Monday, July 20, 2009

15th July: Pelagic trip off Tanjung Dawai, Kedah

I must want to see petrels and shearwaters VERY much! How else can I explain the suffocatingly rancid smell of fish guts left in the boot of my car under the sun for three days (which permeated the entire neighbourhood)? This was the preparation for making 'chum' supposedly irresistible to petrels, shearwaters and albatrosses(!).

Once aboard the ikan bilis boat, this would be transferred to a laundry basket generously donated by my wife (come to think of it, she must love me VERY much too!), and rounded off with a bottle of cod liver oil, before being suspended over the side of the boat to attract great flocks of tubenosed seabirds.

That was the plan. The chum was as spectacularly stinky as we could have hoped for, but the birds were sadly absent - yet again!

A small handful of Bridled, Black-naped and Common Terns, and couple of early returning Barn Swallows were the only reward for our hard labour.

According to all the bird books I can find, Bridled Terns either look like this, if they are adults, or else are juveniles. However, this was the only Bridled Tern in about 60 birds which looked like it should in the books.

Here's the same bird (upper right) with birds in more typical plumage.

The presence of extremely worn inner secondaries, outer primaries and a line of lesser coverts, with other feathers at different stages of wear show that this must be a first summer bird I suppose (ie one that is around a year old, and still retains some of its original juvenile wing feathers).

A similar-looking bird, slightly more advanced in wing moult.

This bird seems to have completed primary and secondary moult but to have retained some white-fringed median coverts. The broadly white-fringed mantle feathers are fresh and seem to be adult non-breeding type feathers. The extent of paleness on the mantle is quite variable.

This one seems to be an adult, but with some pale-fringed mantle feathers - the onset of post-breeding plumage?

The books say adults have white underparts, but this one shows quite strongly dusky-grey flanks.

Not the only one doing some head-scratching!

While there were no juvenile Bridled Terns around, suggesting that the flock was made up on non-breeding oversummerers, there were one or two fresh juvenile Black-naped, and the adults, like this one, were mostly worn, and had dropped their outer tail feathers.

The five or six Common Terns present were all first summer types which probably hadn't bothered to go north for the breeding season.

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