It might be an idea to consult David James on this - you can contact him at [email protected]
. He was very helpful indeed with my own chance sighting of CIF in Malaysia.
I thought it might be rare in Taiwan but I didn't know it would be that
rare. However, your images are of a very high quality and clearly show the diagnostic breast tabs.
I wonder if this has anything to do with Cyclone Amphan. There have been numerous sightings of pelagic species quite far inland in West Bengal over the last few days - groups of Short-tailed Shearwaters flying up the Hooghly, for example. Our own Seth Miller reported a Wedge-tailed Shearwater in Dhaka!