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Introduction

This is a review of the year 2023 of seawatching from Nam Kok Tsui on Po Toi Island. This year, surveys were only done in spring.

General

Let’s look at some general items first.

• Seawatching was only done during February, March, April and May.
• We seawatched for a total of 180 hours and 45, much less than the 630 hours in 2022.
• We watched the most in March (52 hours and 15 minutes), but this was certainly not the best month last year.
• The most birdy month was April, with 4,771 migrant birds counted. Even though we watched less this month than in April 2022 (4,314 migrants), we still saw more migrants.
• We counted a total of 8,535 migrating birds*. Due to less time spent seawatching, that number is way lower than in 2022 (33,133). We missed many thousands of migrants that passed Po Toi.
• We identified 48 migrating species during the year.

Here is the table from Trektellen (https://trektellen.nl/site/totals/3323/2023) with all the numbers:

totals.jpg (16.57 KB)

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* The total number on the above table of Trektellen includes 32 Indo-Pacific Finless Porpoises.

For reports on every survey, please consult these posts:

First Winter Period - http://www.hkbws.org.hk/BBS/view ... &extra=page%3D1
Spring - http://www.hkbws.org.hk/BBS/view ... &extra=page%3D1

Rarities

The only real rarity seen was Masked Booby (second or third record for Hong Kong – and Po Toi –, under review by the Records Committee). But this is a personal opinion. I refer to the yet to be published HKBWS Bird Report 2023 for a more ‘official’ stance.

Seabirds (i.e. pelagic or oceanic birds) that were surprisingly absent this year were Swinhoe’s Storm Petrel, Lesser Frigatebird and Red-footed Booby.

And the only rarity for our seawatch point was… a Richard’s Pipit (see species comments elsewhere in this report).

Weather

Weather and birds remained as complex and comprehensive as in the previous years. Being out there seawatching during spring and autumn migrating periods, regardless of the weather, is most important to see good species and/or numbers.

Storms

We didn’t encounter any storms while seawatching in 2023.

Map area and method

I refer to the 2021 review on these matters, as there is not much to report differently: https://www.hkbws.org.hk/BBS/vie ... amp;extra=page%3D1. The only change is that the red lightboat has been replaced by a buoy. I presume the location is more or less the same as the lightboat.

Additionally, I also would like to draw the readers’ attention to this post, about routes of offshore migrants in Hong Kong: https://www.hkbws.org.hk/BBS/viewthread.php?tid=30989

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List of observed seabirds and coastal migrants

This is the full list of all migrant species that we saw and counted. In case there’s an accompanied chart when relevant, I posted one for 2023 only (total counted per day) and a second for 2021, 2022 and 2023 (total number per standard week). In some cases, with just a few records in 2023, only the latter chart is published. These charts often say more than a thousand words, so the text is usually kept short.

Ducks

Some species of duck were unrecorded, as they were seen in late autumn and December during seawatching in previous years. This year, we did not do any seawatching during this time.

duck spec.

Very few ducks were seen in 2023, with just one unidentifiable to species on 16 May.

Garganey Spatula querquedula

Seen on only one day: 13 on 12 March.

There is a strong indication that the vast majority of ducks that pass Po Toi are Garganeys.

swift spec. Apus spec.

One on 17 May, either Pacific or House Swift.

Pacific Swift Apus pacificus

Only a few recorded: two at the end of April and four in late May.

Pacific Swift.jpg (39.31 KB)

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House Swift Apus nipalensis

Just one record, one on 19 May.

Oriental Turtle Dove Streptopelia orientalis

One on 25 April. Very uncommon as a coastal migrant off our watchpoint, with the only other record two in November 2021.

wader spec.

Many waders could not be identified. The reasons being too far, flying too fast and sometimes in bad lighting conditions. Most probably, a wide variety of wader species pass Po Toi, mainly in spring.

The total number of wader spec. (77) and large wader spec. (6) amount to 83, much less than last year (674).

Eurasian Whimbrel Numenius phaeopus

A total of 68 were counted, all at the end of April, with a highest count of 24 on 27 April. The chart below suggests that the peak for this species is the second half of April.

Eurasian Whimbrel.jpg (48.92 KB)

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Far Eastern Curlew Numenius madagascariensis

Only one record: a single bird on 27 April.

Ruddy Turnstone Arenaria interpres

There were two Ruddy Turnstones present near the watchpoint on 26 April; only one flew by as a migrant on 27 April.

Red-necked Stint Calidris ruficollis

Surprisingly not seen as migrants this year – or at least not identified –, but two where present on the rocks near the watchpoint on 26 April.

Red-necked Phalarope Phalaropus lobatus

A total of 1,300 were counted, of which 70% in April. Highest count 427 on 26 April.

The multi-year chart below shows a gap in the first weeks of April. This might simply be due a lack of seawatching surveys during this time.

Red-necked Phalarope 23.jpg (41.42 KB)

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Red-necked Phalarope 21-23.jpg (53.1 KB)

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Grey-tailed Tattler Tringa brevipes

Not seen as a migrant, but one bird present on 26 April.

March Sandpiper Tringa stagnatilis

Like last year, only one record and this year of just one bird on 26 April.

Wood Sandpiper Tringa glareola

First time observed since our surveys started in 2021, with three individuals together on 27 April. A relatively common bird in Hong Kong, but apparently not so as a migrant off Po Toi (at least during daylight).

Oriental Pratincole Glareola maldivarum

Only 3 singles were seen, on 20 and 22 March and on 28 April.

Oriental Pratincole 21-23.jpg (42.85 KB)

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gull spec. Larus spec.

Involves large white-headed gulls. 744 individuals were counted, much more than the 466 last year. Highest count 471 on 19 February, which is a record high for our surveys. These were probably mostly Black-tailed Gulls, as it seems this species is one of the earliest gulls to migrate north (compare the charts of Black-tailed Gull with Heuglin’s Gull).

large gull spec 21-23.jpg (46.89 KB)

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Black-tailed Gull Larus crassirostris

A total of 377 birds were counted, with a highest count of 129 on 21 February. That’s a new record count for our surveys, with the previous highest count 128 on 19 February 2022.

The second, multi-year graphs illustrates that this is an early migrant off Po Toi.

Black-tailed Gull 23.jpg (44.61 KB)

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Black-tailed Gull 21-23.jpg (47.02 KB)

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Slaty-backed Gull Larus schistisagus

One record: an immature on 16 May. This is an exceptional late record and apparently the first for May in Hong Kong. The previous latest record was 22 April.

Lesser Black-backed Gull (Heuglin's Gull) Larus fuscus heuglini

Only 337 individuals were counted. But as last year, the peak occurred in the second half of March.

Heuglin's Gull 23.jpg (41.29 KB)

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Heuglin's Gull 21-23.jpg (43.79 KB)

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tern spec.

During our surveys in 2023 only 449 unidentified terns were counted, compared to 6,555 in 2022 and 11,183 in 2021. The main reason is that we did not do any seawatching in the autumn of ’23, which is precisely the peak season for terns.

tern spec. 23.jpg (41.83 KB)

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tern spec. 21-23.jpg (48.97 KB)

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Gull-billed Tern Gelochelidon nilotica

48 individuals were counted, between 26 April and 20 May.

Gull-billed Tern 23.jpg (43.2 KB)

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Gull-billed Tern 21-23.jpg (46.69 KB)

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Caspian Tern Hydroprogne caspia

Only four birds were counted: two on 22 March and two on 23 March.

As noted already, no seawatching was done in autumn this year. According to our observations in 2021, the only year in which we did surveys in November, that month saw the peak of Caspian Terns. But neither in 2022 or 2023 could this be confirmed, although it seems unlikely that November 2021 was exceptional.

Caspian Tern 21-23.jpg (45 KB)

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Greater Crested Tern Thalasseus bergii

With much less seawatching hours, the number of Greater Crested Terns was low in comparison with previous years, with only 310 counted. However, the first individual occurred on 21 February, making it the earliest record for Hong Kong and de facto the first winter record. The previous earliest record was on 16 March.

Greater Crested Tern 23.jpg (37.79 KB)

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Greater Crested Tern 21-23.jpg (49.92 KB)

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Little Tern Sternula albifrons

Spring 2023 appeared to be an amazing time for Little Terns. No less than 1,185 were counted, between 25 April and 20 May.

The best day was 28 April, with 974 individuals. This is a conservative count, as undoubtedly a(n unknown) number of uncounted birds flew by as well: some small groups were coincidently seen flying over the rocks, an area where we usually don’t spend much time looking. This was by far the highest count ever in Hong Kong. The previous high count was 400 during the passage of typhoon Leo on 2 May 1999 (Cape D’Aquilar). As weather circumstances on 28 April 2023 did not appear to be extraordinary, it makes you wonder how exceptional (or not) a day with a thousand migrating Little Terns in Hong Kong actually is.

Little Tern 23.jpg (38.78 KB)

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Little Tern 21-23.jpg (44.94 KB)

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Aleutian Tern Onychoprion aleuticus

A total of 230 were counted. That number is low, even lower than the highest count in one day last year (312). This species most likely occurs in much higher numbers than our (fewer) counts last year would suggest.

Aleutian Tern 23.jpg (38.96 KB)

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Aleutian Tern 21-23.jpg (46.55 KB)

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Bridled Tern Onychoprion anaethetus

As noted in previous yearly reviews, a bit of a tricky species to count, as it is also a local breeder and these birds might fly along the same route, to feed out at sea, as migrants do. So counting locals for migrants cannot be excluded. The graph below nevertheless showed our attempt to only count what we believe to be migrants.

372 individuals were counted, between 25 April and 20 May.

Bridled Tern 23.jpg (40.24 KB)

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Bridled Tern 21-23.jpg (45.65 KB)

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Roseate Tern Sterna dougallii

22 migrating individuals counted between 29 April (just one on this quite early date) and 20 May.

A word on trying to distinguish the local breeders from migrants. Migrants tend to fly low, fast and straight ahead, and sometimes in mixed groups with other terns. Some Roseate Terns appeared as migrants in very small groups as well. We identify the species as local birds when they fly higher, much slower and often with more buoyant wingbeats, regularly feeding, and not in a straight direction. Locals tend to be vocal as well.

Roseate Tern 23.jpg (36.55 KB)

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Roseate Tern 21-23.jpg (43.46 KB)

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[ Last edited by badesc at 6/01/2024 08:54 ]

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Black-naped Tern Sterna sumatrana

Also a local breeder, of which the graph only shows counts of birds of which we believe were migrants. A total of 78 birds were counted, between 26 April and 19 May. The highest count was 38 on 29 April, which was a good count for Po Toi.

Black-naped Tern 23.jpg (45.29 KB)

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Black-naped Tern 21-23.jpg (45.09 KB)

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Common Tern Sterna hirundo

1,706 individuals were counted last year, between 29 April and 20 May. Interestingly, this includes two of our highest counts on Po Toi: 514 on 28 April and 534 on the next day.

As for the second, multi-year chart, I should repeat that we’re not sure if the peak really is in spring, as there is a large number of unidentified terns seen during autumn, of which many might be Common Terns.

Common Tern 23.jpg (40.53 KB)

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Common Tern 21-23.jpg (40.99 KB)

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Whiskered Tern Chlidonias hybrida

Only 19 Whiskered Tern were counted, which is quite a low number, compared to 88 in 2021 and 311 in 2022.

Whiskered Tern 23.jpg (42.38 KB)

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Whiskered Tern 21-23.jpg (42.28 KB)

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White-winged Tern Chlidonias leucopterus

Between 26 April and 20 May, a total of 603 birds were counted. As with other tern species mentioned above, such as Little Tern, Black-naped Tern and Common Tern, we counted the highest numbers of our surveys in one day last year: 402 on 16 May. The reason why a number of tern species saw daily records in 2023 is unknown to us.

White-winged Tern 23.jpg (47.56 KB)

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White-winged Tern 21-23.jpg (43.22 KB)

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jaeger spec. Stercorarius spec.

8 unidentifiable jaegers were counted. Earliest record last year was one on 21 February.
Additionally, it might we noteworthy that no Pomarine Jaegers were seen in 2023.

jaeger sp 23.jpg (43.24 KB)

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jaeger sp 21-23.jpg (43.25 KB)

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Parasitic Jaeger Stercorarius parasiticus

Not more than 35 individuals were counted, between 23 February and 17 May. The highest count was 12 on 28 April.

Parasitic Jaeger 23.jpg (40.68 KB)

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Parasitic Jaeger 21-23.jpg (45.68 KB)

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Long-tailed Jaeger Stercorarius longicaudus

Just 7 were seen and all on the same day, 27 April.

Long-tailed Jaeger 21-23.jpg (45.55 KB)

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Ancient Murrelet Synthliboramphus antiquus

A total of 8 were recorded, between 19 February and 19 March. The timing is consistent with what we’ve seen in 2022, with almost all records in the January-March period.

Ancient Murrelet 21-23.jpg (42.1 KB)

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shearwater spec. Ardenna spec.

Two records of singles on 27 April and 16 May. Nothing suspicious, just too far to be sure.

Streaked Shearwater Calonectris leucomelas

Compared to at least a thousand Streaked Shearwaters seen in 2022, last year was quite disappointing, with just 62 counted. Even though we were seawatching on the same dates as when record numbers appeared in 2022 (20 and 21 March). Highest count was 21 on 20 February.

Streaked Shearwater 23.jpg (41.95 KB)

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Streaked Shearwater 21-23.jpg (48.11 KB)

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Short-tailed Shearwater Ardenna tenuirostris

Taking into account much less observation time in 2023 compared to 2022, last year was a good one for this shearwater species. A total of 104 were counted (110 in 2022).

But the highlight was record counts for Hong Kong on both 16 and 17 May of 38 individuals on both days. That surpassed our previous record of 18 on 7 May 2022.

Short-tailed Shearwater 23.jpg (46.82 KB)

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Short-tailed Shearwater 21-23.jpg (46.43 KB)

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Bulwer's Petrel Bulweria bulwerii

Two records: singles on 16 and 17 May. Coincidently or not, on the same days we counted record numbers Short-tailed Shearwaters.
We’ve got not much to add to what we wrote about this species in the 2022 review. Just that both birds last year also occurred on days with force 2 to 3 winds.

Bulwer's Petrel 23.jpg (45.76 KB)

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Masked Booby Sula dactylatra

One record: a single adult on 27 April. If accepted, it would be the second or third record for Hong Kong (and Po Toi).

Brown Booby Sula leucogaster

Only 3 singles were seen, on 27 and 28 April and 18 May. That is much less than the 15 in 2022. But again, we did much more seawatching in that year than last year.

Brown Booby 21-23.jpg (43.27 KB)

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egret spec. Egretta/Bubulcus spec.

The families here are both Egretta and Bubulcus. 63 unidentifiable egrets were counted. Highest count 17 on 17 May.

Egret sp 23.jpg (35.86 KB)

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Egret sp 21-23.jpg (48.19 KB)

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Black-crowned Night Heron Nycticorax nycticorax

Same as last year, one record in April: one on 27th.

Chinese Pond Heron Ardeola bacchus

And same as last year for this species as well. Three records in 2023, all in the last week of April with the highest count 5 on 26 April.

Chinese Pond Heron 21-23.jpg (42.39 KB)

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Eastern Cattle Egret Bubulcus coromandus

With 68 individuals counted, 2023 was a poor year (386 in 2022, 150 in 2021). Highest count only 32, on 26 April. Surprisingly absent in May, the month in which peak numbers were counted in 2022.

Eastern Cattle Egret 23.jpg (43.33 KB)

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Eastern Cattle Egret 21-23.jpg (45.84 KB)

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Grey Heron Ardea cinerea

Very uncommon off Po Toi. Only one record of a single bird last year on 19 March.

Great White Egret Ardea alba

A very poor year for this species, with just four singles, on 21 March and on 26, 27 and 28 April.

Great Egret 21-23.jpg (51.02 KB)

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Medium Egret Ardea intermedia

Just one record of a single individual on 26 April.

Little Egret Egretta garzetta

Like Great White Egret, 2023 was a poor year for Little Egret. Only 31 birds counted, with the highest number 10 on 18 May.

Little Egret 23.jpg (39.1 KB)

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Little Egret 21-23.jpg (51.17 KB)

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Chinese Egret Egretta eulophotes

Our first encounter with this species from the watchpoint: two together on 26 April.

Osprey Pandion haliaetus

A scarce species off Po Toi, with just two on 21 March.

Peregrine Falcon Falco peregrinus

One record: one on 22 February.

Barn Swallow Hirundo rustica

129 Barn Swallows were recorded, with the highest count 19 on 25 April.

Barn Swallow 23.jpg (37.41 KB)

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Barn Swallow 21-23.jpg (53.51 KB)

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Eastern Yellow Wagtail Motacilla tschutschensis

Fifteen individuals recorded, exactly as many as in 2022, but without any autumn seawatching last year. And all but one occurred in April, while all spring records in 2022 were from May. The high count of 10 on 26 April was quite exceptional.

Eastern Yellow Wagtail 23.jpg (38.69 KB)

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Eastern Yellow Wagtail 21-23.jpg (45.46 KB)

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Grey Wagtail Motacilla cinerea

Four records, between 13 March and 29 April.

White Wagtail Motacilla alba

Only one record: one on 20 March.

Richard’s Pipit Anthus richardi

One record and the first for us at the seawatch point: one on 26 April. This species is regular at the grassy hills around the lighthouse, but this individual seemed to be a migrant, flying over to the North.

Acknowledgements

Many people have been supportive and helpful again. Thank you all!

wcaptain

THX for sharing