TETRAD, in natural history, a genus of birds of the order Gallinx. Generic cha racter : near each eye a spot, which is na ked, or papillous, or slightly covered with feathers. Birds of this genus, which, according to Gmelin, comprehends the grouse, the partridge, and the quail, fol low the dam immediately on being hatch ed, and before the shell is wholly detach ed from them ; their bill is strong and convex, and their flesh and eggs form an exquisite repast. There are seventy three species, of which the following are best deserving of notice.
urogallus, or the cock of the wood, is of the size of a turkey, and is found from Russia to Italy, preferring the ele vated and mountainous parts of temper ate countries, as it delights in a cold tem perature. Its eggs are deposited on moss, and whenever left by the female, who is unassisted in the process of incubation, are covered over with leaves. The males and females live separate, except during the months of February and March. Their food consists of various plants and grains, and of buds of trees. The seeds of the pine and fir they are particularly fond of The sound of the male resem bles not a little the whetting of a scythe. These birds are in high request for the table, and are sometimes sent from Pe tersburg to London, in a very rigorous winter, arriving, it is said, in good condi tion.
T. tetrix, or the black grouse, is larger than a common fowl, and abounds in the British islands, particularly in the north ern districts. In winter these birds shel ter themselves in low, situations. On the return of spring they withdraw to the mountains, and contests occur between the males, which are carried on with ex treme violence and fury, and during which they are so agitated by rage, that they may be approached without obser vation, and knocked down with a club. The birds of this species, and of the last, do not pair like other birds, and the mate is generally seen with several females in his train. They subsist on seeds and her bage, and are particularly fond of the seeds of the birch and Siberian poplar.
T. Canadensis, or the spotted grouse, is thirteen inches long, abounds in the neighbourhood of Hudson's Bay, and feeds upon juniper berries, and the cones of spruce. These birds are eaten by the natives, both in summer and winter, dur ing the latter season being hung up by the bill, and preserved by the frost. They are extremely stupid, and will scarcely make an efFort to evade; danger.
T. lagopus, or the ptarmigan grouse, is fourteen inches long, and inhabits the north of Europe. It is not uncommon in the Orkneys and the Hebrides, and is sometimes found in Cumberland. These birds subsist on seeds, fruits, and berries, and are, like the last, silly and inadvertent to danger.
T. perdix, or the European partridge, is thirteen inches long,' and abounds in the temperate regions of Europe. It is unable to sustain rigorous cold, or intense heat. It feeds on green corn and other
plants, and almost every species of grain ; but the eggs of ants constitute its favour ite food, and are almost essential for the nourishment and preservation of the young ones. Experiments have been re peatedly, but ineffectually, made, to in duce the breeding of this bird in con finement; its eggs, however, are fre quently introduced into the nest of a common hen, and are thus matured, and the young are treated affectionately by that bird, and may be brought to per fection, if provided with their appropriate food. The attachment of the male and female partridge to their offspring, is highly interesting. They both sit cover ing them frequently at the same time and, when danger approaches, will ex pose themselves to its direct attack, in order to decoy the attention of the ene my from those whose security they pre fer even to their own existence. They pair early, build with dry leaves upon the ground, and the young run after their parent as soon as they are extricated from the shell. They breed in England only once a year, and live to the age of twelve years. They are highly valued for food.
T. coturnix, or the quail, is between seven and eight inches long, and inha bits almost every country of the old world, but is not found in America. It is mi gratory, and moves in spring towards the colder climates, returning southerly in autumn. In these progresses quails fly in immense multitudes, and are, taken in the islands of the Archipelago in such numbers as for a short time to be the principal article of food for the inhabit ants, and to constitute an important source of income and revenue. Within a few miles along the coasts of Italy, a hundred thousand are said to have been taken in a single day. Latham informs us, that they used to be an article of impor tation from France to England, in cages formed with several divisions, and con taining about a score of birds in each, and that he had often seen these cages filled, with them, and attached to the stage coaches between Paris and London. They breed, however, in that country, and though many,rnigrase beyond the isl and, many only change their residence within it, on the approach of winter, from the more exposed to the more sheltered parts. These birds were pro verbial among the Romans for captious ness and quarrelling, and are employed among the Chinese for the same amuse ment as game cocks in E•gland. They were so used, indeed, likewise among the ancients. It appears highly probable that the extraordinary supplies of the Israelites were derived from this species of birds in their vast flights to and from Africa; and though represented in Jewish history as a permanent supply, this cir cumstance may easily be accounted for, from the exaggerating and superlative phraseology which characterizes all ori ental description.