The Shetland Pony

by Charles Douglas; A. I. Douglas

But while in tropical islands the relative proportion of the various parts of pigmy horses may be maintained, in islands near the Arctic Circle dwarfing may imply undue shortening of the limbs, and that certain parts of the limb are more reduced than others.

A striking instance of unequal reduction we have in the Udganger or Nordlands ponies, once common in Bodo, a small island within the Arctic Circle off the coast of Norway. Fig. 2 shows that the limbs of the Bodo ponies were relatively nearly as much dwarfed as in a dachshund, while fig. 3 shows that Iceland ponies of the Nordlands type may closely agree in conformation with Exmoor and other well-built ponies of the Celtic race.

Very little is known about the make and size of the horses which first reached Shetland. The evidence as far as it goes indicates that they belonged to small varieties measuring from 11 to 12 hands at the withers. If horses were introduced from Norway during the Norse occupation, the majority of them would in all probability belong to the Nordlands race—i.e., the race from which the modern fjordhest is believed to have mainly sprung. Probably unequal dwarfing more or less pronounced took place at a comparatively early period in some of the smaller islands, while in the more fertile parts of the main island, and in the rich island of Fetlar, the reduction in size (as in Java ponies) would be nearly uniform. It is conceivable that some of the unimproved ponies now living in Shetland, and also some of the improved ponies bred and reared far from their ancestral island home, are as well proportioned as members of the Exmoor or Welsh breeds. One must, however, be prepared to find that not a few of the inbred pedigree ponies have undergone unequal dwarfing, one part of the limbs, as in the dachshund, having undergone more reduction than the adjacent parts.

Dwarfing in Shetland Ponies of the Celtic or Riding Type.—That well-proportioned Shetland ponies of the riding or Celtic type still exist is suggested by the measurements of Pamela and certain other fine-limbed pedigree ponies. Pamela (40 inches at the withers, 25 inches from elbow to ground, and 5·25 inches below the knee), in the form and length of the head, length of the limbs and their relation to the height at the withers, very closely agrees with the 41-inch Java pony.

The skeletons of Shetland ponies of the riding type available for study (viz., of Highland Chieftain, Egil, and Eric) also indicate that in a considerable number of cases the dwarfing is uniform. Though in many Shetland ponies the distance between the knees and the fetlocks looks very short, the front cannon-bones may be relatively as long as in thoroughbred race-horses. In Highland Chieftain[F1] (fig. 4) the front cannon-bones (metacarpals) are 136 mm. long and 20 mm. wide at the middle of the shaft; in Persimmon,[F2] the famous thoroughbred 16·2 race-horse (fig. 5), the metacarpals measure 276 mm. by 38 mm. As Highland Chieftain measured 33 inches, and has cannon-bones measuring 136 mm., he was half the height of Persimmon, and has cannon-bones practically half the length. In Highland Chieftain the cannon-bones (fig. 4) are not only relatively as long as in Persimmon (fig. 5), they bear almost exactly the same relation to the bones of the forearm and arm as in Persimmon—the radius (chief forearm bone) being relatively only 8 mm. shorter, the humerus (upper arm bone) relatively only 10 mm. longer. Nevertheless the cannon-bones of Highland Chieftain are relatively shorter than in typical Celtic ponies. In a 33-inch Shetland built on Celtic lines the cannon-bones should measure 142 mm., hence it may be assumed the cannon-bones of Highland Chieftain have been dwarfed to the extent of 6 mm. or one-quarter of an inch.

[F1] The skeleton of Highland Chieftain (a 33-inch Shetland pony bred in Scotland) is in the American Museum of Natural History, New York; Egil’s is in the University of Edinburgh.

[F2] The skeleton of Persimmon is in the British Museum.

The only striking difference between Highland Chieftain and a typical 12-hands Celtic pony is in the face. In modern horses, while the form of the cranium or brain-box is nearly constant, the face varies both in size and in its relation to the cranium. In the wild steppe horse (Equus przewalskii) of Mongolia, which during part of the year subsists on hard dry food, the jaws are so long that the length of the face (fig. 8) is twice the width across the orbits, thus giving a frontal index of 50; whereas in a broad-browed Iceland or Highland pony the face may be only 1·6 times the width, which implies a frontal index of 60. In the Celtic race (to which Highland Chieftain mainly belongs) the normal frontal index is 54—i.e., the length of the face is 1·8 times the width—but, as in Highland Chieftain, the length of the face is only 1·5 times the width, the frontal index[F3] is as high as 65. Further, in Highland Chieftain the profile instead of being convex as in steppe horses (fig. 8), or nearly straight as in many Exmoor ponies, was decidedly concave or dished (fig. 4). The difference between the profile of a Shetland pony and that of a steppe horse is brought out by figs. 6 and 8.

[F3] The frontal index is obtained by multiplying the greatest width above the orbits by 100, and dividing the result by the length of the face, as measured from the alveolar point to a line connecting the supra-orbital foramina.