Basin Notes - October 2011

Swans a'plenty

Now that the pink-footed geese are established on the Basin it is time to keep a look-out for another of our winter visitors from Iceland.

Over the next few weeks we should see increasing numbers of whooper swans gathering towards the west end of the Basin and in local fields. During most winters a small flock remains in the immediate area, but they also can be found scattered around the countryside often in family groups.

Whooper swans have a bright yellow bill with a black tip whereas our resident mute swans have a bill coloured between red and orange. When swimming, the whooper swans also tend to hold their necks much straighter than the mute swan.

As the name implies, whooper swans have a loud, bugling call easily distinguished from the call of the geese.

Anyone who has strayed too close to a mute swan nest will be well aware that the species name is a misnomer. They are capable of aggressive calls and hissing sounds when they feel threatened and they have a range of other calls to maintain contact. The distinctive noise of their wing beats also serve as a contact call. None of the noises however are as loud as the bugling of a whooper swan.

The phrase 'swan song' is based on an enduring myth that the mute swan, supposedly silent throughout its life, produces a beautiful song just before its death. The myth first appears in classical Greek plays and endures in the work of Chaucer and of Shakespeare, even though both will probably have been aware that there was no truth in the legend. There is even a musical reference in the work of Sibelius, which adds weight to the argument that you should never let facts get in the way of a good story.

If you are very lucky, when looking for whooper swans you might come upon a tundra swan. This species breeds in Siberia and is a much less common winter visitor than the whooper swan. We have local sightings most winters, and they can be distinguished from the whooper swan by the fact that they are smaller and have less yellow on their bill than the whooper swan.

During the 1960s, the naturalist and painter Sir Peter Scott produced accurate illustrations of the heads and bills of the tundra swans at his property at Slimbridge in Gloucestershire.

He quickly realised that each bird had a unique pattern of yellow and black on the bill and he was able to recognise every individual within the flock.

In Britain, the tundra swan is much more commonly known as the Bewick's swan. Thomas Bewick was a printer and engraver who first published his History of British Birds in 1804. This is now widely recognised as the first field guide for aspiring ornithologists and is deservedly famous for the quality of Bewick's woodcut illustrations which depict scenes of rural life as well as the bird species.

If you consult Bewick's book you will find that he refers only to wild swans and mute swans, and there is no mention of the species which now bears his name. During his lifetime nobody had established that there were two species of 'wild swan' wintering in the UK, nor did they know that one species bred in Siberia and the other in Iceland. The tundra swan was first identified as separate from the whooper swan in Bewick's native Northumberland in 1830, two years after his death, and it was named in honour of the contribution he had made to ornithology.