Bird News from Nial Moores, Baek Seung-Kwang and Lee Su-Young
Supported by and in support of Yeoncheon County, research with a special focus once more on Long-billed Plovers was conducted by Birds Korea / Birds Korea Yeoncheon along the main streams and rivers of the Biosphere Reserve between July 1st and 8th. A total of 84 bird species and three mammals were documented, including stunning views of Ruddy Kingfisher (finally!); our first record in Yeoncheon of Eurasian Whimbrel (heard in flight on July 2nd) and Great Knot (one foraging at Horogoru, in the Imjin River on July 7th); and our first direct observation of River Otter (location intentionally kept secret; and a relevant proposal written by Baek Seung-Kwang which will be submitted to the county).
In addition to a single Mallard, a few Hill Pigeon, single Japanese Sparrowhawk and Eurasian Goshawk, multiple Chinese Sparrowhawks and two Fairy Pitta heard briefly, further records of note included (with order and nomenclature from AviList 2025 and the revised 2025 Birds Korea Checklist):
- Mandarin Duck Aix galericulata 원앙.
In addition to multiple singles and small groups, a family of eight ducklings was seen in Baekhak accompanied by their mother, confirming local breeding.
- Common Merganser Mergus merganser 비오리.
One on the Hantan River on 8th. This is the second time we have seen one in the summer months in the county. The species is known to breed in small numbers in neigbouring Gangwon Province.
- Watercock Gallicrex cinerea 뜸부기.
The decline in this species appears to continue, both nationally and in Yeoncheon, with only 10-99 individuals suspected nationwide in summer (hence the code of S5 in the Birds Korea Checklist). None were found by our survey in the CCZ again this year, and another site was also found no longer to support the species. During survey work we learned of one additional site, however, where the species is considered to be more or less regular in Yeoncheon, and we were invited to visit a site in the neighbouring province with 2+ calling males.
- Ruddy-breasted Crake Zapornia fusca 쇠뜸부기사촌
Two or three were found in a single area of rice-fields immediately adjacent to a small wetland patch in the CCZ, an area where we have the found the species previously.
- Long-billed Plover Thinornis placidus 흰목물떼새 (please note the new scientific name).
In total, we found only 27 at 20 locations, including one unexpectedly late chick on 2nd. This low number compares poorly with our counts made in the spring of both 2024 and 2025, and supports the possibility that at least some of the Long-billed Plover in Yeoncheon in March and April are not breeding locally, but are instead staging on their way north to the DPRK and Northeastern Russia, where the species is claimed to be a complete migrant by Wiersma et al 2024 in Birds of the World. Our own research in 2019, however, found Long-billed Plovers in Rason in far NE DPRK as early as March 15th, two weeks earlier than our Long-billed Plover survey in Yeoncheon in 2025.
Efforts were made to try to identify birds to sex and age. However, this was greatly complicated by the distance of most observations combined with the currently poor literature on identification of this species in the mid-summer. At two sites, we found what looked like pairs remaining in close association; and at three sites we saw what we identified as single young still attended by an adult (female-type), with one additional adult (a male type) seen within ~250m – perhaps at the outer edge of their summer home-range.
In total, we could only confirm one chick and three juveniles, with the juveniles identified by a combination of very brown head markings; cinnamon-rust fringes on the upperparts; obviously yellowish rather than pink legs; and rather narrow, whiteish orbital ring. An important caveat is that some individuals seemed to show two or three of these features, but also rather worn coverts or flight feathers, suggesting that adults – or perhaps second calendar-years – also can have yellowish legs, a weaker orbital ring and even rust fringes to the upperparts. If our ageing was correct, the success rate of nesting Long-billed Plover in Yeoncheon in 2025 was substantially lower than the success rate of 1.1-1.6 fledged per nest from 25-50 pairs between 2012 and 2014 in Kim (2017). Infrastructural work in the rivers in Yeoncheon (including several new bridges, paths immediately alongside the river, below the bund, and dredging – combined with very high levels of human disturbance – appear to be wholly unsustainable if this nationally threatened species is to survive in the Biosphere Reserve.
Additional observations of interest included two adults in active wing moult (one with apparently replaced inner primaries; the second with a wide gap in the wing); and one adult feeding on perched flying insects, pecked off from rocks – the first time we have seen such feeding behaviour.
- Little Ringed Plover Thinornis dubius 꼬마물떼새.
Thirteen individuals were found at a total of eight locations, including four juveniles – with three of these in a single brood, attended noisily by a parent.
- Dunlin Calidris alpina 민물도요
A breeding-plumage adult was briefly with the Great Knot on 7th: our second record in the county.
- Black-tailed Gull Larus crassirostris 괭이갈매기
A total of 133 of this marine-preferential species were counted at 13 different locations during the survey, with the largest numbers seen along the Imjin River on 7th, when one roost of 38 was counted; and 30 were counted flying upstream in only an hour, including several fresh-plumaged juveniles.
Birds were observed c. 70 km and more upstream of the Han-Imjin Estuary; and only c. 150km overland from e.g., Wonsan Bay on the east coast of the DPRK. Available evidence from the DPRK and the ROK indicates that substantial numbers of some species, including seabirds and waterbirds (including Scaly-sided Merganser), cross the Korean Peninsula at this its narrowest point.
Published satellite tracks of this species from two colonies (Baengnyeong and Tokdo) showed very wide post-breeding dispersal. Although this species is occasionally encountered inland along major rivers (most especially the Han in late winter, where thousands have reached Seoul), was this part of random exploratory dispersal, an exceptional movement, or part of an unrecognised but regular overland migration of the species from Yellow Sea colonies to the East Sea?
- Great Egret Ardea alba 중대백로
Small numbers of adult Ardea alba modesta were found; and at least three “post-breeding” adults (with orange-yellow bill bases and retained plumes) were seen with yellow tibia, which in winter would be used confidently to identify them as Ardea alba alba (a taxon not recognised by AviList 2025 as occurring in East Asia at all). Both of the alba-types which were seen well (in the images below) also seemed to have more extensive and paler green bare skin on the lores, feathering reaching further on the underside of the bill and subtly less orange, more of a yellow, tone to the bill. An additional confusing adult-type was also seen with near all yellow-pink legs. Unlike many of the modesta, the three alba-types were seen singly and not in direct comparison with Grey Herons (which alba are larger than, and which modesta are obviously smaller than). Are yellow tibia, paler green lores and more extensive feathering along the underside of the bill reliable for the identification of “nominate” alba in mid-summer too, or is there more variation in modesta than currently recognised? (if you have an informed opinion, please contact us!).
- Crested Honey Buzzard Pernis ptilorhynchus 벌매
Four were seen in total at 2-3 locations (including one “new” summer site), including two seen together. Possibly three or more pairs breed in Yeoncheon.
- White-tailed Eagle Haliaeetus albicilla 흰꼬리수리
An adult was seen over the Imjin River on 8th. This follows on from one photographed 10-15km downstream on 2nd (?) by Professor Kim Young-Gul, posted on eBird. In August 2024, two adults and one young were seen in the “spoonbills” site – indicating local breeding.
- Grey-faced Buzzard Butastur indicus 왕새매
A total of 9 or 10 were seen at 5-6 locations, with several of these in “new” locations. Based on current understanding, probably more than 10 pairs breed in Yeoncheon, concentrated in the CCZ in addition to more extensive hill forest.
- Oriental Dollarbird Eurystomus orientalis 파랑새
A total of 47 were counted at 16 locations. If this species is distributed more or less evenly across suitable habitat, it seems likely that the Biosphere Reserve supported 50-100 breeding pairs in 2025 (substantially more than the estimate of 10-20 pairs made in 2024, in part because of new areas with multiple pairs which were visited).
- Ruddy Kingfisher Halcyon coromanda 호반새
Twenty were heard in a total of 11 locations, many of which are additional to sites surveyed last year. This suggests that probably 30-40 pairs breed in the Biosphere Reserve.
- Black-capped Kingfisher Halcyon pileata 청호반새
Two of this Globally Vulnerable species were heard in a new location. One was apparently also present at a site in the southwest of the County well-visited by bird photographers.
- Ashy Minivet Pericrocotus divaricatus 할미새사촌
A total of six were heard in four locations, three of which are additional to sites where we found 2-3 pairs in 2024.
- Carrion Crow Corvus corone 까마귀
Apparently becoming more numerous in the County. A total of 33 were counted in 12 locations, with many of these locations additional to areas with the species in 2023 and 2024.
- Light-vented Bulbul Pycnonotus sinensis 검은이마직박구리
During previous surveys only found near to Jeongok. During the present survey five were found in three additional locations.
- Asian Brown Flycatcher Muscicapa dauurica 쇠솔딱새
Although forests were not surveyed, seen in two areas, including a very young, stripey-headed juvenile accompanied by two adults.
- Siberian Stonechat Saxicola maurus 검은딱새
Please note the revised English and Scientific names. Only 13, including five juveniles, were found in a total of eight locations. Although we did not survey much of the main southern CCZ where several pairs were found previously and we did not survey hill forest area where the species is also known to nest, this is a remarkably lower number than the 37 recorded in June 2022 and the 29 recorded in June 2024.
- Japanese Wagtail Motacilla grandis 검은등할미새.
Included here because the 2025 AviList, in following the online Birds of the World, still does not recognise that this species breeds regularly throughout the ROK in suitable habitat. Our survey found 39 individuals, including at least four family groups of adults closely followed by juveniles.
Remarkably, one rather advanced juvenile (with black patches appearing in the upperparts) on July 2nd sung several times in response to an “intrusion” by a Grey Wagtail.
Additional encounters of interest…
Our survey found 12 Soft-shelled Turtles (자라), with the coloration of the yellowish plastron seen well on one perhaps indicating that these are Amur Soft-shelled Turtle Pelodiscus maackii 북방계자라 rather than the morphologically similar Chinese Soft-shelled P. sinensis (this according to a reading of the account in Baek et al. 2022). The largest concentration was seven together at a site we already-identified as a high priority site for conservation, within the Flyway Network Site.
We also heard globally Vulnerable Pelophylax chosenicus 금개구리 at multiple sites; heard what was considered to be a globally Endangered Hyla suweonensis 수원청개구리 at a potentially new site (?); and enjoyed plentiful encounters with globally Vulnerable Korean Water Deer Hydropotes inermis 고라니 and one close encounter with a Raccoon Dog Nyctereutes procyonoides 너구리, apparently watching over a small pup. Dozens of damselflies and many thousands of dragonflies sp. were seen on the wing on several dates; and several Long-tail Spangle Swallowtails Papilio macilentus 긴꼬리제비나비 were among the more eye-catching butterflies and moths we encountered.
All data and subsequent analysis will be included in a report which Birds Korea will provide to Yeoncheon County in December.
References
Baek H-J, Kim P-J, Kim Y-C, Kim A, Kim S-H, Min M-S & Lee H. 2022. The complete mitochondrial genome of the Amur soft-shelled turtle (Pelodiscus maackii Brandt, 1858), from South Korea, Mitochondrial DNA Part B, 7:3, 498-500, DOI: 10.1080/23802359.2022.2051759
Kim In-Chul. 2017. 멸종위기종 흰목물떼새(Charadrius placidus)의 번식생태와 음성신호
연구. Unpublished (?) doctoral thesis.
Wiersma, P., G. M. Kirwan, and P. F. D. Boesman. 2024. Long-billed Plover (Thinornis placidus), version 1.1. In Birds of the World (J. del Hoyo, A. Elliott, J. Sargatal, D. A. Christie, and E. de Juana, Editors). Cornell Lab of Ornithology, Ithaca, NY, USA. https://doi.org/10.2173/bow.lobplo1.01.1
