Observation of a Javan Myna Acridotheres javanicus on Hongdo, Shinan-gun, Ro Korea
Vivian Fu, May 29th 2021.
During the weekend of May 22nd and 23rd, 2021, Ms. Miyoung Choi and I visited Hongdo (Hong Island), Shinan County, Ro Korea. This small island is a well-known local tourist site, so on the day we landed there were about a hundred tourists there. In the afternoon we walked around the birding spots recommended in an NIBR publication and by other bird watchers. It was not rewarding in terms of the number of species, only 24 species were recorded. But still, we observed Black Drongo.
On May 23rd, after a non-rewarding hike to the observation platform for sunrise near the camellia forest, we decided to take a rest at the pebble beach at the backside of the village. It was around noon. While walking towards the pier a black-colored bird flew over us. From the white patches on each side of the wings, I got a feeling it was a myna. The bird then perched on an empty branch in bushes above the cliff just behind the pebble beach, where I could take a few photos, even though some distance away. Then the bird flew to the deeper part of the bush. The first thought was a Crested Myna which I am familiar with, but the bright yellow bill and white vent and underside to the tail ruled out this option. We did not stay long for the bird to come out again. Before the boat left we had recorded a total of only 27 species, including a singing Chestnut-winged Cuckoo (full eBird Checklist is at: https://ebird.org/checklist/S89020072).
After getting back to Incheon, I cropped my best two photos and shared them with other birding friends for suggestions. Some pointed to either Jungle Myna or Javan Myna. Dr. Ding Li Yong from Singapore immediately identified the bird as a Javan Myna Acridotheres javanicus, explaining the possibility of assistance by a ship from Singapore or Taiwan where Javan Myna has established small populations.
The photos were also shared with Dr. Nial Moores for verification, who along with Subhojit Chakladar also independently identified the bird as a Javan Myna.
I would like to thank Subhojit Chakladar, Leslie Hurteau, Dr. Todd Hull, Dr. Soyoung Sung, Dr. Ding Li Yong, and Dr. Nial Moores for their quick responses to queries about the sighting of this Javan Myna.
Remarkably, by the time I had written this post, Dr. Nial Moores told me there are now two Javan Myna present at the same site!
Additional Commentary by Nial Moores (May 30th 2021):
Many thanks indeed to Ms Vivian Fu for sharing these images and the story of their remarkable discovery of Korea’s first Javan Myna on the Birds Korea’s blog!
To the best of our knowledge, Javan Myna has not previously been recorded “in the wild” in the Republic of Korea (or elsewhere on the Korean Peninsula).
In the assumption that this bird was not a local escape (see below), this is therefore the first national record. As noted above, remarkably once the location of the sighting was shared with researchers based on these islands, two Javan Myna were seen together (and are still present at the time of writing: May 30th 2021).
What might the origin of these birds be? Context is needed to assess this record.
First, the bird trade in the ROK is not very well established; and an investigation of birds held in shops in Busan and Seoul in early 2020 conducted by Birds Korea did not find any Asian starlings.
Second, Hong Island is fairly remote from any major centre of population, lying more than 100km west of the mainland.
These birds therefore likely do not originate from within Korea.
Third, while more details are being sought, Javan Myna was introduced to Taiwan, where the species has a large and apparently self-sustaining population. eBird shows there are also records from Fujian Province, to the northwest of Taiwan. Is the species spreading northward there?
Fourth, species like Crested Myna are now known to be regular migrants across the northern part of the Yellow Sea, and the species has turned up several times during migration on Yellow Sea Islands in Korea. Hong Island is known as a migration hotspot, with part of the island surveyed regularly by staff from the National Migratory Bird Research Centre. The island has a long list of national rarities, especially species originating to the west and southwest of Korea, as only the open waters of the Yellow Sea separates this island from China; and a Crested Myna has already once reached neigbouring Gageo Island.
Fifth, in the week preceding the observation (and in the week following it) there were several days with very strong southerlies and south-westerlies, blowing up more or less direct from Fujian and Taiwan. These winds were associated with the start of a quite intense Jangmah or Maeyu rain front stalled across southern China and Taiwan, following on after a quite severe drought in the same region. Little doubt these same winds brought a Chestnut-winged Cuckoo to Hong Island that same weekend – a species that is just about annually recorded in the ROK.
Sixth, ship assistance seems easily the most plausible explanation for the three records of Common Myna in the ROK (most recently in Busan earlier this winter), especially as there is no population “in the wild” in China that we are aware of. And ship assistance cannot be ruled out for this and for some of the other rarities recorded this spring. However, it seems possible that these Mynas arrived separately. On 23rd, only one was visible. From late in the week, two were together. As these weather systems have persisted, multiple, staggered arrivals – driven by some factor – seem more plausible than first one ship then another sailing past to deposit Javan Mynas on the island.
And Seventh, 2021 has been exceptional in terms of odd weather, with strong winds and a high frequency of fast moving low pressure systems, especially in May. The year has also been an exceptional one for national rarities – some of which will very probably have arrived here without hitching a lift on a ship. While every month this year has had its highlights (e.g. Western Water Rail in January; national second Emperor Goose in February; fifth or so Demoiselle Crane in March; an embargoed national first on Heuksan and the second or third national Claudia’s Leaf Warbler in April), May is definitely a month for the record books. Moreover, pretty well all the month’s major rarities so far will most likely have originated in southern China and further south. They all seem to be spring overshoots. May started with the national second Besra on Socheong Island; continued with the first Marten’s Warbler and Grey-backed Shrike on Baekryeong Island (about 400km to the north of Hong Island) on 8th and 9th and the national first Oriental Magpie-Robin on Eocheong Island on 9th (see: https://ebird.org/checklist/S87706349), the day after the national second or third Square-tailed Drongo-Cuckoo was found there; the national second “golden-spectacled warbler”on Socheong Island followed on 22nd, photographed by Dr Kim Dong-Won; with the national second record of Ashy Woodswallow on Heuksan Island on 29th. Major national rarities reported so far today (May 30th) alone include: Scaly-breasted Munia on Hong Island (fewer than 10 national records); and Asian Koel and two Spotted Doves (fewer than 10 national records, and the first multiple arrival nationally) on Eocheong Island.
In the absence of contradictory evidence, it therefore seems most reasonable for now to assume that these birds come from the free-flying, introduced populations established in Taiwan – a distance of about 1,000km to the southwest – or from Fujian or points northward on the Chinese coast. It is, for example, only 500km across sea from the nearest Chinese islands to Hong Island: perhaps only half a day’s flight in 50km/hr winds. And again, in the absence of any other hypothesis, is it not reasonable to suggest that severe conditions (drought followed by floods) might well have been the trigger to encourage these birds to explore northward to reach Korea?
To help with assessing this record (as part of maintaining the quality of the Birds Korea Checklist managed by myself and Mr Jungmoon Ha, both of whom are also volunteer eBird reviewers), we would very much appreciate learning more about the distribution of Javan Myna in East Asia; whether they are known to undertake any movements or not; and also to learn of any additional out of range records of the species listed above from elsewhere within our wider region.
Thank you in advance!