To be or not to be a Lesser Scaup 19th November 2017

Farmoor Reservoir has seen its customary build up of wintering Tufted Ducks over the last month or so with the ducks being scattered in random groups over both areas of water that form the reservoir. It is always worthwhile to check each and everyone of these groups as sometimes a rarer duck such as a Common Scoter or Greater Scaup can be found amongst them. Both Common Scoter (November) and Greater Scaup (September) have been found this year, consorting with the Tufted Ducks.

One diligent observer counted the Tufted Ducks on 17th November, reaching a highly respectable total of 584 and amongst them found what he identified as a male Greater Scaup and subsequently posted an image of the duck on the Oxon Birding website. Later that evening an Oxonbirder posted a comment asking why it was not a Lesser Scaup as it had 'a slight peak at the back of the crown and a purple sheen on its head.'

On 18th November another birder posted a number of images of the supposed Greater Scaup and  it was re-identified from these photos as a Lesser Scaup, which is both a  national rarity and a 'mega' for Oxfordshire.

This meant that Saturday 19th November would see another influx to Farmoor, not of ducks but of local and not so local birders, all keen to add this to their National, County or just Year Lists. The weather conditions on Saturday, after the preceding day of constant rain, could not have been more benign. The air was still, the reservoir waters flat calm, the sky clear and there was a promise of the sun soon appearing.

As soon as the gates to the reservoir were opened at eight am birders made their way up the ramp from the car park to scan the reservoir. It took a little time to find the scaup as it was adhering to the 'Law of Farmoor' which requires any rare bird to be situated as far as possible from the entrance and car park thus entailing a subsequent  long walk to both find and get to it.

It was eventually located in the far southwest corner of Farmoor Two, the larger of the two reservoirs in the complex and birders, in constant contact by phone and text, honed in to see this rare duck. I was a little late in getting to Farmoor and was astounded to find the car park so busy at just before 9am, not so much with birders but with numerous ladies of a certain age clad in lurid lycra, setting off on some sort of run around the perimeter of the reservoir. Well I guess it makes a change from all the yachting and windsurfing people.

By the time I had walked the half a mile or so to get to the southwest corner of Farmoor Two a good number of Oxonbirds finest were already viewing the bird. I joined them and set about recording on my camera this exceptional event.

The Lesser Scaup was not that far offshore, feeding with a group of Tufted Ducks and attendant Coots, that were trying to mug the ducks each time they surfaced with what looked like freshwater mussels tangled in weed. The latter was what the Coots were interested in as their bills were not powerful enough to deal with the mussels.

Studying the bird I diligently noted the features which confirmed its identification as that of a Lesser Scaup. The head shape was right with a peak at the rear of the crown which stood out like a small bump, there was darkish grey, vermiculated plumage on its mantle and  the bill was pale grey with just the nail at the very tip being black. It all looked good.

I observed and photographed the Lesser Scaup, on and off, for over an hour. The one shot I desired most of all was of it flapping its wings, as then I could record a truly diagnostic feature of this species, the bi-coloured wing bar on the upper wing surfaces. The bar on the secondaries should be pure white but contrasting with the continuation of the bar on the primaries which should be pale brown. I watched and watched hoping to catch the moment when it rose up in the water, as ducks do, to stand on its bottom and to flap its wings but all it did was roll in the water to preen its white belly and then stretch its wings horizontally along the water's surface. This was no good.

I had given up any thoughts of wing bars and was adjusting my camera settings by focusing on the duck which had its back to me, when without warning it did just what  I wanted and flapped its wings two or three times in rapid succession. There was no time to think, I just clicked away hoping that the images would come out. I decided to wait until I got home to check if I had been successful.

The time arrived when some of us considered we had, for now, had our fill of the Lesser Scaup and decided to fill something else, our empty stomachs, and made our way down the central causeway to the Yacht Club cafe to indulge ourselves with a full English Breakfast and reviving tea or coffee. Sat in the crowded and noisy cafe we discussed the Lesser Scaup and other birding matters and then decided to go back for more scaup action, as it is not every day that such a rarity is available in our very own County.

'Lesser Scaup' with Tufted Ducks

We walked back up the causeway, turned onto the west side of Farmoor Two and found the scaup had obliged us by swimming a lot closer to the causeway, thus saving quite such a long walk as before. We reprised our actions of earlier, taking photos and chatting about the duck but there was now some discussion about the size of the bird and how it seemed a little larger than the Tufted Ducks when it should have been smaller or about the same size. No more was said and when, once again, we were walking back down the causeway, another question arose about the wing bars. Terry had some images of the duck in flight which appeared to show a wing bar that was not quite right, in that the contrast between the white on the secondaries and the pale brown on the primaries was not defined enough. The wing bar looked almost uniformly white  virtually all the way across the wing which is a characteristic of a Greater Scaup.

Making such a crucial identification critique, alfresco on the causeway, from an image on the back of a camera was hardly due diligence so we dismissed it for the time being and moved on, and anyway another image appeared to show a contrast in the wing bar.

That night I checked my camera and found I had got a passable image of the duck flapping its wings  and showing quite clearly the wing bars .The bar on the secondaries was pure white and the bar on the primaries was almost white when surely it needed to be darker. I decided to sleep on it and stay out of any controversy. Photos can sometimes be misleading, let's face it

The wing bar provides an indication that this bird is of suspect
parentage.There is too much white on the primaries, a plumage
 feature which suggests one of its parents is a Greater Scaup 
or a Tufted Duck

Today, Monday, found me having to go to Oxford on an unrelated matter but once that was finished at lunchtime I re-visited nearby Farmoor to take another look at the supposed Lesser Scaup that had now  commenced to sow minor seeds of doubt in my mind about its veracity. Frankly I was hoping to re-assure myself it was truly a Lesser Scaup.

Ian Lewington, our esteemed County Bird Recorder and whose identification skills are exemplary had just left the reservoir and, I was told, had adjudged the Lesser Scaup to be a hybrid between probably a Greater Scaup and a Lesser Scaup or a Lesser Scaup and Tufted Duck  and it would all be explained on the Oxon Birding website later. This was good enough for me and I readily accepted the verdict from an acknowledged expert.

I found the whole event educational and have learnt a lot about the identification of two closely similar duck species and to be very careful, if not meticulous, before coming to a definite conclusion. My identification skills are nowhere near those of Ian and so I happily and confidently accepted his judgement despite a feeling of slight disappointment. However, I had enjoyed a great day out birding with like minded friends and colleagues on Sunday and now, today, I just relaxed and chatted with Roger and Jeremy as we watched the hybrid Scaup, feeding and sleeping on Farmoor Reservoir and not giving a toss about all the fuss it has created.

As soon as the reasons why this duck is a hybrid are published on Oxon Birding I will make another blog listing the reasons along with some more photos of the bird.