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Po Toi Seawatch Winter 2021/2022

Po Toi Seawatch Winter 2021/2022

Here we are with the first survey of the 2021/2022 winter, i.e. December, January and February. As with autumn, there have been very few seawatching surveys in winter, particularly in December. That month is basically completely uncovered. Besides this survey, we plan another one in the second half of the month.

As we’ve entered the winter, let us first have a look at a seasonal forecast. I know, often the weather seemed of little influence to what we’ve seen so far, but we’re still somewhat paying attention to it. Here’s the forecast from the Hong Kong Observatory, issued on 29 November 2021 (source: https://www.hko.gov.hk/en/Whats- ... t-for-winter-202122)

“In the past month or so, sea surface temperatures of the central and eastern equatorial Pacific continued to decrease and became below normal in October 2021. Based on the latest oceanic observations as well as forecasts by a number of climate models around the world, the central and eastern equatorial Pacific are expected to remain colder than normal during winter 2021/22 (December 2021 – February 2022). The situation is likely to develop into a short-lived La Niña event. Statistical analyses indicate that when La Niña occurs during wintertime, winter temperatures in Hong Kong generally tend to be lower than those during the ENSO-neutral state. On the other hand, under the influence of global warming and local urbanization, winter temperatures in Hong Kong show a significant long-term rising trend, partially counteracting the effect of La Niña. Taking all available information into consideration, including prediction from climate models around the world, the temperature in winter 2021/22 in Hong Kong is expected to be normal to above normal.

“Although the average winter temperature in Hong Kong is expected to be normal to above normal, day-to-day fluctuations in weather and temperature can still be quite large with occasional cold weather. It is expected that the number of cold days in winter 2021/22 would be close to that of previous winter. Please refer to the latest local weather forecast and 9-day weather forecast issued by the Hong Kong Observatory. Cold weather refers to temperature falling to 12℃ or below. On average, there are about 14 cold days per winter. During the last winter, there were 14 days of cold weather.

“The impact of La Niña on winter rainfall in Hong Kong is not significant. The majority of climate models predict that the rainfall over southern China is likely to be normal to below normal in winter 2021/22.”


Of course, we were looking for some unusually cold weather, in the hope it would bring a few more ‘arctic’ species down to Hong Kong. But alas, at least according to the above analysis, we’d better have low expectations.

Anyway, February has seen the most records in Hong Kong of birds from the (far) north, so we might have to wait a few more months.

2 to 4 December

To start with, there was yet another cold front:



We didn’t pay too much attention to it regarding our planning and the survey took place after the cold front had arrived.

I started on 2 December, watching from 11h30 until 16h30. The weather was very nice, but not so much for seawatching from Po Toi. It was clear and sunny (yes, bad lighting) and with heat haze. Winds were blowing from the northeast, with force 4. Fairly good numbers of gulls and two species of terns.

Ducks:
9 Northern Shovelers

Gulls:
2 large white-headed gulls
191 Black-headed Gulls

Terns:
1 Common Tern
1 Caspian Tern

Also one gull/tern spec and 1 Barn Swallow. Here’s the checklist: https://ebird.org/checklist/S98350005

3 December was the only full day of this survey, from 07h00 to 16h30. Weather was exactly the same as the previous day. There was good passage of gulls today.

Egrets:
4 white egrets spec.

Ducks:
14 ducks spec.

Raptors:
1 Common Kestrel

Gulls:
18 large white-headed gulls
371 Black-headed Gulls
2 Black-tailed Gulls

Also 1 gull/tern spec. Most of the large white-headed gulls were in one large group of Black-headed Gulls and were most probably all 1st year Black-tailed Gulls. Here’s the checklist: https://ebird.org/checklist/S98393702

And 4 December was already the last (half) day, during which I seawatched from 07h00 to 14h30. The weather was a little different, with a few scattered clouds and force 5 winds, again from the northeast. It was a very quiet day, with only the falcon after 11h00. And surprisingly, compared to the previous day, there weren’t any Black-headed Gulls migrating to the west.

Ducks:
4 Tufted Ducks
2 Northern Pintails

Raptors:
1 Peregrine Falcon

Gulls:
1 large white-headed gull
7 Black-headed Gulls
2 Black-tailed Gulls

Terns:
1 Caspian Tern

Here’s the checklist: https://ebird.org/checklist/S98435301

Remarks:

As most records of (rare) northern species are in February, December would perhaps not be a fantastic month. Of course, we can’t draw much conclusions from just one survey, but it could be that this month will indeed be a rather quiet one. Apart from gulls, there are fewer southbound migrants, winter has just started, and it’s too early for any northbound migrants as well. A month that falls between the two migratory periods – autumn and spring – while perhaps too early for real winter visitors. But we do plan another survey this month, before Christmas, to see what’s out there.

And both bad lighting on sunny days and the heat haze causes us to likely miss some birds and being unable to identify others. Let’s wait for the second survey, but I think December will not be my favorite month for seawatching here.

But still, it was worthwhile:

1/ Tufted Duck was the first record for Po Toi. We’ve now – in autumn and so far in winter – observed no less than four new duck species for the island, the other ones being Northern Pintail, Northern Shoveler and Eurasian Wigeon.

2/ The count of 371 Black-headed Gulls was a record high count for Po Toi and Hong Kong southern waters.

3/ The Common Tern on 2 December was a new late date, the first December record and also the first winter record for Hong Kong.

So, even though we saw not that much, no seabirds and no rarities, we managed to get some fairly satisfying records.

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21 to 23 December

As planned, I did a second survey in December, before Christmas. Coincidentally, there was typhoon Rai, which moved towards Hong Kong.



It did a lot of damage in the Philippines, but was rather weak when it came close to Hong Kong and only the standby signal 1 was issued. At Po Toi, the weather and wind were not abnormal, but we might have been a day too late to take full advantage (if there was any) of the storm.

Our first seawatching day was on 21 December and it was cloudy, with a little bit of heat haze and temporary some drizzle. Winds were blowing from northeast and then from the north, with force 5 at noon and force 4 in the afternoon. Observation hours were from 11h45 until 17h00.

Raptors:
2 Eastern March Harriers

Gulls:
19 gulls spec.
10 Black-tailed Gulls
9 Black-headed Gulls
2 Mongolian Gulls

Here’s the checklist: https://ebird.org/checklist/S99217491

From now on, our surveys are also published on the well-known migration-records site Trektellen. Many of our sightings are (at least for the time being) omitted by eBird from bare charts and from general sightings-lists (but not from individual checklist). Trektellen will allow analysis of the full range of sightings. This will be clear when we post the 2021 review here. So here’s the count: https://trektellen.nl/count/view/3323/20211221

The only full day of this survey was on 22 December, when I watched from 07h00 to 17h00. (NB: the last hour or so of the day, has always been extremely quiet in December.) Cloudy, so with good lighting. Winds turning from north to northeast with force 3. Mainly gulls on this day, but I had hoped for higher numbers.

Grebes:
3 Great Crested Grebes

Herons and egrets:
3 Grey Heron
1 Little Egret

Waders:
1 Eurasian Curlew

Gulls:
33 gulls spec.
13 Heuglin’s Gulls
10 Black-tailed Gulls
10 Black-headed Gulls
1 Mongolian Gull

Terns:
1 Caspian Tern

Here’s the checklist: https://ebird.org/checklist/S99432682 and the count https://trektellen.nl/count/view/3323/20211222

The last day, 23 December finally saw good numbers of Black-headed Gulls, with either singles or dense groups of 30-80 birds. I watched from 07h00 to 14h00 and it was a cloudy early morning, but turned sunny later. Winds blew from the northeast, force 4 to (mainly) 5.

Ducks:
2 ducks spec.

Gulls:
16 gulls spec.
269 Black-headed Gulls
2 Black-tailed Gulls

Here's the checklist https://ebird.org/checklist/S99432723 and the count https://trektellen.nl/count/view/3323/20211223

Remarks:

Obviously, mainly gulls were seen. Just one (Caspian) tern and also very few ducks, herons and egrets. There is still migration going on, but numbers were low and there were long ‘dead’ periods, during which not a single bird was seen. It has been most birdy from roughly 07h00 to around 10h00 and again from 13h00 to around 15h30.

All Black-tailed Gulls involved 1st calendar year birds.

The 3 Great Crested Grebes – one group – were only the second record for Po Toi. The previous record was a dead bird on the shoreline in the harbour of Po Toi (Geoff Welch in litt.). I believe they could actually migrate in small numbers off Po Toi, but we’ll have to wait for further winter surveys to see if we can confirm this.

[ Last edited by badesc at 27/12/2021 10:20 ]

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December 2021

Let’s wrap-up December. There were two surveys, with six observation days: two full days and four half days.

Generally, number of birds were rather low. The most numerous species from November, Black-headed Gull and Caspian Tern, were much less numerous in December. Only 288 Black-headed Gulls and 5 Caspian Terns were counted. A late Common Tern on the 2nd was noteworthy.

Also, no seabirds were seen.

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11 to 13 January

Our first survey of the year was planned during these 3 days.

Arriving with the 10 o’clock ferry, I started seawatching on 11 January from 11h45 onwards, until 17h00. The weather was bright and sunny, but with the usual winter heat haze. Winds almost always seems to be blowing from the same direction in winter, so NE winds, force 4 decreasing to 3 in late afternoon.

The first bird of the year was a Caspian Tern. It was flying westwards, but decided to land on the rear end of a container ship and enjoy the ‘ride’. The year started well, with also 2 Ancient Murrelets.

Seabirds:
2 Ancient Murrelets

Gulls:
15 gulls spec.
7 Black-headed Gulls
1 Heuglin’s Gull

Terns:
2 Caspian Terns

Here’s the checklist on eBird https://ebird.org/checklist/S100535631 and the count on Trektellen https://trektellen.nl/count/view/3323/20220111

After a fairly good day, we looked forward to 12 January. However, you can’t really predict what you’re going to see and the birds decide to show up or not, no matter how good or bad the previous day has been, or how good or bad the weather looks like. You have to take it like it is. And, oh boy, this second day was an extraordinary quiet day. Luckily, such days are very exceptional. Apart from an unidentified migrant bird early morning, I saw only two (!) migrants during the whole day.

You could argue I should have quit early and not staring at an empty sea for 9 and a half hours, but of course you don’t know in advance that the day will turn out like this. And noticing that there are days in January with almost no birds is valuable data as well.

Seabirds:
1 Ancient Murrelet

Gulls:
1 Black-tailed Gull

For what it’s worth, here’s the checklist https://ebird.org/checklist/S100687720 and the count https://trektellen.nl/count/view/3323/20220112

It’s regularly the case that a good day is followed by a less good day (bad days don’t exist), but also that a less good day is followed by a good day. So, not giving up hope, we were ready for seawatching on 13 January, from 07h00 until 14h00. A cloudy day, with limited visibility, and similar winds, but less forceful. And more birds; less birds than the day before would be almost impossible anyway.

Seabirds:
7 Ancient Murrelets

Egrets:
2 Great Egrets

Gulls:
1 gull spec.
5 Black-tailed Gulls
5 Black-headed Gulls

Here’s the checklist https://ebird.org/checklist/S100687829 and the count https://trektellen.nl/count/view/3323/20220113

Remarks

Admittedly, very few migrant birds. Caspian Terns and most Black-headed Gulls flew westwards, but all Ancient Murrelets, Great Egrets, most large gulls and all Black-tailed Gulls flew north-eastwards. So soundbound and northbound migration respectively. That indicates that we’re seeing both migrants: the last ones of the autumn season migrating south and the first ones of the spring season migrating north. Interesting will be our next survey(s) and to see if the northbound migrants will now start to increase in numbers. I do expect every subsequent survey to be better than the previous one, with a climax in April (but that remains up to the birds…).

Noteworthy and an eye-catcher to many, were our daily observations of Ancient Murrelets, all flying straight to northeast. (Two birds landed abruptly on the sea when approached by a Black-tailed Gull, but they were flying to the northeast before that.) It is supposed to be “rare” in winter. So seeing 10, and seeing them every day during our survey, is interesting, to say the least. And with 7 on 13 January, we were close to the highest count, being 9 on 19 February 2006. Normally, the numbers peak in March. Also, they did not appear before 09h40 and the majority was seen between 11h00 and 14h00. We’ll definitely keep an eye on these cool birds in the coming surveys, but I would not be surprised if we’ll see still higher numbers, and eventually a change to their winter status in Hong Kong.

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16 January

During the previous survey this month, the majority of the few migrants appeared during noon. That brought me to the idea to do surveys on Sundays, as the first ferry (from Aberdeen) leaves at 08h15 in the morning and the last one from Po Toi returns at 18h00. That actually provides plenty of time to seawatch. In particular for observing Ancient Murrelets, which – so far – have turned out to be migrating specifically around noon (that is an observation, not yet a conclusion). Hence our first one-day-survey.

So, I could start seawatching from 09h25. As there were no more birds after about 13h00, I watched until 15h50. If gulls or so would have started to appear during the afternoon, I would have prolonged the survey to 17h20.

It was cloudy for most of the time, with winds blowing from the northeast with force 4. It was one of the foggiest days that I have encountered, with visibility limited to roughly 4 km. I couldn’t even see a hint of the Dangan Islands.

Seabirds:
4 Ancient Murrelets

Cormorants:
1 cormorant spec.

Gulls:
1 large gull spec.
2 Black-tailed Gulls

Here’s the checklist https://ebird.org/checklist/S100898449 and the count https://trektellen.nl/count/view/3323/20220116

Remarks:

Not that many remarks for just one day of seawatching, with still very few migrants. But Ancient Murrelet was nevertheless de facto the most numerous species, again.

The cormorant could either have been a Great Cormorant or a Japanese Cormorant. I was unable to see any characters that would strongly suggest one of those species. Great Cormorant is an abundant winter visitor in Hong Kong and is most likely to be seen. Japanese Cormorant is regarded as a rare visitor with only 6 accepted records. The sea area and rocks around Po Toi could potentially be suitable for this species, more so than for Great Cormorant.

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