A male Great-tailed Grackle Quiscalus mexicanus was seen in October 2024 (observer’s name unknown) in the port city of Busan. Based on a record in eBird, this bird was then re-found in more or less the same area in early March.
According to Birds of the World, the Great-tailed Grackle is a largely resident species of the Americas, which has increased its range enormously in the past century, but remains at best, “a short-distance, partial migrant at the northern limits of the breeding range” (Johnson and Peer 2022).
The Great-tailed Grackle is very tolerant of degraded habitats and of people, however, and there are a number of extralimital records of this species. This is because, according to an article on the Birds Guides website (posted on August 22nd 2024), “the species regularly takes advantage of ships to travel around, with multiple records from the Caribbean, South America and Hawaii” even reaching the Western Palearctic six times up to 2024. eBird lists five of these Western Palearctic records; and shows no records at all in Asia.
Exotic bird collections are still unusual in the ROK; and the bird in Busan was found only 5km from a massive port in perhaps some of the “best” habitat for the species in the city, comprising an odd mix of small wetlands and agricultural land set in amongst housing and shops. In addition, there is perhaps one previous record of a grackle from the Nakdong Estuary in Busan (this based on a single image, perhaps of a Common Grackle Quiscalus quiscula, seen in the early 2000s, which the photographer claimed was taken on Eulsuk island), and several records of Common Myna Acridotheres tristis.
Different checklists and different birders treat records of ship-assisted bird species differently. Some, like the American Bird Association, state that, “A species observed far from its normal range may be counted if, in the observer’s best judgment and knowledge, it arrived there unassisted by man. A wild bird following or riding a ship at sea, without being captured, is considered traveling unassisted by man”. Others, like the British Ornithologist Union Rarities Committee, only list those species which, “might be expected to arrive … naturally and without ship assistance given favourable circumstances (i.e. the species is migratory and its migratory route matches that of other species believed to occur naturally).”
The Birds Korea Checklist contains five major categories, with Categories One and Two containing all naturally-occurring, adequately-documented species. Category 5D has been created for records of largely sedentary species, which likely arrived in the ROK in a wild state on a ship.
Therefore, unless a captive origin can be traced for this particular bird, Great-tailed Grackle will join e.g., Common Myna Acridotheres tristis and House Crow Corvus splendens on Category 5D in our next update of the Birds Korea Checklist as belonging to a group of “Pioneering, largely non-migratory species…extending their fragmented global range through shipping … which have occurred in the ROK without establishing free-flying populations yet.”
References
British Ornithologists’ Union Records Committee: 31st Report. 2004. Published online in October 2004.
Johnson, K. and B. D. Peer. 2022. Great-tailed Grackle (Quiscalus mexicanus), version 2.0. In Birds of the World (P. G. Rodewald and B. K. Keeney, Editors). Cornell Lab of Ornithology, Ithaca, NY, USA. https://doi.org/10.2173/bow.grtgra.02