Tuesday 27 February 2018

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


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

Thursday 15 February 2018

Warming Up

White's Thrush - a classic winter species in Hong Kong

Chinese New Year is just around the corner and the weather had been gradually warming up again. It's quite a stark difference when you compare to the coldest days, where you won't see so much as a single insect, now bees are buzzing around the flowering trees and even the odd butterfly had emerged. I even encountered a singing Rufous-tailed Robin, certainly triggered by the warmer weather, getting itself ready for breeding.

Rufous-tailed Robin

Reptiles are making use of this warmer weather to bask in the sun, however making them easy prey for Crested Serpent Eagle, I saw this one at Lok Ma Chau, chowing down what looks like a Checkered Keelback. I do sometimes wonder whether the Crested Serpent Eagles goes hungry during winter months, when the snakes are not so active? Do they resolve to hunting other prey items? I don't have the answer to that but this one certainly seemed to enjoyed it's big lunch before it took to the air again.

Crested Serpent Eagle - looks like it had a decent meal!

At Mai Po, Black-faced Spoonbills numbers are still good, you will easily encounter flocks dotted around the reserve. Great Cormorants are still abundant, although we will start to see a drop in their numbers from March to April onwards. Northern Shovelers seems to be the most abundant dabbling duck species in Mai Po, here's one taking a bath.

Black-faced Spoonbill

Great Cormorant

Northern Shoveler

I finally managed to caught up with the long staying Smew, this female had been showing well around pond 6, although on the day I visited it was with a flock of Tufted Ducks at pond 3. It swam quite close to the bird hide for a good look, the best views I've had of a Smew in Hong Kong! Although a vagrant, Smew seems to have became much more regular at Mai Po in recent years.

Smew - female

At Tai Tong, I caught up with a few wintering Thrushes, these were much more photogenic and regularly fed on the ground, with a few even allowing fairly close views. The most dominant species were Grey-backed Thrush, I counted at least five or six individuals, here a photo of the male and female.

Grey-backed Thrush - male & female

A single Pale Thrush was also present, although much shyer than the Grey-backs, this male still showed fairly well and I managed a half decent photo of this handsome Thrush. A fairly photogenic Eyebrowed Thrush also made an appearance, for a species that is usually very shy this bird was the most obliging I have seen.

Pale Thrush - male

Eyebrowed Thrush - 1st winter

A pair of White's Thrush was probably the star bird there, the first individual had a weird looking face and had no eye-rings of any sort, just looking overall very scruffy. The second bird was much brighter and overall cleaner. The taxon of the Scaly Thrush (Z. dauma) complex had been in flux for years, although White's Thrush (Z. aurea) is now considered a full species on it's own, the actual differences between Z. dauma and Z. aurea is still unclear and identification in the field is near impossible.

White's Thrush - Z. aurea

I got news that an immature Mrs. Gould's Sunbird had been seen at Shing Mun Valley lately, there were already a small crowed congregating below a few flowering Hong Kong Orchid Tree, there were a few Fork-tailed Sunbirds and Japanese White-eyes feeding nearby. It took a while for me to locate the Mrs. Gould's amongst the smaller birds, but once you locked on, it's red breast and wings are quite easy to pick out. It was feeding quite high up but gave fairly good views. Having missed the adult at Kadorie Farm a few years ago this immature male will have to do for now.

Japanese White-eye

Mrs. Gould's Sunbird - immature male

Someone spotted a Crested Goshawk nearby, this one actually caught something and was plucking what I believe to be a Spotted Dove. A flock of Red-billed Blue Magpies were not happy with it's presence and later chased it away.

Crested Goshawk - with prey

Finally, on Valentine's day I got a message from Kenneth that he got up to 30 Eurasian Siskins at Shek Kong Catchment! I looked at my watch and saw that I had an hour to spare before I had other things to attend to, so I quickly rushed there and luckily a dozen were still feeding on a Chinese Sweet Gum. Siskins are pretty rare in Hong Kong, and a fairly eruptive species, where one year we may get none and other year we get a decent size flock like this one! These had likely been pushed southwards by the strong northerly winds a week ago.

Eurasian Siskin - female

Eurasian Siskin - male

Hoiling heard a Koel calling near her home, spring is no doubt just around the corner now!