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WILDLIFE OF NORTHERN ENGLAND

Teaching Children about nature-2  a look at the characteristics of common British birds. 

This is the second in a series of pages aimed at getting children to gain a better understanding of nature. I hope it will inspire teachers to use it for that purpose.

The Hawfinch has the largest beak of the this group of birds

Photograph courtesy of Slawomir Staszczuk @photoss.net

A look at Perching Birds-Bill { beaks and plumage}

 

The most familiar garden and town birds belong to the large order-Passerine {perching birds} which includes more than half of all species of birds. {over 5000 species the world}

This vast Passerine assemblage can be divided into many groups and the birds that form the 'finch like birds' form a large group. Belonging to this group is the sparrows. The main characteristics of this group are the conical-shaped bill {beak}, the sheath is hard and strong. Such a bill has evolved for the purpose of  picking up and crushing seeds. If this large group of birds are studied a surprising number of ranges and sizes of the bill would be revealed.

The Hawfinch { see photograph above} for example possesses the largest and most powerful of them all. 

The most striking features of the male house sparrow are the black bib and the rich mottling of chestnut browns and blacks on the upper parts. However, the crown of the head is grey surrounded on each side with brown, while across the wings is a white bar.  The female house sparrow has a duller plumage and lacks the bib. The tree sparrow on the other hand, the plumage of the two sexes are identical, thus they are indistinguishable externally. they can be readily told from the house sparrow by the crown which is wholly chestnut brown, the black patch by the side of the neck and by them having a double white wing bar. 

Top---female house sparrow.  Middle male House sparrow note the grey crown of the head. Bottom-tree sparrow , note the chestnut brown crown of the head.

Photographs Top and Middle Dal. Bottom tree sparrow courtesy of Andreas Trepte www.phot-natur.de

Why then is there a marked difference in colour of the sexes of birds so closely related? 

The house sparrow has always been associated with the dwellings of man and is never far away from mans activities.the tree sparrow on the other hand seems to avoids the dwellings of man and his society, frequenting willows and other trees especially those near to streams. The tree sparrow is very local and has suffered great losses in population number over the last 40 years or so.

Now we turn to the blackbird and song thrush. Both these species are essentially animal eaters, such as worms, slugs  and snails.They will also take fruit, when it is available to them, and feed on these with great relish, often in large numbers, joined by other species of the thrush family.

The plumage of the song thrush is shared by both sexes and the young birds. In the blackbird the two sexes differ and to a certain extent so do the juveniles. The male blackbird as its common name suggests has a black plumage with a golden yellow beak, while the female has a dark brown plumage with a horned coloured beak. The juveniles resemble the female, however, the the throat and breast are spotted darker brown and the back is streaked.

Both the song thrush and the blackbird are with us all through the year, although a certain amount of migration does occur. There are certain periods of the year when they may not be seen in their usual haunts. depending on prevailing weather this period extends from October to January.  However, blackbirds and thrushes arrive from the continent during this period and may well take their place,and are impossible to distinguish them from the absent birds.

Both song thrush and blackbirds are renouned singers and here again they differ from the song-less sparrow. 

A look at the shape of birds

When one considers the characteristics of birds the shape is an easily observable one. The shape of birds as with all creatures is determined to a large degree by their lifestyle. One or two striking illustrations can be found among British birds. The swallow and the unrelated swift are in general appearance very similar. this is because they both obtain their food on the wing, therefore they both have the same requirements, powerful wings and great speed.

Owls resemble the hawks, and in time gone by naturalists classed the owls as the 'nocturnal' birds of prey and the hawks and eagles as 'diurnal' birds of prey. 

Another characteristic of the birds are the way they carry their legs in flight. The perching birds alone carry their legs close to the abdomen. Species such as the heron and the gulls hold their feet stretched out under the tail, and the short legged species, the puffin is a good example of such birds, that stick their feet out on each side.

The way they carry their neck also differs among species. The heron for example holds its neck in an S shaped position during flight so that the head touches the back, while others, geese,ducks,swans and bittern it is carried at full stretch.

Ducks carry their necks at full stretch while in flight. Below the heron just taking off. Note the feet are carried stretched out beneath the tail. when the heron is in full flight the neck is carried in an S -shape.

Photographs courtesy of the USFWS

Plumage change

Finally in this review we briefly touch upon the change of plumage many birds undertake during the breeding season, especially by the males. Most people are aware of this fact. However, the way this plumage change occurs is not as commonly known outside ornithologist circles.

Once again the house sparrow may be used to illustrate one method of change. As previously mentioned, in the spring, the male develops a conspicuous black throat referred to as a bib and the plumage in general is fresh looking , more vibrant, than the plumage which is seen in autumn and winter.This change occurs through the feather tips. If one was to examine the sparrows plumage after the autumn moult, the throat feathers will be found to be black with the exception of the tips which are a greyish white colour. the feathers of the head and upper parts in general have tawny fringes. as the winter progresses these fringes wear away, so that the time that spring arrives the stronger coloured portions of the plumage is exposed. The red breast of the linnet is acquired in the same way. 

Conversely it should be pointed out, that many species of birds display a much brighter plumage during the breeding season than in the winter months. While some birds attain the plumage of the adult birds by the end of the first year, or sooner, many take much longer to attain the adult plumage. Black backed gulls are an example that may be used to illustrate the point. the juveniles of this species make take three or even more years before they achieve the adult plumage. Until then they are adorned with a mottled grey brown plumage.

 In the next in this series  we review the food and feeding methods of British birds.

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