This morning began as usual, warm and humid making our shirts stick to our backs as we set up the nets, even before the sun had risen in the sky.

But our efforts paid off with a gorgeous adult Red-throated Flycatcher! It’s not super often we catch this migrant, so it’s always a treat to have them! This species, like most flycatchers, carry out a Summer Complete moult in adults and a summer partial moult for juveniles. In 1st calendar year birds we usually find moult limits in the Greater Coverts. Juvenile Greater Coverts usually show whitish tips, not present on adult-type coverts. Above, we can see that our bird showed nice, fresh feathers in the wing and tail, with no moult limits. Thus, we can conclude that this is an adult (2nd calendar year or older) bird!

Next up was one incredibly feisty Brown Shrike! Brown Shrikes, like a lot of other Shrike species, retain their juvenile plumage for an abnormally long time- even up to two years! This makes it easy for us to age them, thanks to the scaley overall appearance. In the wing, we can see all ten Greater Coverts are still juvenile, with broad, pale fringes to the feathers.

The morning wore on and continued to be a busy day with a group of young bulbuls!

First up was a young Chinese Bulbul! These can be differentiated from the young Red-whiskered Bulbuls by the greenish colour to the back (instead of greyish brown), the different patterns of black and white in the face, the lack of black crest that the Red-whiskereds have, and the lack of red in the face and undertail. Both of these species carry out Summer Complete moults in adults and juveniles, making them inseparable by plumage upon completion.

However, these two individuals have not yet completed this moult, with both showing some moulted head and body feathers, and completely juvenile wings. Juvenile feathers can be differentiated by their looser density, and worse overall wear.

Next up was nothing short of a stunner in the nets- an adult White-throated Kingfisher! These are one of our more beautiful resident Kingfishers (although they are all beautiful!). The moult of Kingfishers is not very well studied, but this bird happened to be a recapture from September 2019! Therefore, we know that this is an adult bird, and is at least 5 years old!! In the wing, we can see a moult limit in the secondaries, and another in the primaries. A great addition to our studies!

Rounding off a fantastic morning, we ended with a gorgeous adult female Yellow Bittern! Females show a similar streaky wing to juveniles, but with a darker crown. With this, we can differentiate them from males, which show much more uniformally sandy colour across their backs. A wonderful morning!

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 wilfully 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.*