The bison is one of the most romantic of all the North American big-game trophies. They conjure up visions of the frontier days and a raw western prairie challenging the settlers and ranchers for their very existence. However, bison herds declined due to changes in habitat and increased human population limiting the number of free-ranging bison to relatively small, localized herds.
Only a 1/4-inch wide, flexible steel tape may be used for length and circumference measurements on bison; a steel cable may not be substituted. At times, the horns on bison may be loose on their cores; it is permissible to remove the horns from their cores for measurement of the lengths and circumferences. Be sure to note the right and left horns as their shape is very similar.
As shown in figure 13-A, the length measurement is started by hooking the measuring tape clip-end on the lowest outside base edge on the underside of the horn to reflect the longest horn length available. The line of measurement is then maintained along the outer horn surface to a point in line with the horn tip. If the horn tip ends in a sharp point, the measured line is simply read from the tape. If the horn tip is broken or blunted, use a small carpenter’s square (or a credit card) to determine the end of the measurement line by forming a perpendicular of the square and horn axis at that point.
A mounted specimen presents a problem in location of the start of the line of measurement. Care must be exercised to begin the line at the above mentioned edge of the hollow horn. This point is often covered with hair and cape and may be fused with the mounting media. Careful probing with a penknife point, using a bright light, is often necessary to properly locate this point.
Once the proper horn lengths are established, locations of the circumference measurements are determined by dividing the longer horn length measurement into quarters. The Quarter Locations for Circumference Chart in the back of this manual provides these values. Record the values of the three quarter locations in the space provided to the right of each circumference description on the score chart so they can be easily verified if there are any questions later about the measurement. Mark the three quarter locations (D-2, D-3, and D-4) carefully on the original line of horn length measurement of each horn with a soft pencil.
Be sure to establish these quarters by measuring from each horn base to the tip. This is essential to give proper matching of quarters on both horns. If the quarters were located by measuring from the tip toward the base, the quarter locations would be placed nearer the base on the shorter horn than on the longer. This would probably make an artificial difference between the quarter measurements. When marking the quarters on the horn, be sure to hold the tape stationary along the original line followed in measuring the length of horn.
Once the quarters have been properly located and marked by pencil, and the calculations verified, measure each circumference by carefully arranging a ring-end measuring tape at a right angle to the horn axis at that point. At the zero point of the tape, the two ends should pass on opposite sides of the pencil mark, with the tape and the horn axis forming a right angle. Snug the tape around the horn before reading the result, again checking to be sure that the tape is correctly positioned on each side of the pencil mark. If you use a clip-end tape to measure circumferences, overlap the tape at a full 10 inch increment to simplify the procedure. Be sure to subtract the amount of overlap before recording the measurement. If it should happen that one horn is broken to the extent that the horn material is completely missing at the D-4 circumference location, simply enter a zero value in the appropriate column of the score chart to reflect this missing value.
Take care in making the circumference of base measurement (D-1) of a mounted specimen to avoid including hair, plastic material added by the taxidermist, or a portion of the skull in this measurement. This measurement is taken at right angles to the base of the horn, and not by following the basal edge of the horn. The basal edge of the horn is usually irregular and lies at an angle with reference to the horn axis. This makes the proper measurement of D-1 a bit tricky. Very often it is an inflated, and thus incorrect, value. The key is to make the line of measurement perpendicular to the axis of the horn base. The measured line must be on horn material throughout the measurement, not on air space. Figure 13-A demonstrates this approach.
The tip to tip measurement is simply from the center of the tip of one horn to the center of the tip of the other. Normally, it is taken by using the carpenter’s folding rule or a steel measuring tape.
Greatest spread is best taken by use of two perpendiculars, such as carpenter’s levels held upright by large c-clamps or perfectly square-cut wooden blocks. The measurement is then taken by folding carpenter’s rule between the perpendiculars. If perpendiculars are not available, a floor and wall can be used for one perpendicular, with the second being improvised from a carpenter’s level or a straight, square-cut board. In no case should the human eye be relied upon for establishment of the second perpendicular line.
Note that tip to tip spread and greatest spread are supplementary measurements and are not figured into the final score. They are recorded on the score chart as they do indicate the general conformation of the horns and, with the other measurements, help to give a more complete picture of horn formation for the trophy.
Evaluating the American bison (or buffalo as it is often commonly called) is not easy. Bison are not common enough for the average hunter to become familiar with their immense size. A good-sized bull is some six feet high at the top of the shoulder hump and will weigh about a ton on the hoof. The head is shaggy and usually with a beard reaching nearly to the ground. The huge shoulder hump adds to the effect of a really enormous animal. Thus, when confronted under field conditions with an average-sized bison, the hunter may well think it is a really big one. One therefore needs to observe enough bison to be able to tell the difference between an ordinary bull and a real trophy bull. Observation of bison at zoos, parks, or even on ranches and farms may be of great help.
One should always look at the size of the horns in comparison to the general body size of the bison. A set of large horns on a small-sized bull will appear relatively much larger than the same horns on a larger bodied bull. One needs to make sure that the trophy-sized horns apparently being offered by the bison in question are not just the illusion of large horns on a small body.
After you have looked at a number of bison, some general trends in horn development will be apparent that will aid trophy evaluation. In a young bull, the horns come out of the head and turn almost straight up. As the bull gets older, his horns will develop the characteristic gentle curve of the mature trophy, with the horn tips beginning to point toward each other. The horn bases increase considerably in size with age, whereas on a younger animal the horn will appear rather thin and nearly uniform along its length. On the mature trophy bull, the effect of the entire horn is that of a strongly tapering, half-moon curve.
As with all horned game, be sure to view both horns before making the decision to shoot. Often, one horn may be broomed or broken-off at the tip, materially lessening the score. ■
