Dr Nial Moores, National Director, Birds Korea, December 30th 2024
Muan International Airport, centred at 34.991°, 126.383, is located next to the coast in southwestern Republic of Korea.
Following the tragic air crash on December 29th, and some suggestion that a contributing cause might have been bird strike, we have received some inquiries about whether the bird strike risk at Muan International Airport might typically be high or not; and also what species of bird might have caused damage to this aircraft.
No-one in Birds Korea has conducted robust surveys close to this airport in the last decade or so; and we do not have access to any information about this crash that is not already in the public domain.
Instead, to try to help reduce speculation, at this time we would simply like to share some of the data gathered during the National Winter Bird Census, conducted under the auspices of the National Institute of Biological Research within the national Ministry of Environment (NIBR 1999-2023). These same data can be independently accessed online in the database built by Andreas Kim.
The Winter Bird Census was initiated in 1999, and has grown to cover 200 or more sites nationwide, with most of the focus on wetlands and waterbirds. Initially counts were once a winter; in recent years, the number has increased to 2-4 counts each year.
ICAO (2020) state that 95% of bird strikes occur below 2,000 ft (=610m) and call for Wildlife Hazard Management Plans out to 13km from the airport, because on a normal approach aircraft descend below 610m approximately 13 km from the runway.
There are four Winter Bird Census count areas that are either completely (Muan Reservoir), largely (Muan-Mokpo Coast, Muan Gun-Hyeongyeong Myeon and Unnam Myeon) or are partially (Aphae Island) within 13km of airport operations of the Muan International Airport (Figure 1). The two latter count sites include tidal flat which has been designated as a Natural World Heritage Property.
Probably because of changes in land-use, following reclamation and airport construction, two of these count sites (Muan Reservoir and Muan-Mokpo Coast) appear to overlap in area. Although we do not have access to the original reports, we assume – based on all Census reports that we have seen – that the count data do not overlap in any way.
As there are few Census counts available for these sites for December, we have used January counts for five winters between 2019 and 2023 to indicate whether or not Muan International Airport is located in an area which is important for waterbirds.
Although not all of these waterbirds would have been counted within 13km of airport operations, the four Census sites combined supported a 5-year geometric mean in January 2019-2023 of more than 30,000 waterbirds (Table 1). For context, one of the criteria that the Ramsar Convention uses to identify internationally important wetlands is the presence of 20,000 or more waterbirds.
Table 1. January Counts of all birds recorded during the Winter Bird Census at the Four Count Areas which lie entirely or in part within 13km of the Muan International Airport.
| 2019 | 2020 | 2021 | 2022 | 2023 | ||
| 1 | Muan Reservoir | 1,541 | 1,163 | 2,038 | 2,946 | 3,621 |
| 2 | Muan-Mokpo Coast | 5,488 | 6,446 | 40,977 | 9,714 | 15,052 |
| 3 | Muan Gun-Hyeonggyeong Myeon & Unnam Myeon | 3,479 | 11,758 | 15,723 | 14,428 | 18,387 |
| 4 | Aphae Island | 5,607 | 1,135 | 4,763 | 5,286 | 6,544 |
| Grand Total | 16,115 | 20,502 | 58,438 | 32,374 | 43,604 | |
ICAO (2020) also provides guidance on how to develop a bird strike risk matrix. Simply put, in combination the greater the mass of the bird, the larger the flocks that the species forms, and the more frequently that species occurs close to airport operations, the higher the risk of damage to aircraft by bird strike.
There are many waterbird species in the Republic of Korea that form large flocks during migration or in winter. At least four such species have been recorded in substantial concentrations at one or more of these four Winter Bird Census sites in January (Table 2). These are Tundra Bean Goose Anser serrirostris 큰기러기 (with a mass of approximately 1,970–3,390 g: Kirwan et al. 2024); Greater White-fronted Goose Anser albifrons 쇠기러기 (with a mass of approximately 1,809-2,221 g: Ely et al. 2024); Baikal Teal Sibirionetta formosa 가창오리 (with a mass of 360-505 g: Moores in Kear 2005) and Great Cormorant Phalacrocorax carbo 민물가마우지 (with a mass of very approximately 2.3 kg: Hatch et al. 2020).
Table 2. Peak January Counts between 2019 and 2023 of four selected waterbird species at the four Winter Bird Census Sites within 13km of the Muan International Airport.
| Tundra Bean Goose | Greater White-fronted Goose | Baikal Teal | Great Cormorant | |
| Muan Reservoir | 893 | 550 | 0 | 857 |
| Muan-Mokpo Coast | 984 | 176 | 35,000 | 1212 |
| Muan Gun-Hyeonggyeong Myeon & Unnam Myeon | 1062 | 667 | 448 | 183 |
| Aphae Island | 443 | 0 | 0 | 77 |
As always we welcome corrections if any factual errors are detected in this post. Thank you in advance.
And finally, along with millions of people around the world, we would like to send our deepest condolences to all those affected by this terrible accident.
References
Ely, C. R., A. X. Dzubin, S. G. Mlodinow, G. M. Kirwan, C. Carboneras, and E. Garcia (2024). Greater White-fronted Goose (Anser albifrons), version 1.1. In Birds of the World (N. D. Sly and B. K. Keeney, Editors). Cornell Lab of Ornithology, Ithaca, NY, USA. https://doi.org/10.2173/bow.gwfgoo.01.1
Hatch, J. J., K. M. Brown, G. G. Hogan, R. D. Morris, J. Orta, E. Garcia, F. Jutglar, G. M. Kirwan, and P. F. D. Boesman (2020). Great Cormorant (Phalacrocorax carbo), version 1.0. In Birds of the World (S. M. Billerman, Editor). Cornell Lab of Ornithology, Ithaca, NY, USA. https://doi.org/10.2173/bow.grecor.01
ICAO. 2020. Doc 9137—Airport Services Manual—Part 3—Wildlife Control and Reduction, 5th ed.; ICAO: Montreal, QC, Canada.
Kirwan, G. M., C. Carboneras, and P. Pyle (2024). Tundra Bean-Goose (Anser serrirostris), version 1.1. In Birds of the World (B. K. Keeney, Editor). Cornell Lab of Ornithology, Ithaca, NY, USA. https://doi.org/10.2173/bow.tunbeg1.01.1
Moores, N. 2005. Baikal Teal. (pp. 605-608 in Keir [ed.] Ducks, Geese and Swans. Volume 2, published by Oxford University Press.
NIBR. 2019-2023. National Institute of Biological Resources (NIBR). 2019-2023 National Winter Census, conducted under the auspices of the Ministry of Environment. NIBR, Incheon, Republic of Korea. (in Korean: 겨울철 조류 동시 센서스 2008-2023. 국립생물자원관: 대한민국 인천.)
