lpaul

Geoff, I think some of the photos on OBI are incorrectly identfied.  I hate to say it, but these include photos from a certain John and Jemi Holmes!!

The id of the two is difficult because there is so much racial variation within the two species, so much in fact that it seems likely that they both represent more than one species.

I find a quick method to separate the two is the shape of the streaks below.  On Red-rumped thay are narrow and even in width, in Striated they are slightly thicker, but usually flare towrds the base of the streak.  However, I've not seen this published so I'm not too sure how reliable this is!

Paul

lpaul

I'm not sure where the rufous hind collar feature originates - but this also varies with subspecies in Red-rumped.  One of the features for identifying nominate daurica is that the hind collar is interupted with blue (Vaurie: Birds of the Palearctic Fauna).

Whilst it is of course possible that Striated Swallow could occur in HK, this is largely a resident species.  It is also worth noting that the Taiwan populations of Striated are somewhat problematic and that some authorities suggest that these are best placed within Red-rumped.