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WILDLIFE OF NORTHERN ENGLAND

Anatidae-3 -Swans

This is the final part of a triology of articles considering the family of birds known as Anatidae, the first-Ducks, the second-Geese and here now the Swans. Swans are placed in the genus Cygnus. Cygnus is a genus of web footed birds which are found on rivers and canals and small lakes rather than on the sea or larger lakes. When they do appear on larger lakes they always tend to be near the shore and never on the the expanse of broad waters.

The chief reason is that they are vegetation feeders and although their long necks enable to reach the bottom to a depth of a metre or so, they never dive and they rarely feed upon the land { in their natural habitat} or in any other mode other than floating on the surface of the water. They are among the most ornamental of all water birds on account of their size, their graceful form and motions and in most species the snowy whiteness of their plumage which are most familiar with. 

Tundra swan--

Photograph courtesy of J&K Hollingsworth

The leading characteristics of swans

The bill is as wide at the tip as it is at the basal part. the nostrils are pierced about the middle of the length of the bill and the neck is very long compared to any other web-footed birds. Swans feed upon roots, seeds, and various parts of plants which are blanched and succulent by being under water.

They are to an extent social birds and where there is sufficient scope and they are not disturbed, they are found in troops, more or less numerous according to circumstances. In the breeding season they are strictly monogamous, and the pairs take up their nesting grounds at some distance from each other.

Swans are hardy and very long lived birds, and their down, or, under plumage, is so close and fine that they are well adapted for remaining on water for the greater part of their time. There are six swans in the genus Cygnus. they are the Trumpeter swan { America} The Black swan {Australia} Black necked swan { South America}, Whooper swan, Bewick's swan and the Mute swan. In this article we review the latter-the Mute swan a bird familiar to everyone here in the UK.

Mute swan photograph courtesy of Amanda Boyd {USFWS}

The Mute swan,Cygnus olor

The mute swan is a resident breeder which is 152 cm long with a wing span of 223 cm. The male weighs 11.5 kg the female 9 kg.

The body is rather thicker in proportion to the length, and is on average an heavier bird than the Whooper swan. The bill is of an orangey-pink colour with margins and the basal cere black, which swells into a tubercle of considerable size.

The whole plumage of the mature bird, when on water, in a pure atmosphere, is beautifully white. Their are few things designed by nature that are more beautiful than mute swans, especially when they are on small expanses of clear water, which occur in many of the rich little valleys in the UK. Though a majestic creature on water both in appearance and motion, the appearance of the swan harmonises best with clear and tranquil water, and grasses and green meadows greatly enhance the effect. 

Photograph courtesy of Ryan Haggerty.

In places they frequent they soon become very familiar and almost tame in their demeanour. they have little to fear from enemies and are quite friendly , at least for the greater part of the year. However, when the have nests, they do not only defend them with great bravery, but attack in the most resolute manner any animal that approaches to near and that includes humans.

Breeding and young.

The swan nests at the edge of the water, selecting a small islet if possible. This is to aid defending of the nest, which is constructed of a huge pile of reeds and twigs, or any similar material that is available to them. The birds never seem to think they have enough material and are constantly adding material to it. Both birds undertake the task. This constant adding of material has in fact helped the birds to save their eggs being swamped during floods caused by prolonged and heavy rain.

The eggs , the largest laid by any British bird, are of a pale grey green or whitish with a rough shell. They vary in number according to the age of the female producing them. A Young Pen { female}  may only produce 3 eggs or so , while the number increases with age, till the bird produces 5-7 eggs some times even more. The eggs may first be encountered April or May.

The female is a close sitter during incubation, a process that takes 34-35 days. The Cob {male} is very assiduous in watching for the safety of his family. He is ready to resist even those of his own species. They raise just one brood per year. The cygnets are grey and do not acquire their full plumage until the second year and until then they usually keep in company of their parents until the breeding season once again comes around and they are forced to disperse. Whilst in this juvenile garb the cygnets have very little of the majestic appearance of the adults.

 

Photograph by Dal.

No birds are more, or indeed so much at home on the surface of the water as swans. Their size and closeness, and at the same time, tightness of the plumage, enable them to ride out during gales, in which few other birds can keep the surface. The pure whiteness of their colour, together with the abundance and fineness of their down, render them very independent of changes of temperature.

When in the water they are tolerable safe from annoyance. However, a threat is exposed by way of fishing line. Discarded fishing line can become entangled in the birds beak, feathers and feet causing distress to birds. 

Conservation Issues--2012

Mute swans in the UK are on the Green List of Conservation Concern-there are no current concerns.

The long term trend for England seems to be a rapid increase. The population size for Britain was estimated to be 28,000-30,000 adults in 1990.

Mute swan populations which have been fairly stable since the 1960s increased progressively from the mid-1980s to 2000. After a spell on the Amber list , unconnected with the UK trend the species was placed back on the Green List.

There has been a moderate increase in Europe since 1980 where they have a secure status.

Mute swans are widely distributed throughout the UK and Ireland. Typical lifespan is around ten years. The Irish name for the bird is Eala Bhalbh, The Welsh name is Alarch Dof.

According to the Irish Wetland Bird Survey, the largest wintering numbers {250-2000} birds are found at Loughs Neagh,and Beg and Lough Erne in Northern Ireland; Lough Ennell, the Shannon Callows and River Slaney in winter.

                                Above information courtesy of the BTO.

July, 2012---Swan Upping Cancelled for the first time in 900 years.---Swan Upping  {counting and monitoring the birds on the River Thames } has been a tradition since the 12th century. It takes place annually in the third week of July.  However, this year the event had to be cancelled due to high and dangerous water levels due to the record breaking amounts of rain the country has been subjected to this year. 

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