SQUIRREL (Fr. écureuil), properly the name of the well-known red, bushy-tailed British arboreal mammal, Sciurus vulgaris, typifying the genus Sciurus and the family Sciuridae, but in a wider sense embracing all the rodents included in this and a few nearly allied genera. For the characteristics of the family Sciuridae and the different squirrel-like genera by which it is represented, see Rodentia.
What may be called typical, that is to say arboreal, squirrels are found throughout the greater part of the tropical and temperate regions of both hemispheres, although they are absent both from Madagascar and Australasia. The species are both largest and most numerous in the tropics, and reach their greatest development in the Malay countries. Squirrels vary in size from animals no larger than a mouse, such as Nannosciurus soricinus of Borneo, or N. minutus of West Africa, to others as large as a cat, such as the black and yellow Ratufa bicolor of Burma and the Malay area. The larger species, as might be expected from their heavier build, are somewhat less strictly arboreal in their habits than the smaller ones. The common squirrel, whose habits are too well known to need special description, ranges over the whole of Europe and Northern Asia, from Ireland to Japan, and from Lapland to North Italy; but specimens from different parts of this wide range differ so much in colour as to constitute distinct races. Thus, while the squirrels of north and west Europe are of the bright red colour of the British animal, those of the mountainous regions of southern Europe are of a deep blackish grey; while those from Siberia are a clear pale grey colour, with scarcely a tinge of rufous. There is also a great seasonal change in appearance and colour in this squirrel, owing to the ears losing their tufts of hair and to the bleaching of the tail. The pairing time of the squirrel is from February to April; and after a period of gestation of about thirty days the female brings forth from three to nine young. In addition to all sorts of vegetables and fruits, the squirrel is exceedingly fond of animal food, greedily devouring mice, small birds and eggs. The squirrels of the typical genus Sciurus are unknown in Africa south of the Sahara, but otherwise have a distribution co-extensive with the rest of the family.
The Burmese Red-bellied Squirrel (Sciurus pygerythrus).
Although the English squirrel is a beautiful little animal, it is surpassed by many of the tropical members of the group, and especially by those of the Malay countries, where nearly all the species are brilliantly marked, and many are ornamented with variously coloured longitudinal stripes along their bodies. Every one who has visited India is familiar with the pretty little striped palm-squirrel, which is to a considerable extent a partially domesticated animal, or, rather, an animal which has taken to quarter itself in the immediate neighbourhood of human habitations. It has been generally supposed that there is only one palm-squirrel throughout India, but there are really two distinct types, each with local modifications. The first or typical palm-squirrel, Funambulus palmarum, inhabits Madras, has but three light stripes on the back, and shows a rufous band on the under-side of the base of the tail. In Pennant's palm-squirrel, F. pennanti, on the other hand, there is a pair of faint additional lateral white stripes, making five in all, and the under-surface of the tail is uniformly whitish olive. As this species has been obtained in Surat and the Punjab, it is believed to be the northern type. One Oriental species (Sciurus caniceps) presents almost the only known instance among mammals of the assumption during the breeding season of a distinctly ornamental coat, corresponding to the breeding plumage of birds. For the greater part of the year the animal is of a uniform grey colour, but about December its back becomes a brilliant orange-yellow, which lasts until about March, when it is again replaced by grey. The squirrel shown in the illustration is a native of Burma and Tenasserim, and is closely allied to S. caniceps, but goes through no seasonal change of colour. Another Burmese squirrel, S. haringtoni, differs as regards colour in a remarkable manner from all other known members of the group. It is a medium-sized species of a pale creamy buff colour above, lighter beneath, and with a whitish tail, while it is further characterized by the absence of the first upper premolar, which shows that it is not an albino or pale variety. Two examples were obtained by Captain H. H. Harington, of one of the Punjabi regiments, on the Upper Chindwin river. It may be added that generic subdivisions of the squirrels are based mainly on the characters of the skull and teeth. That they are essential is evident from the circumstance that the African spiny squirrels Xerus (see Spiny Squirrel) come between Sciurus and some of the other African genera. (R. L.*)