From a pelagic off Oahu, Feb 28, 2005, two types of plumages were present all individuals at end of complete moults. Some of the birds showed dark hoods, barred bodies, barred under and uppertail coverts and no distinct cap. The other birds were clearly pale morph adults. One of the barred-bodied birds is below. Why the two distinct "types" of plumages? All had dark underwing coverts, and therefore are adults. Or are the barred bodied birds not adults? Any suggestions? Note that this dark bird is just moulting in the outer primary. I recall that it was also growing outer rectrices.
Same bird (I think) is below.
Below is an obvious adult, pale morph bird. Again this bird is moulting in the outer primary, as well as underwing coverts. If the above bird is an adult, why is does it have a barred body while this one does not?
Another individual below, again moulting in outer primary or two. This bird has a longer R1. R1 probably is moulted in sequence with the other tail feathers, but due to its odd structure and length it takes a lot longer to grow than the other rectrices. Another option is that R1 is moulted again after the full tail moult begins? I must admit that the growth of R1 is one of the biggest mysteries to me, do they moult them twice in a year, or is there one moult and very slow growth? In fall you see adults in California with full streamers, and others without. The birds without streamers could be early tail moulters, the ones with full streamers late moulters?
A third adult below, a real white breasted male. This bird is a little farther behind on the wing moult than the others, and is still moulting secondaries. R1 are coming in, while the rest of the tail appears to be largely new.
How does one separate the forms tundrius, japonicus and calidus? This juvenile bird was at the Kona STP, on March 5, 2005. It looks somewhat like tundrius, but it lacked a good supercilium and was darker above and below than most I see. Could it be of one of the Asian races?
No question, just a picture I am happy with.
