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Po Toi Seawatch Year 2022

Po Toi Seawatch Year 2022

Introduction

This is a review of the year 2022 of seawatching from Nam Kok Tsui on Po Toi Island. Regular surveys were mostly done in spring and to a lesser degree (early) autumn.

General

Let’s look at some general items first.

• Firstly, there were no seawatching surveys during the year in November and December. I therefore would be careful with drawing too many conclusions, as it might simply be due to how much – if at all – we seawatched during any given month.
• We seawatched for a total of 630 hours, more than the 492 hours and 25 minutes in 2021.
• We watched the most in May (128 hours and 55 minutes), followed by March and September.
• The most birdy month by far was May, with 11,924 migrant birds counted. Last year, that was September, with 11,101 migrating bords counted. The difference between 2021 and 2022 is that we watched more in May 2022 than we watched in September 2021. The second busiest month in 2022 was September. It seems that May and September are the best months when it comes to the number of migrating birds off Po Toi.
• We counted a total of 33,133 migrating birds*, almost 50% more than in 2021 (22,354). This is mainly related to more seawatching, and maybe some improvement in planning and technique. The one thing that is sure, is that tens of thousands of migrants pass Po Toi every year.
• We identified 84 migrating species during the year.

Here is the table from Trektellen with all the numbers:



* The total number on the above table of Trektellen includes 62 dolphins. The counts also include some potential double counts of Streaked Shearwater, and Flesh-footed Shearwater (same individual seen on two subsequent days and counted as two on Trektellen).

For reports on every survey, please consult these posts:

First Winter Period - http://www.hkbws.org.hk/BBS/view ... amp;page=1#pid87510
Spring - https://www.hkbws.org.hk/BBS/vie ... &extra=page%3D1
Summer - https://www.hkbws.org.hk/BBS/vie ... &extra=page%3D1
Autumn - https://www.hkbws.org.hk/BBS/vie ... &extra=page%3D1

Rarities

I believe we encountered just two real rarities/vagrants: Flesh-footed Shearwater (first record for Hong Kong, accepted by the Records Committee) and Masked Booby (second 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 2022 for a more ‘official’ stance.

You could argue that we also encountered a few Po Toi rarities, which are otherwise more common elsewhere in Hong Kong, like Black-winged Stilt, Pied Avocet (first record) and Little Ringed Plover.

Weather

Weather and birds remained as complex and comprehensive as in the previous year. Be 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 went seawatching during two storms, Tropical Cyclone Chaba (http://www.hkbws.org.hk/BBS/view ... amp;page=1#pid88177) and Tropical Strom Mulan (http://www.hkbws.org.hk/BBS/view ... amp;page=1#pid88253).

Chaba was very fruitful, with two Bulwer’s Petrels and high counts for Hong Kong of Red-footed Booby and Sooty Tern, while Mulan was not, with just one Red-footed Booby.

Cold fronts

One cold front that had a profound impact on migrants occurred on 1 May. We noted an exceptionally fall of landbirds, such as swifts, Browns Shrikes and Chinese Sparrowhawks.

Map area and method

I refer to last year’s review on these matters, as there is nothing to report differently: https://www.hkbws.org.hk/BBS/vie ... &extra=page%3D1

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 2022 only (total counted per day) and a second for both 2021 and 2022 (total number per standard week). These charts often say more than a thousand words, so the text is usually kept short.

Black Swan Cygnus atratus

One record: a single bird flying northeast on 20 May. This is a Category III species (escaped or released from captivity), but a first for Po Toi.

Ducks

Some species of duck were unrecorded, as they were seen in late autumn and December during seawatching in 2021. This year, we did not do any seawatching during this time.

duck spec.

Unidentified ducks appeared in January, March, early October, and with a peak in September. I believe most of them were Garganey. A total of 303 were counted.

Garganey Spatula querquedula

With some more seawatching in early spring, small numbers were seen during the end of March and early April. Many more were counted in September, which seems to be the peak month for them. With a combination of very good conditions and birds flying much closer than usual, a record number of 1,007 were counted on 20 September. This was also the highest count for Hong Kong, ever.

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

Eurasian Teal Anas crecca

Only three Eurasian Teals were identifiable with certainty, on 18 February.

Tufted Duck Aythya fuligula

Only one record: one on 16 March.

Himalayan Swiftlet Aerodramus brevirostris

Two records, all in September (like in 2021): two on 9 September and one on 21 September.

needletail spec. Hirundapus spec.

One record: six on 1 May.

Pacific Swift Apus pacificus

Many more were seen in 2022 than in 2021, with a very clear peak in spring (April and May). Highest count 30 on 1 May.





House Swift Apus nipalensis

Same as Pacific Swift: much more were seen in 2022, but only from mid-April to early May (note that there were no surveys in November 2022, a month in which the species was seen in 2021). Highest count 62 on 1 May.

Rock Dove Columba livia

One record: one on 7 September.

wader spec.

The vast majority of 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. (640), small wader spec. (28) and large wader spec. (6) amount to 674. The chart below shows wader spec. records, with an obvious peak in the spring months.



Black-winged Stilt Himantopus himantopus

As in 2021, just one record of a single bird in early autumn, 9 September.

Pied Avocet Recurvirostra avosetta

Another rarity for Po Toi, as it has not been recorded previously. One record of two birds together on 27 February.

Pacific Golden Plover Pluvialis fulva

Not recorded in 2021, but a total of eight on 5 different days in February, March, April, and May in 2022.

Grey Plover Pluvialis squatarola

Mostly singles in early spring and early autumn. Four on 3 April.

Little Ringed Plover Charadrius dubius

Yet another rare wader for Po Toi. One individual on 22 March, flying over while calling.

Kentish Plover Charadrius alexandrines

One record: a single bird on 31 March.

Lesser Sand Plover Charadrius mongolus

Most sand plovers could not be identified, but a few flew close enough and were seen well. 13 on 30 March and three on 31 March.

Greater Sand Plover Charadrius leschenaultii

Same remark as under Lesser Sand Plover. Five on 29 March and three on 30 March.

Eurasian Whimbrel Numenius phaeopus

A total of 210 were counted. Highest count 61 on 25 April.





Far Eastern Curlew Numenius madagascariensis

Not seen in 2021, but seven on 16 April and two on 17 April 2022.

Eurasian Curlew Numenius arquata

Just three records: two on 31 March, three on 17 April and six on 22 September.

Ruddy Turnstone Arenaria interpres

There were one or two Ruddy Turnstones present near the watchpoint in early May, only one flew by as a migrant on 26 April.

Great Knot Calidris tenuirostris

Not seen in 2021 and only one record in 2022: 16 on 30 March.

Sharp-tailed Sandpiper Calidris acuminata

Just two singles were identifiable, on 30 March and on 2 May.

Curlew Sandpiper Calidris ferruginea

One record: six on 30 March.

Red-necked Stint Calidris ruficollis

A total of 76 individuals counted, between 30 March and 4 May. Highest count 50 on 18 April.

Dunlin Calidris alpina

Could be more common, but unidentifiable. Only one record of six on 31 March.

Terek Sandpiper Xenus cinereus

Yet another wader that wasn’t recorded in 2021. 26 were seen on 4 May in 2022.

Red-necked Phalarope Phalaropus lobatus

A total of 5,788 have been counted, the vast majority in spring. Highest counts were 821 on 7 May and 601 on 30 March. The high count in May is exceptionally for that month.





Common Redshank Tringa tetanus

Four records, of one single bird and three pairs, between 18 February and 25 April.

March Sandpiper Tringa stagnatilis

Surprisingly, only one record of 25 on 17 March.

Common Greenshank Tringa nebularia

As in 2021, just one record, but in 2022 in spring: two on 27 March.

Oriental Pratincole Glareola maldivarum

A lot more were seen in 2022 (68), compared to 2021 (5) and only seen in March, April, and May. Highest count fifteen on 27 March.



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gull spec. Larus spec.

Involves large gulls: large-white headed gulls and also possible Pallas’s Gull. 466 individuals counted, with highest count of 89 on 23 January.





Black-headed Gull Chroicocephalus ridibundus

In 2021, it was a species that occurred mainly in November and December, two months during which we did not do any surveys in 2022. Fewer individuals, less than ten on all but one day, were counted in January to March, with the highest count 47 on 15 March.





Black-tailed Gull Larus crassirostris

A total of 629 birds were counted. A gull that appears to be most regular in January and February. Highest count 128 on 19 February. One (adult) on 1 July is exceptional. Earliest individual for the second half of the year was seen on 11 August.





Vega Gull Larus vegae

Vega Gull L. v. vegae

Ten records, mostly of singles and in March, but seen from January until early April. Highest count five on 25 January.

Mongolian Gull L. v. mongolicus

Seven records, also mostly of singles, in January and February, with one early April. Highest count 13 on 27 February.

Slaty-backed Gull Larus schistisagus

Two records: single immatures on 3 and 26 April.

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

A total of 1,005 individuals counted, with a peak in the second half of March. Highest count 267 on 30 March.





tern spec.

We counted much less terns in 2022 (6,555) than in 2021 (11,183). This was discussed here: http://www.hkbws.org.hk/BBS/view ... mp;page=1#pid88308. Our highest count was 1,659 on 21 September.

I still believe the vast majority of unidentified terns are Common Terns and Aleutian Terns. But as is illustrated under both species – which could be identified with certainty – in this review, their peak is in spring, not in autumn. Yet, this should not be the conclusion, as the peak numbers of unidentified – and likely Common and Aleutian – terns actually occur in autumn. It remains one of the unanswered questions of bird migration off Po Toi: what species of terns move through during autumn, mainly September? Frustrating, as it is by far the most common group of birds that we see here.





Gull-billed Tern Gelochelidon nilotica

A total of 272 individuals were counted. First record on 29 March, last one on 21 September. Highest count was 62 on 26 April.
And, interestingly, most appeared in spring, not in autumn as in 2021. It’s a good illustration to be careful with some quick conclusions, as different results can depend on when and how often seawatching surveys have been undertaken.





Caspian Tern Hydroprogne caspia

From our surveys in 2021, and illustrated on the below graph (bottom one), the vast majority of Caspian Terns occur in November. As there were no surveys in November 2022 we counted only 16 Caspian Terns, compared to 263 in 2021. Highest count was just eight in 27 February.





Greater Crested Tern Thalasseus bergii

2022 was an even better year for this species than 2021, with a total of 2,105 counted, compared to 1,108. It’s one of the more regular migrant terns, which occurs from March to October, with September being the peak month. First record on 16 March, last one on 1 October. We counted a new record high for Hong Kong, with 201 individuals on 21 September.





Little Tern Sternula albifrons

This species seems to peak in spring. Because we did more surveys in spring in 2022, the numbers (781) were more than tenfold compared to those of 2021 (70). First record on 30 March, last one on 8 September. Highest count was 180 on 18 April.





Aleutian Tern Onychoprion aleuticus

Another species with a tenfold in numbers if we compare 2021 (142) to 2022 (1,434). And that is virtually certain mostly due to more surveys in spring last year. First record on 10 April, last one on 1 October. Highest count 312 on 7 May.





Bridled Tern Onychoprion anaethetus

Let me repeat what I wrote in the 2021 review. 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. And then, as in 2021, we see two peaks, in May and in August. A total of 2,063 individuals was counted, with highest counts of 248 on 8 May, just four days apart from the highest count in 2021 (12 May). First record on 15 April, last one on 21 September.





Sooty Tern Onychoprion fuscatus

Three records of five juveniles, all seen during the passage of Tropical Cyclone Chaba: one on 1 July, three on 3 July and one on 4 July. The three individuals were a new high count for Hong Kong.

Roseate Tern Sterna dougallii

Local breeder. A species which we encountered in far greater numbers in 2021 (203) than in 2022 (61). First record on 5 May, last one on 20 August. Highest count 18 on 20 August. The peak for this species seems to occur during a limited time between mid to late August.





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 92 birds were counted. Obviously, a peak in spring, with the highest count of 27 on 5 May. First record on 3 April, last one on 21 May. Surprisingly, no autumn records in 2022.





Common Tern Sterna hirundo

A total of 3,700 were counted in 2022, much more than the 1,176 in 2021. Again, the opposite of the previous year: the peak appeared in spring, not in autumn. And again, that’s mainly because of more spring surveys in 2022 than in 2021. But note that we’re not sure if the peak really is in spring, as there are a large number of unidentified terns seen in autumn of which many might be Common Terns. Highest counts 456 on 5 May and 447 on 4 May. First record on 16 March, last one on 1 October.





Whiskered Tern Chlidonias hybrida

Another tern species of which we had higher counts in 2022 (311) than in 2021 (88). Highest count 92 on 1 May. First record on 29 March, last one on 30 June. So, no autumn sightings in 2022.





White-winged Tern Chlidonias leucopterus

A total of 1,460 was counted (574 in 2021). Highest count 336 on 7 May. First record on 15 April, last one on 30 June. None seen in autumn, in contrast to 2021. But this really seems a migrant that mainly occurs in spring/May.





[ Last edited by badesc at 3/01/2023 17:02 ]

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jaeger spec. Stercorarius spec.

Recorded in both spring and autumn. Highest count 21 on 16 April.





Pomarine Jaeger Stercorarius pomarinus

With surveys in early spring, we counted much more Pomarine Jaegers in 2022 (46) than in 2021 (2). They migrate pass Po Toi much earlier than Parasitic Jaegers. First record on 16 February, last one on 18 April. Highest count 23 on 18 February.





Parasitic Jaeger Stercorarius parasiticus

No less than a total of 211 were counted. Highest count 43 on 25 April, which was a new high count for Hong Kong. First record on 21 March, last one on 30 September.





Long-tailed Jaeger Stercorarius longicaudus

A total of 13 birds counted. First record on 16 February, last one on 18 April. Highest count seven on 16 March.





Ancient Murrelet Synthliboramphus antiquus

We didn’t record any Ancient Murrelets in 2021, but a total of 78 in 2022. The reason is probably twofold: firstly, they might just be much scarcer in November and December, and secondly there were no surveys in 2021 until 29 March. In 2022, we record almost all Ancient Murrelets from January to March and only five on one day in early April. Highest count was 14 on 13 March, a new high count for Hong Kong. First record on 11 January, last one on 10 April.



storm petrel spec. Hydrobates spec.

There were two records of Swinhoe’s Storm Petrels Hydrobates monorhis in 2021, but none in 2022. However, we did see two unidentified storm petrels that most likely were this species: one sitting on the water on 6 May and one during Tropical Cyclone Chaba on 2 July. Hence, I still belief this is an annual visitor to Hong Kong waters and not a vagrant.

shearwater spec. Ardenna spec.

One record: a single bird on 30 September, most likely Wedge-tailed Shearwater.

Streaked Shearwater Calonectris leucomelas

2022 was a truly unprecedented year for this species. Yet, the question remains if this was an aberrant year or a more normal one. A total of 1,277 have been submitted to Trektellen, but the exact number of individuals is most probably somewhat lower. There were two periods, 17 to 19 February and 20 to 22 March, during which hundreds were seen off Po Toi but same birds might have been counted on different days. I believe the true number, conservatively estimated, would be around 1,000 for the year. Highest count was 479 on 21 March, by far the highest count for Hong Kong, ever. First record on 17 February, last one on 2 July.





Short-tailed Shearwater Ardenna tenuirostris

With more surveys in spring, we recorded a total of 110 in 2022, compared to 48 in 2021. Highest count 18 on 7 May, a new high count for Hong Kong. First record on 18 April, last one on 3 July. The peak is clearly in May, but note that there are also Hong Kong records in April, June, July, September and December.





Flesh-footed Shearwater Ardenna carneipeis

One record: a single bird on 20 and 21 March. Accepted by the Records Committee as the first record for Hong Kong.

Bulwer's Petrel Bulweria bulwerii

Three records: singles on 20 May, 2 and 3 July. We’ve seen two Bulwer’s Petrels in 2021 and three in 2022. Plus, Robert Hackel and I saw one from a boat in southern waters on 29 April. Note that we also saw two single all-dark tubenoses from Po Toi in both 2021 and 2022, which were very likely this species. There also have been records in Hong Kong adjacent waters, like two individuals seen and photographed by Shashika Bandara from a ship in mid-April 2022. And a single Bulwer’s was seen by Graham Talbot on 13 October 2021 from Cape D’Aquilar. I believe it all indicates quite clearly that Bulwer’s Petrel is indeed not a rarity and certainly not a vagrant to Hong Kong waters, but much more likely an annual, scarce passage migrant in (mainly) spring and autumn, and a storm-driven visitor in summer months. Our records on 29 April and 20 May were during calm weather, so we even do not need typhoons or storms to bring them to Hong Kong. Although, in any season (especially in summer), storms might help, of course.

Lesser Frigatebird Fregata ariel

On record of a non-migrating bird over Nam Kok Tsui on 19 June.

Masked Booby Sula dactylatra

One record: a singe adult on 6 May. If accepted, it would be the second record for Hong Kong (and Po Toi). The bird was also seen by others and also in Chinese waters. But when we first saw it from Po Toi, to the west-southwest of the watchpoint, it was well to the north of the red lightboat and thus well in Hong Kong territory.

Red-footed Booby Sula sula

2022 seemed like a good year, with no less than ten Red-footed Boobies seen. They were seen during storms, but also in the absence of a storm. Highest count five during Tropical Cyclone Chaba, a new high count for Hong Kong.





Brown Booby Sula leucogaster

2022 turned out to be a great year for Brown Boobies as well, with no less than 15 seen. There have never been so many records in Hong Kong. Prior to 2022 there were mostly single records per year and not annual. It’s unclear to me whether 2022 was exceptional or just the result of more surveys. Highest counts two on 29 March and 6 May. First record on 29 March, last one on 5 July.



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cormorant spec. Phalacrocorax spec.

One record: a single individual on 16 January.

egret spec. Egretta/Bubulcus spec.

The families here are both Egretta and Bubulcus. 357 unidentifiable egrets passed Po Toi, and, like in 2021, mainly in September. Highest count 111 on 10 September.





heron spec. Ardea spec.

2 unidentified herons, either Grey or Purple, were seen on 30 October.

Black-crowned Night Heron Nycticorax nycticorax

One record: two on 17 April.

Striated Heron Butorides striata

Two records: singles on 4 May and 21 September.

Chinese Pond Heron Ardeola bacchus

Only three records in 2022: one on 4 May, 3 on 15 May and one on 21 August.

Eastern Cattle Egret Bubulcus coromandus

More than twice as much counted in 2022 (386) than in 2021 (150). Highest count 132 on 2 May. First record on 21 March, last one on 30 September. The peak indeed occurs in May, but note the large number of unidentified egrets (see above), with a peak in September, of which many could be Eastern Cattle Egrets.





Grey Heron Ardea cinerea

No more than two records in 2022: one on 9 September and two on 30 September.

Great Egret Ardea alba

Similar numbers in 2022 (48) compared to 2021 (43).





Intermediate Egret Ardea intermedia

No records in 2021, but two birds in a flock of other egrets on 4 May 2022.

Little Egret Egretta garzetta

Similar numbers in 2022 (139) compared to 2021 (151). Highest count 44 on 30 March. First record on 8 February, last one on 1 October.





Osprey Pandion haliaetus

Four records, all singles on 17 and 18 April and 4 and 5 May.

Chinese Sparrowhawk Accipiter soloensis

Just one record, but of 55 individuals on 1 May.

Eastern Marsh Harrier Circus spilonotus

One record: one on 21 September.

Grey-faced Buzzard Butastur indicus

Two records: three on 17 April and 31 on 18 April.

falcon spec. Falco spec.

One record, presumably Amur Falcon, of a single bird on 19 May.

Peregrine Falcon Falco peregrinus

Three records: singles on 17 February and 3 April and 4 May.

Brown Shrike Lanius cristatus

Two records: a very unusual high count of 56 birds approaching Po Toi from the sea on 1 May, and one on 15 May.

Black Drongo Dicrurus macrocercus

One record: one on 21 September.

Chestnut Bulbul Hemixos castanonotus

One record: one on 4 May.

Chinese Bulbul Pycnonotus sinensis

One record: 40 on 13 March.

Barn Swallow Hirundo rustica

A total of 423 counted. Highest count 28 on 21 March. First record 23 January, last one 22 September, but most probably occurs year round.





Red-rumped Swallow Cecropis daurica

One record: two on 3 April.

Blue Rock Thrush Monticola solitarius

Occurs on Po Toi, but we saw just one flying over the sea towards the island on 1 May.

Eastern Yellow Wagtail Motacilla tschutschensis

Eight records of fifteens birds, all in May and September.



Grey Wagtail Motacilla cinerea

A handful records, mostly between 1 and 7 May. One single bird in autumn, on 21 November.

White Wagtail Motacilla alba

Six records of single birds, in March, April September and December.

Olive-backed Pipit Anthus hodgsoni

One record: one on 31 March

Acknowledgements

Many people have been supportive and helpful again. It’s a too long list of names. Thank you all!

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Po Toi Seabirding

Thanks for all the detailed writing-up, Bart.   

I,for one, am really looking forward to how this year turns out for Po Toi seawatching !
http://johnjemi.hk

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