Nuthatch that missed its moult (24 February 2003)

Today in my garden I caught two Nuthatches Sitta europaea, a male and a female, both together. This in itself was an unusual event - they are only the third and fourth for the garden in 23 years, following the first two, also a male and female caught together on 16 November 2001. But even more unusual was the state of plumage of the female. She had almost completely missed last autumn's moult and all of her primaries, secondaries and the left half of her tail were pale, bleached and abraded feathers grown in 2001. The photo below shows what the male looked like, and what the species in general should look like: bluish-grey all over (with a few lesser coverts, not visible in this photo, that enabled its ageing as a 5).

The female (photo below) looks obviously pale and with obvious contrast between her (moulted, bluish-grey) mantle, inner medians, head and uppertail coverts (and with a few outer greater coverts as well), and the rest of her feathers that are at least 18 months old.

More detail of the wings (below) show that last year she moulted the small and middle feathers of the tertials but none of the secondaries or primaries: these are symmetrical.

Note the abrasion, which is not as bad as I might have thought for such old feathers, but the bleaching is very striking, especially at the tips of the primary feathers. The covert moult is not quite symmetrical. She has two obviously unmoulted greater coverts on the left wing and old alula (except for the smallest feather on the right wing) but has moulted several of the innermost primary coverts without the corresponding primaries. Finally, she had moulted all of the right half but none of the left half of her tail:

I've had over 400 handlings of Nuthatches but never such an odd bird.

For the sequel to this capture, please see 'Retrapped Nuthatch recovers from missing last year's moult (12 September 2003)'.

David Norman.