sgeoff

I find these immature birds a bit confusing, especially as the adult tail features are not yet apparent when the feathers are growing.  I assume these two, sitting atop a Causarina on the cable road on Lamma yesterday (Sept 3rd) are immature black drongos, taking into account a combination of body features, behaviour and calls, but can anyone give me a definitive ID and provide a robust diagnostic for the immatures of black and hair-crested?

wgeoff

This is a good question Geoff, these birds are causing me no end of confusion on Po Toi. Also the adults are moulting their tail feathers.

At the risk of the blind leading the blind, there are two points on your birds suggesting Black Drongo.

Firstly, both show a small white 'loral' spot just below the eye, which I think is diagnostic for Black Drongo when it is present but not all Black Drongos seem to have it.

Secondly, the beaks seem too small and not down-curved enough for Hair-crested. Compare this photo of a bird I think is a Hair-crested taken last week.



Other than that, I am treating all these odd tailed birds as Black Drongo unless they are obviously not.

kmike

I agree with Geoff W on both counts

Cheers
Mike

ajohn

The moulting drongos with odd tails that I see tend to be Black. Presumably Hair-crested go through a similar moult on breeding grounds but aren't as obvious (or maybe the tail shape is not as obvious).

Geoff S's photos definitely look like Black Drongo to me

sgeoff

Thanks for the comments.  I had never noticed that white spot before, and it has proved to be very useful, even if somewhat hard to see in the field.  There have been some great collections of black drongos on the wires in recent days (perhaps getting ready to take off?) with a variety of interesting tail styles.