Another warm morning dawned quiet, and we worried we may not be able to see many birds today, but thankfully they showed up with a wonderful array of species over the two days!

First up was this beautiful pair of Velvet-fronted Nuthatches! Though we are able to sex this species, based on the patterning of the face, we unfortunately do not know too much about the moult strategy of this species (similar to a lot of our other secretive residents). In the top individual above, we can see a more diffused black eyebrow, and only a small, rounded black area above the bill. This tells us this is a female. Her wing consists of all uniform feathers. This could suggest an adult, if we assume juveniles carry out a summer partial moult (like most other nuthatch species). However, as we are not certain of this, it is best to leave them as unaged, or ‘1st calendar year or older’.

The male, below, shows a much more broad and conspicuous black eyebrow and a larger, more angular black area above the bill. Interestingly, his wing does show a moult limit, with growing primaries, and 2 obviously unmoulted innermost secondaries (being brown, bleached and worn). What does this mean? Well, we will need to catch more to work this out- typically we only catch 1 or 2 a year!

Continuing with the hard-to-age species, next up was a gorgeous Amur Paradise Flycatcher! This is one of our more common autumn migrants, along with the similar looking Japanese Paradise Flycatcher. An interesting fact about both these species is that males have extraordinarily long tail feathers in breeding plumage- Amur’s tail feathers can be twice the length of their body!

However, as these species are most commonly seen in Hong Kong in Autumn, we usually catch individuals in non-breeding plumage, where males and females cannot be distinguished. So, our first job is to separate Amur from Japanese Paradise Flycatchers. We can do this by looking at the contrast between their glossy crown and grey chest, which is much less pronounced in Japanese. Furthermore, the grey chest slowly diffuses into a white belly, versus the Japanese which has a sharper limit between the grey and white (see individual below).

It is thought that both these species may have Summer Complete moults in both adults and juveniles, but more research is needed. For now, we leave these birds as 1st calendar years or older!

To another Flycatcher, but this time, one that breeds right here in Hong Kong- the beautiful Hainan Blue Flycatcher! It is common for us to catch the young birds at this time of year, but it is not common for us to come across such a beautiful adult male! These guys follow the very typical moult of adults Summer Complete, juveniles Summer partial, and we can see in this bird all feathers in the wing and tail are of nice, adult quality with their gorgeous blue hue. Therefore, we can say he is in his 2nd calendar year or older!

Our session this month ended with quite a surprise- a Brown-chested Jungle Flycatcher! These birds are not common for us to catch, and have been declining in the few years, with just 3 caught since 2017. They are listed as vulnerable on the IUCN RedList, with a suspected decline in populations across their distribution. So, it certainly is a privilege to see them up close. In this individual, we can see a uniform wing and tail, suggesting this is an adult bird. We can discern this from previous captures (see 22/09/2022 post), which show clear moult limits in the GCs between juvenile and postjuvenile feathers. Therefore, the moult strategy of the Brown-chested Jungle Flycatcher must be adults Summer Complete, juveniles summer partials (as most Flycatchers).

A wonderful day!

Daily Totals

*Please note that all wild birds, their nests, and eggs are highly protected (under Wild Animals Protection Ordinate, Cap. 170) in Hong Kong. It is an offence to willfully disturb, take, remove, or injure wild birds or their nests/eggs. The actions described here were undertaken by trained professionals holding the necessary licenses and permits issued by the AFCD.*