I caught Tanjung Tokong at just the right time last week (16 Sept) to get some nice close views of Common Redshanks feeding on the falling tide. I’ll devote a separate post to adults of the various races we get here, but before focusing on the races, here are a few samples of the various plumages.
This one has already begun to moult into the duller, greyer first winter/first non-breeding plumage (a few scapulars, manlte and breast side feathers). In common with most waders, it will moult only the head, body and a few wing covert feathers in its first year.
The front bird is what is often termed a “second calendar year” bird. That is, it hatched in 2012 and is more than 12 months old. In its first autumn (last year), it moulted from juvenile to first non-breeding plumage (a head and body moult only), and then this past spring and summer, it underwent another partial moult into “first breeding” plumage. Although it’s called “first breeding” plumage, the bird possibly did not breed. What it probably did was to spend the summer well south of the breeding grounds and renew a few of its head and body feathers. Meanwhile, the original juvenile flight feathers and wing coverts became excessively abraded and bleached. [EDIT: Prof W G Hale tells me that he has recorded a female incubating eggs at 10 months old, so perhaps it did breed after all!].
A closer view of the same bird shows that it still retains some juvenile lesser coverts. The median coverts are mostly new “second non-breeding plumage” feathers, the greater coverts look like weakly patterned “first breeding” feathers, and the primaries are clearly very old and worn juvenile feathers. All in all, reminiscent of a scruffy teenager!
This is another second year bird, but it looks much smarter because it’s moulted most of the median and greater coverts, which are now adult-type non-breeding feathers. There’s still a line of tatty juvenile lesser coverts visible at the front bend of the wing, and the tertials on this side are still the old juvenile ones (interestingly, the set on the far wing have all been replaced). The very ragged juvenile primaries are yet to be replaced.
Another second year bird, aged by the presence of juvenile lesser coverts on the far wing.
Although I can’t see any juvenile lesser wing coverts on this bird, I think it’s probably a second year bird, judging by the excessively worn inner secondary and outer primaries, and the dull bare part colouration. The secondaries apparently did not attain the ‘correct’ length after the previous moult, but the new outermost secondary seems to be growing out to the proper length.
Once I start to look in detail at even a small flock of birds, I start to realize how little I know and how much there is to learn!