Northants birds

That’s the question being asked by a number of birders after at least a couple of locals have voiced their opinion to the effect that the Ditchford Gravel Pits individual, currently present on Wilson’s Pit, is not a 100% pure Scaup. It has been there since its discovery on 16th January and I caught up with it last weekend (22nd) before going to see it again this morning.

The anomalies being cited are a) ‘small’ size, b) lack of prominent pale ear-covert patch, c) black on the bill tip not restricted to the nail and d) a pale subterminal band to the bill.

Have a look at the best of a bad bunch of digiscoped photos, below. With regard to the size it’s a little larger than a Tufted Duck, with a larger head and slightly bulkier body but it’s fractionally smaller than most Pochard present. The pale ear-covert patch, which develops in late winter and is variable, is present but not prominent (see first photo).

Let’s see if it becomes more obvious with time (assuming the bird stays, of course!). With regard to the pale subterminal bill band, it’s actually quite narrow, diffuse and slightly lighter than the overall bill colour and it’s not too uncommon for Scaup to show this contrast against the black nail. The latter colour also extends on to the bill tip, fanning out either side of the nail, but it is restricted to a small area (see second photo).

Presence of this feature – when more extensive – is often quoted as an indication of hybridisation but it is normal for first-winters to show a variable, though small, amount of black in this area. The white feathering around the base of the bill is tinged brownish and not particularly extensive.

These last two features point to immaturity and I think this bird is a first-winter female (first-year male would be expected to show some upperpart vermiculations and a darkening of the head and breast by now). All other features (overall shape, proportions and especially head shape) are fine for Scaup. So I don’t have any problem with this being a perfectly normal first-year female Scaup … but I’m willing to listen to any other arguments against this to learn in the event that I am wrong 🙂

The arrival in late autumn of Goosanders locally is a sure sign winter is on the way and the adult drakes, with their combination of red bills, glossy green-black heads and glowing, salmon-pink underparts are easy to identify and surely make this species one of the most attractive ducks on the British list.

With the drakes stealing all the limelight, little attention is paid, however, to ‘redheads’, the term used to describe adult females and first-year birds of both sexes. Given reasonable views, in many instances it is possible to age and sex certain individuals. Two photos of ‘redheads’, both taken locally yesterday and kindly sent to me by the photographers, prompted a bit of research and illustrate this nicely. The first was taken by Clive Bowley at Pitsford Reservoir. The clean white, extensive and sharply demarcated chin and throat, along with the darker lores and dark iris, make this an adult female.

Compare this with the one below, which was photographed at Abington Park Lake, Northampton by Keith J Smith www.kjs-images.com. This individual has a much more diffuse area of white restricted mainly to the chin, there are a few small blackish feathers beginning to appear on the throat (difficult to see) and there is a blackish half-collar at the base of the chestnut on the side of the neck which clinches this as a first-winter male. The outer part of the iris is pale which is also a feature of juveniles and many males.

Clive’s image also shows the serrated edges of the mandibles, which gives the genus Mergus the collective name of ‘sawbills’.

                                                                                   
Thanks are due to Keith and Clive for allowing the use of their images.

A Dark-bellied Brent Goose has been present with the goose flock on the main barrage lake at Clifford Hill Gravel Pits since Wednesday 2nd November, when it was found by Pete User. A first-winter (white-fringed secondaries and greater coverts and lacking the adult’s white neck patch), this is the only record so far this year of a species which produces just one or two records annually in the County. Late October to early November is the peak time. All previous records are of the dark-bellied race bernicla which breeds in northern Russia and winters on the east and south coasts of Britain. According to Mark Williams, who saw it on Sunday, it appears to have a bit of damage to its right eye and walks with a slight limp so it may stick around for some time yet. Some of my digiscoped pics below.

There are apparently no local records of the pale-bellied race hrota which breeds in Franz Josef Land, Svalbard, Greenland and northeastern Canada, wintering in northeast England

and Ireland and considered to be a separate species by a number of authorities. I would love to find one in Northants!