Sunbird is one to look out for in Hong Kong. It occurs in Hainan and along the coast of Guangxi and southwest Guangdong as far as Xitou (less than 300 km W of HK), where Jonathan Martinez has seen up to four on several dates in late autumn and winter.