As the heat continues, our slow days continue. Nevertheless, we are up and out before the sun rose over the mountains once again to see what the day will bring!

First up was one of our most frequently caught species: the Huet’s Fulvetta! This individual was young bird, with a juvenile-type iris and all juvenile tail. This bird was carrying out a complete postjuvenile moult, with just some inner old, juvenile Greater Coverts and outer juvenile Primary Coverts left. These juvenile feathers are far more loose and more dull grey-brown tone to them, compared to the better quality, more olive-brown postjuvenile feathers that are growing in. Note that there are also moult limits in the Primaries and Secondaries, but they are harder to differentiate from the moulted postjuvenile feathers. This is because the old juvenile feathers are still quite intact, as they are probably not more than a month old.

Next up was a gorgeous Mountain Bulbul! This individual was originally ringed in June 2021, as a 2nd calendar year bird or older. This means it is now at least 4 years old! This bird can also be aged by the iris colour (comparison between adult and juvenile below). This bird also seemed to be undertaking a Complete Summer moult, with moult limits present in the Primaries, Primary Coverts and Secondaries.

Finally, we ended with two of another beautiful resident: the Streak-breasted Scimitar Babbler! These were both juvenile birds in active Complete moults. As with the other species in this post, we can age the birds based on the retained juvenile coverts, which again are of a worse quality and with a more chestnut brown ground colour.

A quick reminder on using irises for ageing. Below are the three species seen here, with adults on the left, and juveniles on the right. In general, adult irises are darker and have more of a blood-red tone to them vs the juveniles which are more grey- or chestnut-brown.

However, as has been mentioned previously, we need to be careful with ageing from irises. Firstly, we cannot be sure with all species when juveniles develop adult-type irises, which can lead to confusion. Furthermore, there will always be some intermediate individuals that show a mix between two, for which it is best to look at other characteristics for ageing.

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.*