Observations

Have I seen a female Scaup at Rye Meads?

Alan Harris considers how to tell your Scaup from your Tuftie

Have I seen a female Scaup at Rye Meads? Probably…. not.

The last documented Greater Scaup was a male on 16 March 2000, over 25 years ago……..

Yet most months of the year female Greater Scaup are reported, sometimes photographed. Those that availed themselves to closer scrutiny have all proven to be Tufted Ducks.

‘But it had a white face’ you cry. Yes, as do around 15-20% of female Tufted Ducks. There is more to it than that. Consider this before you claim your female Greater Scaup.

1. Greater Scaup are very rare in Hertfordshire.
2. Greater Scaup are obviously bigger than a Tufted Duck -the size of a Pochard. This is especially noticeable head on when they are clearly broader in the beam and wider-headed with chubby cheeks.
3. Head shape is important but you often have to watch the bird for some time before you can confidently gauge it as it changes due to posture, activity and mood. The peak of the crown on Greater Scaup is before or above the eye, the head (and importantly) the nape is rounded. The Tufted Duck has the peak of the head above the eye or beyond it, and the crown is usually fairly flat. When actively diving the nape may appear rounded but sooner or later the angular rear crown will become apparent, a divot or eventually a small tuft is diagnostic. This is why you have to take your time.
4. Bill shape is subtly different. The Greater Scaup has a classic ‘Donald Duck’ beak, with a curved profile especially the lower line of the lower mandible which angles upward toward the tip. So does the Tufted Duck, but it is smoother, less sharply angled.
5. Bill pattern is crucial. The Greater Scaup has a grey bill which becomes slightly paler toward the tip. The black tip is small, confined to the nail and flooding off a little to the sides, in contrast to the female Tufted Duck whose black bill tip forms a broad black terminal band across the tip, usually emphasised by a whiter subterminal band.

If you are still confident in your claim these features may help nail it.  Juvenile female Greater Scaup are often a rich chestnut –warmer in colour than a Tufted Duck, and rather uniform (many Tufted Duck are a colder brown and show an obviously darker breast). Adult female Greater Scaup have grey vermiculations (fine barring) to the flanks and upperparts (almost female Pochard-like), and there may be a pale half moon on the rear ear coverts, features not found on Tufted Duck.

Good luck!