Pintail puzzle

[wcleung]

I think this was largely a male northern pintail, but not quite. Was he just too young and in transition, or was he a hybird of some type (couldn't find any match after some effort)? Warning: bird seen in Hong Kong. Thanks in advance for any help. Cheers, Debbie

[Peter C.]

Interesting bird, but I don't think a hybrid with anything (although I'm not really the person to ask, when it comes to ducks! There's a whole sub-field of identification dealing with all the hybrids, domestic breeds, crosses between domestics and wild birds, etc...).

To me, the features - head colour, speculum colour, bill shape (and colour), back plumage - all look acceptable for pintail, just not adult male pintail. Females and young have a "barred" back like that, and I've seen some photos that show those spotted scapular plumes (which you can see as overlapping the left wing a bit in your photo). However, you can also see some more distinctly adult-pintail back plumes coming in behind (the dark-centered, very pointy ones).

I would suggest that there's nothing odd about this bird. It's just at the life stage where it is coming out of either juvenile or eclipse plumage, and is not quite there yet - hasn't replaced all the neck and body feathers, and hasn't grown the classic long tail yet. Transitional plumages like this are very confusing, and unfortunately, field guide often don't have enough room to show them.

Peter C.

[wcleung]

Many thanks!

I didn't realize the drakes have a winter plumage since I thought I've seen them in breeding plumage in "winter" before, but thinking back that might have been very late fall (end of Nov) and very early spring (Feb) and the concept of "winter" must be a little vague in places like Hong Kong. I used to attribute the much larger number of "females" to some kind of segregation (as for the mallards end of summer) so next time I should examine them carefully. This is why birdy is addictive. Incidentally, my local friends called the pintails "oh, there are a lot of these ducks" and moved on ...

This individual has a very white front neck, which I do not see in the drawings for the females or juvies in the Sibley guide. Does this fact point to a male for sure, or it's more complicated than 4 drawings in a guidebook?

Cheers, Debbie

[Peter C.]

Well, the thing is, it's an "eclipse plumage" occurring in consequence of the immediate post-breeding moult, and not tied to winter (or any other season) exactly. Ducks get this because they moult out all or most of their primaries at the same time, and simply can't fly for a while - so become much more reliant on camouflage for survival. I don't know the duration that the eclipse plumage is held for, but I think in some species (like Blue- and Green-winged Teal, Shovellors) it may be only a month or two - which explains why we see all these nice, brightly-coloured looking males again in December; they've already moulted again.

(Long-tailed Ducks make things even more complicated; they really do have a "winter" plumage, so a drake has three different "looks" every year.)

The white foreneck I really think must be a male feature. I certainly don't know the order of moult in ducks, but it (he) may have replace that first, and the back and wing coverts are still in progress.

PC.

[wcleung]

Many thanks for the explanation. What a strange locally "optimal" solution these drakes are assuming! Cheers, Debbie