From Fish Owl to Gulls

 I visited Cheung Chau the other night and successfully found the Brown Fish Owl at its 'usual' spot along the promenade. As always, it was such a thrill to see this species in the wild, I can never get bored of them. Brown Fish Owl is a widespread species in Hong Kong, you can find them near many streams, as well as water catchments and reservoirs, or in this case the waterfront.

Brown Fish Owl

Many birds in Tai Po Kau are now showing signs of breeding, such as Grey-chinned Minivets which are now getting paired up instead of moving in large flocks. The usually quiet Plain Flowerpeckers are now very vocal and many can be heard throughout the trails.

Grey-chinned Minivet - male

Plain Flowerpecker

I heard the melodious songs of a White-rumped Shama, a species I seldom see at Tai Po Kau. It was behaving in the most classic 'Shama-like' manner, singing loudly in a gully inside the dense forest, it later showed itself briefly. Previously recognised as released or escapes, the number of Shamas reported in Hong Kong the last few years suggests they have now established a small breeding population.

White-rumped Shama

Speckled Piculets can be heard drumming, this one was pecking away near the top of a bare tree, which made it very visible. Another very vocal species at the moment is the Chinese Barbets, where this was a very rare species just a few years back, at least two were calling constantly at Tai Po Kau with several other reported at various sites such as Kadorie Farm, Shing Mun and Tai Lam, the pair at Tai Po Kau seems to be making a nest on a dead tree stump, a good sign that this species is slowly spreading.

Speckled Piculet

Chinese Barbet

A Ring-billed Gull was reported on Saturday at Mai Po, which will be the first ever record for Hong Kong as well as China, unfortunately I had work in the afternoon that day and missed the bird. I tried my luck the next day and ventured out to Deep Bay. The mudflat wasn't particularly interesting, the only notable wader being a Far Eastern Curlew. Many Black-faced Spoonbills now in their breeding plumage, making them even more attractive to look at. Caspian Terns are now in decent numbers.

Far Eastern Curlew

Black-faced Spoonbill

Caspian Tern

Despite not being able to relocate the Ring-billed Gull, there were plenty of other gulls to look at. Large Larus species have always been troublesome group of birds for birders worldwide, the inconsistencies of information of these gulls in Asia have made learning how to differentiate them even more challenging, as taxonomy is being updated every few years. The constant hybridisation of the three (or two) species that occurs in Hong Kong and the physical differences at various age makes identification even more difficult. None the less, gulls are fascinating and well worth spending some time to look into. I can't dare say I am a good 'gull-er', but it is important for birders to keep in mind that gull identification is a constant learning process.

Currently, IOC list that two members of the 'Herring-type' Larus that occurs in Hong Kong are the Vega Gull and Lesser Black-backed Gull. Of which, two subspecies of Vega Gulls are known to occur in Hong Kong, namely vegae vegae and vegae mongolicus. Of these two mongolicus is by far the more common one. Here is a brief update on the large gulls that occurs in Hong Kong.

Vega Gull (mongolicus)

Here is a good example of an adult Vega Gull mongolicus early in the year and in spring, with completely white head, pinkish legs and lighter grey backs. It is important to note that mongolicus moult earlier than the rest due to their breeding grounds being further south. 

Vega Gull (mongolicus) - adult

This below is likely a sub-adult bird showing most of the same features as adult, except for some feathers still retaining on lesser coverts, as well as fine spots on the back of the neck.

Vega Gull (mongolicus) - sub-adult

Likely a 3rd year bird, with very worned out tertiaries, greater and lesser coverts, with 'saddle' developing. Overall structure is that expected of mongolicus, shorter winged than heuglini.

Vega Gull (mongolicus) - 3rd year

Here are a 2nd year bird that shows traits of Vega vegae such as well marked head and neck, although not quite as extensively as one might expect, it is also not quite as blotchy as expected on the flanks or underside. Structurally this feels shorter winged than that of heuglini, so I am leaning towards this being either a vegae or mongolicus, but can't confidently identify these to species level.

2nd  year vegae / mongolicus?

Vega Gull (vegae)

This is the least common of the three 'common' species of large gulls in Hong Kong, adults seen in Hong Kong are usually easily picked up by heavily marked head and breast, as well as pink legs. This is an old photo from Feb 2016.

Vega Gull (vegae) - adult

The individual on the left here I would consider a good candidate as a 3rd year vegae, compared with the heuglini on the right, it looks much chunkier, where as heuglini looks slimmer and more slender. The heavily mottled neck, breast as well as underside is also a good indication for this being a likely vegae.

3rd year vegae (left) and 2nd year heuglini (right)

A very dark looking individual probably a 2nd year vegae, first of all it is very heavily blotched and well marked from head to underside, this is very unlikely to be heuglini or mongolicus. Also note the almost unicolour greater coverts and very thinly patterned scapulars and coverts, giving it an impression of 'light back'. 

Probably two mongolicus (left) and 2nd year vegae (right)

2nd year vegae

Lesser Black-backed Gull (heuglini)

By far our most numerous large gull, local birders usually just refer these as Heuglin's Gulls. adults are easily separable with Vega due to its very dark back, structurally they look more slender and longer winged, leg colour is also a good method to separate them as adult heuglini always have yellow legs. while 2nd and 3rd year birds show similar structure with adults, with darker scapulars and coverts than Vega in general, with a more distinct 'white collar' around the head.

Adult heuglini (left) and 2nd year heuglini (right)

These are the general rule of thumb for 'herring-type' large gulls in Hong Kong at the moment, there are of course a lot of variations and hybridisation are known to exist more often than we would like, therefore it is important to keep in mind that identifying these gulls are sometimes like looking at a spectrum, where you may get traits of both species in one bird, sometimes on more than the other.

Gulls, Gulls, Gulls...

Glaucous Gull - or at least it is to me

Deep Bay in winter is good for two kind of birds, gulls and ducks, scanning masses of them may cause serious headaches but you would often find one or two goodies within commoner species. One of those goodies was an American Wigeon which some other birders had found a few days ago, it stood out from the rest of the Eurasian Wigeons like a sore thumb.

American Wigeon - hello again!

Having seen the last American Wigeon, I turned my attention to the gulls on display. Black-headed Gulls were obviously the most numerous, a few of them came quite close to the bird hide. There was also a terribly oiled individual, not sure how long it will take for it to moult out of this mess...Most Saunders's Gulls had assumed breeding plumage, a few 2nd calendar year individuals showed well, much smaller than Black-headed Gulls, with short black bill and legs.

Black-headed Gull

Black-headed Gull - or should I say Black-bellied Gull?

Saunders's Gull - 2cy

I counted just two Black-tailed Gulls, an adult plus a 2nd calendar year bird. The adult was slightly oiled but not as bad as the Black-headed Gull. The 1st year bird was in pretty bad shape however, missing it's left leg entirely and have a bunch of nylon nets wrapped around it's bill...Not sure how long it can last like this.

Black-tailed Gull - adult with Black-headed Gull for size comparison

Black-tailed Gull - a poor one legged 1cy bird

A good numbers of large gulls were on display which provided hours of 'fun'. Three species are currently recognised on the Hong Kong bird list, these are the Heuglin's Gull (Larus heuglini), Mongolian Gull (Larus mongolicus) and Vega Gull (Larus vegae), the classification of these gulls are highly debated in the birding world, where as the placement of these gulls varies from different sources, making identification of these gulls even harder. I compiled some general identification features for these three (supposed) species of gulls below:

Heuglin's Gull

- Smallest of the three species
- Adults have darkest backs
- Legs yellowish to bright yellow in adults, pinkish in juveniles
- Bill often brighter yellow, short
- Wings longer with long primary projection from tip of tail
- Adults with pale iris

In general it is believed that Heuglin's Gulls are the most common species in Hong Kong, adults having darker mantles, smaller stature and yellowish legs. sub-adults should is equally dark backed but with heavier streaks on head, plus dark tip to bill. 2cy birds are not easy to identify with Vega Gulls of similar age, reason being 2cy birds have pinkish legs, however their rounded heads often provides a clue.

Heuglin's Gull - adult

Heuglin's Gull - sub-adult

Heuglin's Gull - 2cy

Mongolian Gull

- Largest of the three species

- Adults with lightest shade on back

- Head often looking longer with slanted foreheads

- Adults moults into breeding plumage earlier, head all white earlier on in the year

- juveniles have paler head and often white foreheads.

- Legs of all ages pinkish

- Darker iris

The second most common species in Hong Kong, adults are easy to pick out from the rest as they often moult into breeding plumage early, so their complete white heads are often easy to pick up. Individuals of all age should show paler heads even in 2cy birds when compared with the other two species. Foreheads often white with no streaking. Legs pinkish. Often described as a rather 'full chested' gull with larger bill and stronger build.

Mongolian Gull adult with Heuglin's Gull to the left

Mongolian Gull - adult with 3cy bird

Mongolian Gull - 3cy

Mongolian Gull - 2cy

Vega Gull

- Slightly larger than Heuglin's Gull, but smaller than Mongolian.
- Heavier built and more robust than Heuglin's
- Heavily streaked head in all ages except adult in breeding
- Mantle shade somewhat in-between Heuglin's and Mongolian.
- Legs pinkish to reddish
- Iris slightly darker in adult than Heuglin's

Supposedly the scarcest of the three species, although I have a feeling that juveniles are constantly being identified as other species or simply ignored. Adults have very smoky heads, often heavily streaked and blotched from crown to breast. I lack confidence to identify any juveniles to this species, I saw one likely 3cy bird that was much darker and heavily streaked both on head and breast, also quite a bulky looking bird which I feel points more towards Vega.

Vega Gull - adult (taken last year for comparison)

Vega Gull - adult

Vega Gull - likely 3cy bird with adult Mongolian Gull to the left

I have yet gain enough confidence to nail the id for each gull, that will likely take a much longer time to master...Spotting a gull out of the ordinary from the three species was however slightly easier. I noticed a large gull with fairly dark belly but pale wings amongst the flock, it's white primaries were especially apparent when it flapped it's wings! Pink legs, bi-coloured bill with pink base and pale primaries all points towards a 2cy Glaucous Gull. It was on the small side for a Glaucous, I received mixed comments about this bird's identity, while some suggested that this could be a hybrid Glaucous x Slaty-backed or something...Although for me this seems unlikely, seeing that most hybrid Glaucous Gulls often shows distinct abnormal features such as darker or monotoned bill and darkened primaries, which this bird showed none of those features. Personally I would happily accept this as a Glaucous Gull towards the smaller end of the species's spectrum, although if the true identity of this gull should not be considered a Glaucous Gull then I must say gulling is probably way too difficult for my liking...

Glaucous Gull - 2cy

Back to some birds with little doubt of it's identity, the Black-capped Kingfisher showed well next to the bird hide, a species with such irresistible colours!

Black-capped Kingfisher

A Black Kite also perched close to the bird hide briefly, which allowed some closeup shots to be taken. While a few Temmink's Stints ventured to the front of the hide as the tide came in.

Black Kite

Temmink's Stint

Eurasian Wigeons and Northern Shovelers were numerous, many of them came in very close to the front of the bird hide, so close even that I was able to see the lamellae lined along the Shoveler's bill, it acts like a sieves to filter out any crustaceans and plankton in the mud and water.

Eurasian Wigeon - drake (right) & female (left)

Northern Shoveler - drake & female

Black-faced Spoonbills are starting to moult into breeding plumage, this particular individual came right up to the bird hide to the point where I could hardly fit it all in frame! Shorebirds species had yet to pickup, I only counted a few species including this Whimbrel and Common Redshank at close quarters, we should be getting some more species in the coming months.

Black-faced Spoonbill - assuming breeding plumage

Whimbrel

Common Redshank

Back inside Mai Po I saw the Black-backed Swamphen yet again, although this time it was even further so I did not even bother with a photo. Though an adult Purple Heron which stood right out in the open was much worthier of a photo!

Purple Heron

Gulls identification is challenging indeed, but it is good exercise for the brain...if you can stay awake long enough....

Mongolian Gull - yawn