British Museum (Natural History) General Guide

by British Museum

In the corresponding case on the left are further illustrations of the same subject. A pair of red Jungle Fowl (Gallus bankiva, or G. ferrugineus) of India represents the species from which the breeds of Domesticated Fowls are generally considered to have been derived. As examples of extreme modifications in opposite directions produced by selection, are exhibited the Japanese Long-tailed Fowls, in which some of the feathers (tail-coverts) attain a length of nine feet, and specimens of a breed in which the tail is absent. There is also shown a group of Fowls living wild in the woods of the Fiji Islands, which are descendants from domesticated birds introduced in the eighteenth century. A pair of Cochin Fowls is exhibited in the same case to display development in point of size and in the abundance of feathers on the limbs; while a pair of white “Silkies” illustrates a modification of the plumage, accompanied by a rudimentary condition of the tail-feathers. The pair of Coloured Dorkings exemplifies a breed cultivated in England.

A series of Canaries is shown in a case in the archway leading from the east side of the central hall to the north hall, as an example of a late addition to domesticated animals, these birds having been first imported into Europe from the Canary Islands in the early part of the sixteenth century. Specimens are exhibited of the wild birds, and of some of the modifications produced by selection.

Ruffs and Reeves, illustrating Changes of Plumage according to Sex and Season.

A case placed to the north of the one containing Fowls illustrates a remarkable instance of external differences in the two sexes and changes in plumage at different seasons, not under the influence of domestication. The birds in it belong to one species, the Ruff (Pavoncella, or Machetes, pugnax), of which the female is called Reeve; a member of the Plover family (Charadriidæ). In the upper division of the case are shown the eggs, newly-hatched young, and young males and females in the first autumn plumage; as well as adult males and females in winter, when both sexes are exactly alike in colour and distinguishable externally by size alone. The large group occupying the lower part of this case consists of adult birds in the plumage assumed in the breeding time (May and June). In the female the only alteration from the winter state is a darker and richer colouring, but in the males there is a special growth of elongated feathers about the head and neck, constituting the “ruff” from which the bird derives its name. In addition to this peculiarity, another, rare among wild animals, may be observed, namely, striking diversity of colour in different individuals. Of the twenty-three specimens shown no two are entirely alike.

Wild Ducks illustrating Seasonal Change of Plumage.

Next in order stands a case displaying the variations, according to season and age, in the plumage of the Wild Duck, or Mallard (Anas boscas). The most noticeable feature in the plumage-changes is the assumption in summer by males of an “eclipse-plumage,” resembling the one worn by females at all seasons. At other times the males are more brilliantly coloured than their partners. The eclipse-plumage corresponds to the winter, or non-breeding, dress of other birds which have a seasonal change.

Adaptation of Colour to surrounding Conditions.

On the same side of the hall follow two cases illustrating the adaptation of the colour of animals to their natural surroundings, by means of which they are rendered less conspicuous to their enemies or their prey. The first contains a specimen of a Mountain or Variable Hare (the common species of the north of Europe), a Stoat, and a Weasel, together with some Willow-Grouse and Ptarmigan, as well as an Arctic Fox, in their summer dresses. All were obtained in Norway, and show the general harmony of their colouring at this season with that of the rocks and plants among which they live. The second case displays examples of the same animals obtained from the same country in winter, when the ground was covered with snow. Such striking changes as these only occur in latitudes and localities where the differences between the general external conditions in the different seasons are extreme, where the snow disappears in summer and remains on the ground during most of the winter. Even some of the species here shown do not habitually turn white in the less severe winters of their southern range, as the Stoat in England and the Variable Hare in Ireland. A few permanent inhabitants of still more northern regions, where the snow remains throughout the year, such as the Polar Bear, Alaskan Bighorn Sheep, Greenland Falcon, and Snowy Owl, retain the white dress throughout the year. The whiteness of these animals must not be confounded with albinism, or whiteness occurring in individuals of species normally of a different colour, which is illustrated in a case on the other side of the hall.

Protective Resemblance of Desert Animals to their Surroundings.

The case on the east side of the hall nearest the great staircase contains examples of conformity of general style of colouring to surrounding conditions, as exemplified by some of the commoner Birds, Mammals, and Reptiles of the Egyptian desert, placed on the stones and sand amid which they habitually dwell. The advantage of this colouring in concealing the herbivorous species from their enemies, and in enabling the carnivorous to approach their prey unperceived, is obvious. Many excellent cases of concealment by adaptation to surroundings, especially in eggs and young Birds, may be seen among the groups in the Bird-gallery.