Igidae, Busan Sept 22 and 24

Bird News from Nial Moores

On Saturday 22^nd in light southerlies with 7/10 cloud cover, seawatching from the north of Igidae found 55 large white-headed gulls moving south between 1420 and 1700, with additional highlights a juvenile Parasitic Jaeger south (my personal first in the ROK for several years) and a small dark alcid always too distant to see sufficiently well.

Scoped for 45 minutes as it slowly drifted away northward and away from the coast, notes and rough sketches taken at the time included the following: A small dark alcid, consistently appearing about half the size of Black-tailed Gulls in direct comparison – therefore suggesting Long-billed Murrelet or Ancient Murrelet in size/structure. However, the bill was much more prominent, and was completely or near-completely dark, deep-based, heavy, and quite long – narrowing distally – and was usually held downward. The bird also sat very low in the water, looked flat-backed and lacked a “cocked tail”, yet the neck was always apparent, and even sometimes obviously extended, especially when it was attacked by Black-tailed Gulls (seen 3-4 times). At such times the bird’s outline recalled that of a small grebe or (an even smaller!) coot. The plumage was blackish, and almost lacked contrast, at a range when plumage details and bill markings could be made out on Black-tailed Gulls close to it. At closest range (still probably >1km away, through a tripod-mounted 60x Swarovski under overcast skies) noted as showing some suggestion of a “white line” facially, near or around the eye, therefore recalling a miniature breeding-plumaged Spectacled Guillemot. The plumage also appeared somewhat paler just above the water-line, and it showed a whitish belly when rearing up during wing-flaps (suggesting that the bird was probably not dark with oil). Unfortunately, it was only seen wing-flapping properly towards and from the rear, when its wings looked all black above, and very round-handed. Its rear-end also looked “short” and rounded. Based on its all-dark plumage above and its heavy bill, as well as its status in Korea, the most likely ID would be immature Rhinoceros Auklet: a highly unseasonal record of a species previously recorded only once at this site, but which sometimes forms quite large flocks at other east coast sites in the mid-winter. However, at no time during the observation did this bird actually suggest the bulk or size of Rhinoceros Auklet, and several expected features (such as some orange on the bill; head and bill shape; usually cocked tail and white undertail) were also looked for but not seen …Instead, its size, structure and plumage all seem to suggest Cassin’s Auklet Ptychoramphus aleuticus: a species as yet unrecorded in Korean waters. (As a prolonged search for this bird on subsequent dates has so far proved unsuccessful, this seems to be yet another oddball following in the wake of Typhoon Sanba that simply “got away”…Here’s hoping someone else has better luck!).

On Monday 24^th, winds had picked up to a moderate north-easterly, and seawatching at the same point between 1250 and 1450 found much larger numbers of birds both moving and feeding offshore. Most numerous were Common Tern with c. 660 south in two hours and Streaked Shearwater (with 80+ north between 1400 and 1450). Counting became much more challenging as winds strengthened further, and large numbers of both species started to feed in dense, frenzied flocks – with four of five feeding groups containing in total at least 700 Common Tern and 30+ Streaked Shearwater. Surprisingly, however, the two highlights of the day were both landbirds. Checking the open ground close to the seawatching point, first up was a calling Raddes’ Warbler (always very scarce in the southeast) and even more unexpected a Long-tailed Shrike! The latter species is typically a scarce late autumn and early spring migrant to offshore islands along the west coast, and an even scarcer overwintering species. Although one recently overwintered at Joonam Reservoir, this is presumably the first record for Busan.