Seabird survey led by Nial Moores with Amaël Borzée (Nanjing Forestry University and Birds Korea member), Bernhard Seliger and Felix Glenk (Hanns Seidel Foundation, Korea office) and “Team EAAFP” (Doug Watkins, Chief Executive of the East Asian-Australasian Flyway Partnership Secretariat, Vivian Fu, EAAFP Communications Officer, and Kang Seoyun, EAAFP Intern), joined also by James Banfill.
A record national high count of Red-necked Grebe and single presumed thayeri Iceland Gull and American Herring Gull were the outstanding highlights of our survey of marine-preferential bird species (“seabirds”) along the Daejin-Geojin coast from February 9th to 11th.
Funded by the Hanns Seidel Foundation (HSF) Korea office, the survey aimed to improve understanding of the current distribution and abundance of seabirds (defined as sea duck, grebes, gulls, alcids, loons and cormorants, in accordance with Moores et al. 2017) along this stretch of coast. This is to help inform discussions about possible conservation strategies for biodiversity in this part of the inner border region.
Stationary counts of birds were made from the excellent January Pension as they flew out of the marine DMZ on two mornings starting from 15 minutes before dawn; a 4-hour boat survey in slightly choppy seas was conducted on 9th; and birds were also counted along the coast from pre-selected vantage points on 10th and 11th. In this way our survey covered about 10km of coast, with likely steadily decreasing detection rates of birds from shore out to a maximum 11 or 12km from shore.
In addition, on 10th waterbirds were counted on Hwajin Po; and rapid assessment counts were made at eight additional points between Geojin and southern Sokcho: Bukcheon (Ganseong), Namdaecheon (Ganseong); Songjiho; fields near to Ayajin; Ayajin Harbour; Yeongnangho; sea off Sokcho harbour; and the inner part of Cheongchoho. These counts and observations were made to identify potentially important habitats and to assess habitat quality.
After exclusion of some counts to reduce double-counting of the same individuals, approximately 6,800 seabirds were logged by our survey along the Daejin-Geojin coast. Species included:
- Harlequin Duck Histrionicus histrionicus 흰줄박이오리. Eighteen in total, with another ten or so in Ayajin harbour.
- Stejneger’s Scoter Melanitta stejnegeri 검둥오리사촌. Only five were seen. A worrisome decline, even steeper than along some other stretches of ROK coast.
- American Scoter Melanitta americana 검둥오리. Only three males were seen. Until recently, this was the best stretch of coast in the country for seeing flocks of this species.
- Red-breasted Merganser Mergus serrator 바다비오리. Only 68 were counted along the coast.
- Red-necked Grebe Podiceps grisegena 큰논병아리. A conservative and internationally important count of 905 was made along this stretch of coast (most 2-5km from shore), with likely hundreds more present and missed. This is the highest count of this species known to us in the ROK.
- Great Crested Grebe Podiceps cristatus 뿔논병아리. A total of 624 were counted, contained with several loafing rafts of the species in small bays along the coast.
- Horned Grebe Podiceps auratus 귀뿔논병아리. Two or three of this globally Vulnerable and very patchily-distributed species were observed.
- Black-necked Grebe Podiceps nigricollis 검은목논병아리 A total of 359 were logged along this stretch of coast.
- Black-tailed Gull Larus crassirostris 괭이갈매기 Only small numbers (c. 80) of this attractive gull were found along the Daejin-Geojin coast. Our surveys at Hwaseong on the west coast suggest that large numbers are now back in the Yellow Sea close to some of their breeding colonies.
- Common Gull Larus canus 갈매기. Approximately 1,700 were seen. Of those seen well, a dozen or more 2cy looked to be heinei (based on “old” ID criteria of small size, white-headedness and long primary projection) while the vast majority appeared to be kamtschatschensis. This included a dozen or more adults which were photographed in flight and identified to taxon based on the extraordinarily detailed analysis of primary patterns laid out at great length by Adriaens and Gibbins (2016).
- Glaucous-winged Gull Larus glaucescens 수리갈매기. At least two adults and one First-winter were seen, with an additional 1-2 birds which were not seen well enough to rule out a hybrid origin.
- “Thayer’s” Iceland Gull Larus glaucoides thayeri 작은재갈매기 (?). After a tiring 4-hour boat trip, a quick scan of a few gulls on rocks in Daejin harbour suggested there was not much of note to look at. Images of the flock however reveal one gull that shows multiple features of an adult “Thayer’s Gull” (formerly treated as a full species, now returned to Iceland Gull by e.g., Gill et al. 2021).
- American Herring Gull Larus smithsonianus 옅은재갈매기. A 2cy gull in Ayajin harbour showed multiple features of this taxon, now recognized as a full species by Gill & Donsker (2021). Initial attention was drawn to this bird because of the striking combination of extensively replaced silver-grey scapulars, paleing head and paleing bill base contrasting with the very extensive dark brown wash on the underparts and on much of the rest of the upperparts. Other features, including heavily barred vent, extensively dark tail with heavily banded rump, and pattern on the greater coverts (mostly not visible in the images) also support identification as this species. Based on current understanding, American Herring Gull, observed here in a range of different age-related plumages, appears to be annual in very small numbers in the ROK. This is therefore perhaps the only species confined as a breeder to North America to be more or less regular in the ROK?
- Vega Gull Larus vegae 재갈매기. Only small numbers (c. 250) were seen. Most looked “typical”; at least two 2cys were harder to assign to taxon with any level of confidence. Note that Gill et al. (2021) still oddly list mongolicus as a subspecies of vegae – presumably because they have not yet reviewed much of the literature out there published in German and Russian?
- Slaty-backed Gull Larus schistisagus 큰재갈매기. Only small numbers (c. 270 in total) were present.
- Taimyr Gull Larus heuglini taimyrensis 줄무늬노랑발갈매기. Only four or so taimyrensis (a taxon still not recognized by Gill & Donsker 2021) were seen.
- Spectacled Guillemot Cephhus carbo 흰눈썹바다오리. Only four or five were seen in total.
- Ancient Murrelet Synthliboramphus antiquus 바다쇠오리. Only 28 were seen.
- Rhinoceros Auklet Cerorhinca monocerata 흰수염바다오리. Only nine or so were seen,
- Arctic Loon Gavia arctica 큰회색머리아비. The most numerous of the three (or perhaps four?) loon species seen during the present survey, but only 155 were counted. This compares very poorly with a previous high count of 5,500 here!
- Pelagic Cormorant Phalacrocorax pelagicus 쇠가마우지. The most numerous of the three cormorant species recorded during the survey, with 2,155 counted flying south close to dawn on the 11th.
Other observations
- Between 1,200 and 1,500 Greater White-fronted Geese 쇠기러기 were found in rice-fields c. 2km south of Songjiho (at: 38°19’28.35″N, 128°31’9.76″E). This count represents more than 1% of the estimated population of the species (Wetlands International 2021). This goose flock looked to contain at least one globally Vulnerable Lesser White-fronted Goose 흰이마기러기.
- Among the freshwater wetlands we visited, Hwajin Po supported the most diverse assemblage of waterbirds and the largest number of anatids. However, even though the lake was only one-third covered by ice, there were only 577 ducks present, including e.g., Mallard 청둥오리(313), Common Merganser 비오리 (87) Greater Scaup 검은머리흰죽지 (69), Tufted Duck 댕기흰죽지(30) and Common Pochard 흰죽지(21) all suggesting, as we saw a week earlier at the Hwaseong Wetlands FNS, that northward migration is now underway – albeit slowly. Although not especially rare in Korea, probably most notable here was a hybrid Mallard x Eastern Spot-billed Duck.
- The only shorebirds we saw were Sanderling 세가락도요 (26 in Ayajin harbour) and perhaps because of the lack of snow in the mountains, the only landbirds of note were two White-tailed Eagle 흰꼬리수리 on Hwajin Po; a pair of Red-billed Starling 붉은부리찌르레기 in Daejin; and only a single Siberian Accentor 멧종다리.
If any Birds Korea members or bird conservation organisations would like more information or to receive our reports, please contact us.
References
- Adriaens, P. & Gibbins, C. 2016. Identification of the Larus canus complex. Dutch Birding 38: 1-64
- Gill F, D Donsker & P Rasmussen (Eds). 2021. IOC World Bird List (v11.1). doi : 10.14344/IOC.ML.11.1.
- Moores, N., Choi H-A. & Seliger, B. 2017. Seabirds in the Inner Border Area of Korea – Goseong County, Gangwon Province. Unpublished version of report.
- Wetlands International. 2021. “Waterbird Population Estimates” . Retrieved from wpe.wetlands.org on Tuesday 16 Feb 2021
