Wildlife Group - Swans and Geese
December 2020
The guide below to swans and geese has been prepared by the Wildlife Group's bird expert John Wills:
We start with the swans. Very large white birds, what's not to like and how hard can that be? However, three species of white swan occur in the UK: the familiar and widespread resident Mute Swan; the Whooper Swan - a fairly common winter visitor, particularly here in the Don Valley; and a rare visitor, the Bewick's Swan. The first two are fairly easy to separate from each other if you look closely at their beaks, whereas the Bewick's looks very similar to a Whooper and has to be examined carefully. The chances of finding one are few, but you never know.
Mute Swans are common all over the UK, on lakes, lochs, rivers and on park ponds. They number about 23,000 in summer, increasing to about 50,000 in winter with juveniles and some immigrants from frozen northern Europe; there are 5000-8000 in Scotland. In our area, they are numerous on Loch of Skene (can number 100 or more) and further north at Loch of Strathbeg.
About 16,000 visit the UK and Ireland each winter, primarily to Norfolk, N Ireland and Scotland. The total Scottish figure is about 1,600, with up to 1000 at Loch of Strathbeg and 150-200 in our immediate area of the Don Valley. The latter figure represents about 1% of the national total and is therefore of national conservation significance - hence the inclusion of the riverine habitat between Alford and Kemnay as a recognised conservation area within the next Aberdeenshire Local Development Plan. Quite large groups are often seen feeding and resting on local stubble and brassica fields between Monymusk and Kemnay, and at Whitehouse and Keig between Monymusk and Alford. They all probably roost on the River Don.
The Greylag is the largest and bulkiest of the grey geese. It has mottled and barred grey and white plumage and a prominent orange beak and pink legs. It has a loud nasal cackling call similar to that of the domestic goose: "ahnk-ang-ang", uttered on the ground or in flight. The name 'Greylag' comes from the old English 'Grey Lag' meaning grey goose; 'lag' derived from the call 'lag-lag-lag' used to drive or summon farmyard geese. Although not as numerous as Pink-feet, they can nevertheless be found in quite large groups on stubble fields, with up to several hundred within mixed flocks with Pink-feet.
Pink-feet are very similar in appearance though a bit smaller. The noticeable identifying differences are a smaller black beak with a pink band and somewhat darker head and neck. They arrive in Scotland in late September and can be seen in very large flocks, numbering often in the thousands, feeding on local stubble fields. They can be very mobile, moving noisily between fields, before transferring late in the day in characteristic V-shaped skeins, often after dark, to their waterbody roosts, before leaving again early the next morning back to the fields to feed. They can be seen in large numbers on Loch of Skene where their noisy early-morning departure is a spectacular wildlife event. Their call is a higher pitched 'ink-ink' compared to Greylags.
The monthly winter counts at the Loch of Skene tell an interesting story. When I first took over the counts in the late 90s it was a regular roost for Greylags with up to 10,000+ present, whereas Pink-feet would number only a few hundred at best. By 2000/2001 it started to change around and numbers of Pink-feet gradually increased as the Greylags decreased. Nowadays, it would be good day if a thousand Greylags were present whereas Pink-feet commonly number 10,000-15,000-25,000+ in October/November, and a maximum of 56,000 was recorded in November 2018. The numbers at Skene fluctuate, reflecting movements between roosts here in Scotland and England throughout the winter, and also freezing and snow conditions. As Skene numbers diminish so those at Montrose Basin seem to increase, with more than 80,000 counted there recently. From only about 30,000 in the 60s, the UK total now numbers about half a million as the Icelandic population has increased year on year. Meanwhile, the migrant Greylag population has remained roughly steady but a large proportion now 'short-stop' in Orkney as mild winter conditions favour them not travelling so far to avoid harsher winter conditions in Iceland; in fact several thousand now overwinter in Iceland with increased growing of arable crops in milder winter conditions.
The Bean Goose is far rarer and being very similar in appearance to the Pink-footed Goose is very difficult to identify in the field. It too comes in two subtly-different forms, though this time from northern Europe and NW Siberia. The difference is the shape and extent of orange-pink on the beak (good luck with that!). The main distinguishing feature from Pink-feet are the bright orange legs. One or two, at the very most a few, of both species may occur in the North-East, mixed in with the commoner grey geese so a very careful look-through any flocks will be necessary to find them.
There is an often-quoted myth that the name came from a medieval belief that the goose emerged fully-formed from the Goose Barnacle, because migration patterns of birds were not known at the time and birds just seemed to appear and disappear at certain times of the year, and that no chicks were ever seen. It is certainly an ancient name with similarities in Latin, French and Gaelic, and no other origin has been suggested to my knowledge.
Finally, the Brent Goose (or Brant in the Americas) is another small goose, with a predominantly all dark back, head and neck, with just a hint of a thin white neck patch (like a choker). There are two main forms occurring in the UK, a light-bellied population from E.Canada, Greenland and Svalbard, and a dark-bellied population from Arctic Russia. Either form may occur here in the North-East, though the light-bellied is the commoner. Usually observed migrating along our coasts in large untidy flocks and stopping only briefly on coastal estuaries and bays to feed on tidal mudflats and saltmarsh. A small group has been frequenting the Ythan Estuary for a while now. They are only rarely found inland.
Good winter birding
John