For the past three years, Martnaham Loch has been the site of a long staying drake Smew during the winter months. However, last year we were fortunate enough to be visited by a redhead Smew before the drake, unfortunately it did not stay, which at the time we thought was a shame. Having a pair of Smew on a loch, well who knows what could have happened! The drake Smew subsequently appeared and stayed the whole winter.
At the start of this winter we had high expectations for the return of the drake and maybe even the redhead. Checking last year’s notes we predicted that the redhead may appear early to mid November, while the drake usually appeared a month or so later. As if following a carefully laid out plan, the first sighting of the redhead was on the 9th November, would it stay long enough to be attracted by the drake to partner him for the winter?
Whilst numerous texts, such as Madge and Burn (1988), Beaman and Madge (1998), Ogilvie and Young (1998) and Snow and Perrins (1998), show both male and female adult and occasionally juvenile plumage, none show the transition of moult from male eclipse to full breeding plumage. The following are such observations of a drake Smew in moult.
Description of Redhead Smew
A number of visits to the loch rewarded observers with classic redhead views (see figure 1):
- The crown and hind-neck were a deep chestnut;
- The poor autumnal light made it hard to see the black patch around and under the eye to the base of the bill. This tends to blend into the chestnut on the ear-coverts, making it hard to see at the best of times;
- The chin, throat and sides of neck were white, providing a sharp contrast with the dark parts of head, neck and chest;
- The mantle feathers were sooty black, as were the back and centre of the rump;
- The tail was a dark grey;
- The chest was grey, while the sides of the chest were dark brown;
- The flanks were a dirty white, mixed with grey.
The Confusion and Suspicion
An afternoon visit on the 26th November provided a view of the Smew but in poor light. However, something did not seem right with it. With a cursory look you would say that it was the redhead, however, on closer inspection the chestnut brown crown appeared to be split down the middle by an intrusion of white. The wings also appeared to be showing more white than previously, though their appearance gave the impression of a ‘messy’ plumage rather than any developing pattern. The previously grey chest and dark brown sides were less bold in their colour and showed a white vermiculated pattern coming through.
|Figure 1: 20-Nov-01|
|Figure 2: 26-Nov-01|
|Figure 3: 29-Nov-01|
|Figure 4: 1-Dec-01|
|Figure 5: 4-Dec-01|
|Figure 6: 12-Dec-01|
This, of course, raised suspicion that this redhead Smew, presumed female, was in fact a male in eclipse, or a first year male coming into breeding plumage (see figure 2). This was confirmed by a visit three days later, on the 29th, when after an initial scan of the loch the Smew was eventually spotted, but what a difference. No longer could it be mistaken for a redhead now, it had the distinctive drake look about it. Though not in full breeding plumage, the chestnut brown head had all but disappeared leaving a faint hint of brown on the forehead and a faint brown band extending around the back of the head from the black eye patch. There was more white appearing on the wing, now becoming more recognisable as the white patch on the scapular and coverts. The chest was a lot paler than in the previous visit with white being the dominant colour and a residue of grey and brown forming the vermiculated pattern (see figure 3).
Subsequent visits saw the eclipse moult slowly vanish and the breeding plumage come to the fore (see figures 4 and 5). A visit on the 12th December saw the drake in his full resplendent glory showing the distinctive white with delicate black lines traced across his body (see figure 6). As to whether this was a first year bird or an adult in eclipse is a matter of debate. However, the fact that last year we had a redhead which disappeared, only to be replaced by a drake a week later suggests that it may have been the same bird. This could mean that it was a second year breeding bird, though Martnaham has had a Smew for three winters now. The first winter 1999/2000 saw its arrival later and its stay shorter, which could indicate that it was a first year breeding bird then. Or perhaps Martnaham is simply a Mecca for visiting Smew!
Timing of Moult
According to Blake (1993) Smew undergo a complete post-breeding moult, into eclipse, from mid-June to September. They moult their flight feathers simultaneously from mid-July to late September, during which they are flightless for about one month. A partial pre-breeding moult, from eclipse into the more familiar breeding plumage, starts when the wing is fully grown. This usually occurs from September to November. This male would appear to be quite late in starting its pre-breeding partial moult. It is unknown whether the lateness of the pre-breeding partial moult is a common occurrence among Smew within the British Isles, as they have the furthest distance to travel, due to the British Isles being at the Western limit for Smew migration (Cramp 1998). In this case observation has shown that pre-breeding partial moult affects the head, breast, sides and upper-wing coverts.
Chronology of Moult Observed
The classic drake Smew in its unmistakable breeding plumage is a good example of a bird that takes the focus away from its other plumage’s. This, allied with the fact that they are a latish winter visitor which we would normally have expected to have moulted prior to arrival, leaves many of us with the assumption that every redhead is a female, but as shown here this is not always the case. Clearly the arrival of early redheads warrants greater scrutiny, as they could just be a glorious drake in waiting.
- Baker, K. (1993)
- Identification Guide to European Non-Passerines, BTO Guide 24.
- Beaman, M. and Madge, S. (1998)
- The Handbook of Bird Identification for Europe and the Western Palaearctic, Christopher Helm.
- Cramp, S. et al (1998)
- The Complete Birds of the Western Palaearctic, CDROM, Oxford University Press.
- Madge, S and Burn, H. (1988)
- Wildfowl: An Identification Guide, Christopher Helm.
- Ogilvie, M. and Young, S. (1998)
- Wildfowl of the World, New Holland.
- Snow, D.W., Perrins, C.M. et al (1998)
- The Birds of the Western Palaearctic (Concise Edition), Volume 1: Non-Passerines, Oxford University Press.
This article originally appeared in Ayrshire Bird Report 2001 and Birding Scotland, 5(1), 29 – 32, January 2002, and is reproduced here with kind permission of the respective Editors.