Busan, June 9

Bird News from Nial Moores

In initially misty and humid conditions, a few hours in a different area to that usually visited produced an unexpected highlight: good views of Pacific Swift feeding and then resting on rock faces as they waited to feed soon-to-fledge young at crevice openings or at nests hidden safely out of sight.  The hectic comings and goings of 40+ of these superb aerial acrobats included a range of vocalisations and multiple squabbles, presumably as some birds had to use the same ledge to access nests happily buried out of view more deeply inside the cliff.

Although there seems to be little easily-accessible information on ageing of Pacific Swift, it seems highly probable that two birds half in view on a ledge at the centre of most of the fights between adults, were birds of the year, perhaps soon to take to the sky (see bottom image). Both of these showed e.g. a paler head and stronger supercilium than the adults. Even the adults showed rather more variation than expected based on typically poor flight views of the species, with some looking quite glossy above, and most showing obvious dark streaking in both their throat patches and across their rumps (features that are supposed to be shown even more strongly by the now split cooki).  Most seemed to have broader white rump bands (or at least more obvious rump bands) than birds seen last month on Baekryeong: is there much variation in this feature geographically? ( Or are these feathers somehow made more prominent when birds are near breeeding sites?)

It is worth noting that all images were digiscoped using a  superb and zoomed-up Swarovski scope over a period of about 20 minutes at some distance, and no attempt was made to approach the cliff-face or to search for actual nests. As all Birds Koreans know, our organisation has a strict policy of not posting images of birds at the nest, and of strongly discouraging disturbance of birds, especially when breeding (or roosting): the birds’ welfare must always come first.  Initially, the birds seemed oblivious to me and an angler stood more prominently near the cliff, but they did seem steadily to reduce their attendance at the cliff-face until after I had completely left the area –  suggesting that they were still stressed by my / our presence.

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pacswift5_Pacific Swift Apus pacificus ©  Nial Moores (top five images, adults; bottom image, probable juvenile)

Other species of note during the day included 135 Streaked Shearwater lazily moving south at the edge of the fog and mist over a 50-minute count period; singing and calling Grey-backed Thrush; a White’s Thrush; probably five Black Paradise Flycatcher; a pair of Oriental Dollarbird; and young Coal Tit in addition to young Varied, Eastern Great and Long-tailed Tits.

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