Friday, 20 November 2020

Second Chances - Chinese Leaf Warbler

Birders doesn't always get second chances for twitches, sometime you fail to connect with a bird and thats it. I failed my first attempt on the Chinese Leaf Warbler found by Roman Lo at Tai Po Kau earlier, it was showing 45 minutes before I arrived and didn't show the entire afternoon! I thought the bird had moved on and gave up, only to be informed the next morning that it was back at the same location! I quickly got ready and headed to Tai Po Kau before work. Luckily, this time the warbler showed beautifully for the entire 30 minutes I was there.

Chinese Leaf Warlber

It was feeding on a piece of bamboo infested with scale insects, actively foraging around it and picking them off like popcorns! There had only been a handful of records in Hong Kong, and not all previous records claimed were accepted. This is a tricky bird to identify, as it superficially look similar to Pallas's Leaf Warbler.

Chinese Leaf Warlber - feeding frenzy on scale insects

How do we know this is a Chinese Leaf Warbler for sure you may ask? Firstly, this individual was pretty vocal and often made a sunbird like call that most birders may simply ignore! Although the call was slightly more rhythmic and more powerful when you really starts comparing the two. Secondly, the crown stripe was what I felt really different from Pallas's Leaf Warbler, especially closer to the forehead, where the crown stripe fades and does not touch the bill. The overall colour is also more subdued, while in Pallas's you expect the bird to be much brighter. Structurally, Chinese Leaf Warblers are longer than Pallas's, somewhat closer to what you expect on a Yellow-browed Warbler. Overall, a very nice bird to see, and likely one which have been overlooked in the past!

Chinese Leaf Warbler - subdued colours and less contrasting crown stripe

Also present was a single Crested Serpent Eagle which perched on its 'usual' spot, calling away loudly. While it may not be there all the time, I have seen it perched there fairly often, no doubt a very good tree to look out for this handsome raptor! 

Crested Serpent Eagle

Over at Mai Po, a Canvasback was reported on the 16th. It caused a huge amount of excitement, as this would have been a Hong Kong 1st! Although all we had was a very blurry photo to go by, and after many photos coming through which simply doesn't show the right bird, it looks as if the initial bird had either moved on or it was misidentified, I certainly hope it was the former, but I will leave the decision to our record committee! Nonetheless, there are plenty of 'interesting' ducks to see, I tried my luck on the 19th and connected with the small flock of Mallards; a species we don't see often enough in Hong Kong!

Mallard - not a common sight in Hong Kong

Also present was the largest single flock of Eastern Spot-billed Duck I have seen on a single pond, while we often see this species in singles or pairs. They are very handsome ducks and one we too often neglect.

Eastern Spot-billed Duck

I located some fairly good looking Common Pochard which provided for a wonderful photographic opportunity. They were actively diving and feeding along the edge of pond 11, the males showed beautifully in the morning sun, the females were equally photogenic. Common Pochard is not really a common species in Hong Kong, in some years we barely get any records, so seeing small flocks of these was quite nice.

Common Pochard - male

Common Pochard - female

There were plenty of Tufted Ducks, a good time to scan for any other diving ducks. One bird i noticed with greenish sheen and a rounded head that looked quite bulbous. I thought could have been a good candidate for Greater Scaup, but it lacked any vermiculation on the back which I would expect to see even in a moulting male, so perhaps its just a tufted male without a crest?

Tufted Duck

Greater Scaup or Tufted Duck?

Another problematic individual appeared, it had a white patch on the lore, not very large but slightly bulkier than most Tufted females present. It looked slightly bigger with a rounded bulbous head, bill also looked slightly larger. It also showed a pale patch on the cheek, which is one of the main differences between Tufted and Scaups. The bird swam closer in the end and allowed for some closer photos to be taken, it wasn't until it was very close that I noticed some faint vermiculation on the mantle. For me, it ticked all the right boxes for a 1st winter Greater Scaup.

Greater Scaup - 1st winter

However, after further enquiries, the opinion on the identity to this bird was split between Tufted and Greater Scaup amongst birders. The reason being one of the photo showed a posture which reminiscence of female Tufted, especially a photo of which I took right after it dived; the neck and head shrunk. For comparison, here is a photo of a Tufted female present at the time and the bird in question below. Part of the white patch on the lore was also obscured by the mud, which made the patch looked smaller than it is. It just shows how tricky these two species can be in certain shape of head can change after diving and there are some overlapping in sizes. However, I think with the combination of various features all checked out (Larger head, pale spot on cheek, vermiculation on back), I am quite confident to call this a 1st winter Greater Scaup.

Tufted Duck - female

Greater Scaup - 1st winter

Other than diving ducks, there were plenty of dabbling ducks to look at, including hundreds of Eurasian Wigeons, Northern Shovelers, Northern Pintails and Garganey...

Eurasian Wigeon

Northern Shoveler

I also caught up with the pair of Greater White-fronted Geese, they were showing at close range, although slightly obscured by tall grass, I enjoyed good views of the pair feeding. Also present along the same patch was a very nice looking Intermediate Egret.

Greater White-fronted Goose

Intermediate Egret

Other birds seen around Mai Po includes a Manchurian Bush Warbler which showed briefly. A flock of at least 20 Chinese Grosbeak was a first for me this winter, both males and females showed very well, they are certainly a nice reminder that winter is upon us, despite the fact that it was still 30 °C outside...

Manchurian Bush Warbler

Chinese Grosbeak - female & male

Last but not least, a lovely Common Kingfisher which posed nicely for a photo, despite how common they are I still stop to enjoy their vivid colours every once in a while.

Common Kingfisher

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