White-winged Scoter: how rare (or common) is it in Japan?

I had three main targets for a 10-day trip to Hokkaido, all of which were rather optimistic in one way or another: White-winged Scoter, Rock Sandpiper and Bald Eagle. 

There may be one or even two Bald Eagles lurking somewhere in eastern Hokkaido, not necessarily along the coasts, one of them would be a striking adult now. Any hope of connecting with one was beyond optimistic to be honest and needless to say, I didn't. 

Rock Sandpiper on the other hand should instill optimism you'd think, but truth is it's been a long-standing bogey bird for me. This going back to when, though scarce, they were more widespread around the rocky coasts of south east Hokkaido. Years past, numbers dwindled, eventually there came a time when none were reported from what had long been the most reliable site for them. Over the past two or three winters there has been one 'reliable' individual, I use the term advisedly as reliability has never been a quality I'd personally link with Rock Sand. This had the feel of a now or never opportunity and consequently I spent a lot of hours searching for it, managing brief views on just one occasion. True, if I'd stayed put day after day, I would have benefitted from much closer views but the species has already claimed enough of my Hokkaido time over the years, so once I'd seen it I never again spent more than an hour or two a day checking the spots it was likely to be. Likely not to be as it turned out! I'm not complaining though, it's fantastic to finally catch up with it.

Rock Sand, it may be distant but it's recognizable, and that'll do thank you very much.

That brings me to the last of my targets, White-winged Scoter, a species I've considered a major rarity in Japan since it was first recorded a few years ago, and thus another long-shot. 

Surprisingly, there was a sighting in Ochiishi Harbour about the time of my arrival in Hokkaido and this was our first port of call on the first full day's birding. The harbour was empty but a bird in the area gave rise to genuine optimism.

A few days later we were stopping, checking the sea, at various points along the Notsuke Peninsula, one stop thanks to a small party of Asian Rosy Finches. They must have moved on before we could get down to the beach and turning my scope to the ducks off-shore, I found what looked a dead ringer for White-winged Scoter, at about 300 metres when I first picked it up. Unbelievable! A male and female were constantly dipping behind the waves, gentle as they were, from our low position. They were probably no more than 100 metres off the beach but they were well along the shore and moving away quite quickly. Deep snow made any thought of trying to keep up with them out of the question. Luckily, we'd already encountered a flock of Stejneger's along this stretch of the peninsula which was an enormous help in judging the head shape at this distance. I may have been able to get reasonable shots when they were at their closest if I hadn't left my camera in the car, particularly to check the female (which remains unidentified), but I didn't need photographic evidence to convince myself White-winged was in the bag! 

Two days later we were at Wheel Rock off Hanasaki harbour and I was astonished to see another male and female, perhaps only 250 metres out, much better views from a higher elevation this time. Both were definitely White-winged. While we were watching, a couple of local bird-guides turned up (actually slid five metres down the near vertical snowy slope to where we were) and asked if we'd seen the "American" Scoters adding there were another six, with a single "Asian", just round the corner, off the other side of the point. Soon these birds hove into view teaming up with the birds already in front of us. The three male White-winged and single male Stejneger's were very obvious at this range with the light over our shoulder, but the female-types weren't so straight forward. A few days later, on another visit to the same spot, there were four male White-winged and five female-types present. 

So a minimum of nine birds and possibly 11 in total. Has White-winged simply been overlooked in the past? It's likely White-winged in Japan isn't the great rarity it was formerly thought to be.

A few shots of the 'Wheel Rock' birds...

Part of the flock.

No doubt about the males.

Classic White-winged profile and brown flanks.

Three shots of a juvenile-looking first winter.

A presumed first winter male (long in the face) with an adult.

A presumed female with less prominent bill.

A couple of shots of an immature male.

What about this one? I'm thinking adult female with some yellowish on the bill. It clearly has adult-type greater coverts and lacks the paler belly of first winters. The bill looks shorter and therefore deeper than the males.