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Show 316 CANIS LATRANS. The Coyote, or Prairie Wolf, the nearest American affine ef the Gray Wolf, is as remarkable for its constancy of character, especially in respect to color, as the latter is for its variability. The individual variations in the color of Canis latrans consist generally in the depth or intensity of the shadings of black or rnfous that more or less pervade the pelage of certain parts of the head and body. Although considerable variations have been noticed in respect to the form of the skull, they are small in proportion to those presented by Canis lupus. It is also much less influenced apparently by locality. The species has, however, a less extended range than Canis lupus, and the specimens at command represent localities less widely separated than do the series of skulls of Canis lupus. Measurements of forty skulls are given below, mainly from Nebraska. Dakota, and Wyoming. The most distant localities are Columbia Eiver and Fort Tejon, California, Southern Texas, and Fort Union. Montana. Of this series of forty skulls, the average is 7.40; only two attain a length of 8.00, one of which ( measuring 8.00 in length) is from Fort Union, and the other ( 8.05 inches in length) is from Fort Massachusetts, New Mexico. Only two fall below 6.95, one of which measures 6.65 and the other 6.50; the smaller being from the Coppermine Eiver, New Mexico, and the other from Fort Randall, Dakota. Of thirteen specimens from Fort Randall, the largest measures 7.60 in length and the smallest 6.65, the majority ( more than three- fourths) falling between 7.00 and 7.50, thus presenting a remarkable uniformity in size. Ten others from Fort Kearney average ftilly as large, the extremes being 6.95 and 7.60, while four- fifths of them fall between 7.00 and 7.50. Three specimens from Fort Tejon, California, measure respectively 7.95, 7.60, and 7.45, or above the average of those from Dakota and Nebraska! Four specimens from Wyoming Territory, however, measure each 7.80. A single San Diego specimen measures 7.75, and two specimens from Southern Texas respectively 6.95 and 7.00, or bat little below the average of northern specimens. Of four specimens from New Mexico, three attain or exceed 7.40, one reaching 8.05 and forming the largest of the series; the other, with a length of only 6.50, forms the smallest of the series, both the largest and the smallest being from New Mexico. It thus appears that in Canis latrans there is comparatively little decrease in size southward, instead of the southern averaging fully 25 per cent, smaller, as is the case in Canis lupus. The difference between the extremes is only 1.55, or about 20 per cent., against twice that amount in Canis lupus. Throwing out the two skulls that fall below 6.95 would reduce the difference between the extremes to 1.10, and the variation to only 15 per cent, of the average! In both Canis latrans and Canis lupus, the width of the skull averages about one- half the length, ranging in Canis latrans from 0.49 to 0.52, while in Canis lupus the range in this proportion is from 0.48 to 0.56. A glance at the table shows that while the Upper Missouri specimens are rather younger than those from Fort Kearney, they rather exceed them in size, and the difference would be somewhat greater if they were of strictly corresponding ages. The single very large skull from yew- Mexico is also that of a very old individual. |
