Monday, September 09, 2024

Cold Edge

Juvenile Scaup.  On the bus to Wainstalls this morning I realised that the bird I identified 3 days ago as Tufted Duck could be a Scaup.  I had forgotten that the plumages of young juvenile Tufteds and Scaups are identical, and that they can be told apart only by behaviour and structure. 3 days ago I had decided on my ID and seen what I wanted to see - in particular a something or nothing 'bump' at the rear crown: and I had ignored the obvious steep forehead and hefty bill.  Thankfully the bird is still present, and was not diving while I watched it.





It was diving constantly 3 days ago, staying underwater far longer than I have ever seen Tufted do (I estimate 1-2 minutes), and surfacing for only a few seconds. It took me nearly 30 minutes to get the single photo that I put on the blog.

Its bill is heftier (photo 1) and body broader (photo 2) than those of Tufted Duck.

There are small white patches at the sides of the bill (eg photo 3). And photo 5 shows a black leg.

Then there is the fraught question of the rear crown. Photo 1 shows spiky feathers where the crown meets the nape, and also down the whole nape. Photo 4 shows a rounded rear crown with slightly raised feathers from the front of the crown to the base of the nape. Because wind can cause head feathers to stand up, I think these can only be said to exclude Scaup if one of two things is present: a tuft, or a definite 'bump' that is consistently present in all photos.

All good fun, and better than spending hours looking at tarmac.

2 comments:

Daniel Branch said...

Hi Peter
This bird is a juvenile Tufted Duck. As with the previous bird, the head shape is wrong for Scaup, except that bird was an eclipse drake and as you correctly point out, this one is a juvenile.
The second opinion I consulted on the previous bird was the chairman of the London Rarities Commitee (who I know via Spurn), probably the recording area with the most wildfowl experience due to the number of birds in park collections in London.
All the best
Daniel

Peter Smith said...

Thank you Daniel. It is helpful to compare the bill in my first photo with side views of the bills of Tufted Duck and Scaup in a good photographic guide. (Mine is 'Europe's Birds' by Hume et al). Regards, Peter