The pronghorn has true horns consisting of a bony core surrounded by a horn sheath. They are unique in that they shed this outer horn sheath, including the triangular-shaped prong portion from which they get their name, each year in late fall or early winter. The prong may vary greatly in both size and location on the horn. It may be located close to the skull or higher than the third quarter. As prong measurements contribute significantly to the score, record-class heads will have well-developed prongs.
Only a 1/4-inch wide, flexible steel tape may be used for length and circumference measurements on pronghorn; a steel cable may not be substituted. At times the horns on pronghorn may be loose on their cores; it is permissible to remove the horns from their cores for measurement of the lengths and circumferences.
The first step in measuring pronghorns is the determination of the proper horn length measurement, which is vital to the subsequent measurements. Pronghorns show great variability in the degree of curvature and direction in which the horn tips point. In addition, the base of the horn is characteristically jagged or serrated. Therefore, the proper location for beginning the length of horn measurement is defined as the lowest outside edge of these serrations on the horn base. The outside edge of horn is defined as the area from the front center to the rear center of the base of the horn along its outer side.
As shown in figure 11-A, the start of the length of horn measurement is located with a straightedge held perpendicular to the horn axis touching the lowest point of horn on the outside edge of the horn base. Often this point of contact is not at the center of the outside edge. Since the line of measurement is taken along the center of the outer side of the horn, it will be necessary to hook the clip-end tape on the bottom of the straightedge to begin the line of measurement. The line of measurement is then maintained along the horn surface to the tip. This line is along the outer curve of horn, which will vary in specimens according to the general curvature of their horns and the direction of the horn tips. If the horn tip is sharp, simply measure to its end. If it should be noticeably blunt, 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.
Pronghorns commonly show small protuberances on the horn, occasionally developing into sizable ones. Should the length of horn measurement fall on these, simply measure across them so long as they do not noticeably affect the measurement. Should a large one inflate this measurement by pushing the measuring tape noticeably into the air, the tape should be slightly repositioned to keep the measured line close to the horn surface. Make note of any horn projections exceeding one-half inch in length that interfere with the length of horn measurement; explain how the measurement was taken in the REMARKS section, or in the blank space at the top of the score chart.
Measurement is best accomplished on unmounted trophies, since the hair grows above the horn base and necessitates the use of considerable care to locate the exact lowest edge of the serrated horn sheath for the start of the length-of-horn measurement. On a mounted specimen, the horn base 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 find the proper starting 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 at 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 easily be verified if there is any later question about the measurement. Mark the three quarter locations (D-2, D-3, and D-4) carefully on the outer side of the horn on the original line of horn length measurement with a soft pencil (figure 11-A).
Be sure to establish the quarter locations by measuring from each horn base to the tip. This is essential to get 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.
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, above the serrations and entirely on horn sheath material, and not over air space. Figure 11-B shows the proper technique.
Once the quarters have been properly located and marked with a 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 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.
The intent of the scoring system for pronghorns is that the first quarter circumference (D-2) is taken below the prong and the second quarter circumference (D-3) above the prong as figure 11-A illustrates. Therefore, should the swelling of the prong be at the marked location for a circumference measurement, simply either move the steel tape immediately below the prong for D-2 (figure 11-C) or up for D-3 (figure 11-D) to a point where the circumference can be measured without interference from the prong swelling. This avoids the artificial increase that would result if the swelling of the prong were included in the measurement.
Generally the D-3 circumference is taken above the prong. In a few, very rare cases the prong may be located so high that the D-3 quarter location falls below the prong swelling (figure 11-E). In such instances, the D-3 circumference is taken at the actual quarter location below the prong. (Note: A major difference between the Boone and Crockett records-keeping program and both the Pope and Young and Longhunter Society records-keeping programs is that the D-3 measurement below the prong is only acceptable to Boone and Crockett. The other two groups require that D-3 always be taken above the prong.)
As noted earlier, bumps or projections may occur on the lower part of the horn. These may occur at circumference locations. If they are small and occur only on one horn, any increase in the circumference measurement is adjusted by the subtraction in Column 3 for lack of symmetry. If they are sizable and occur on both horns in such a location that the circumferences of both horns are unnaturally and significantly affected, the circumference measurements should be made around them if possible. In any case where such projections exceed one half inch in height and interfere with the circumference measurements, explain how the measurement was taken in the REMARKS section, or in the blank space at the top of the score chart.
The length of prong is measured from the tip of the prong along the upper edge of the prong on the outer side of the horn to the horn proper, then continued at a right angle to the horn axis to the back edge of the horn. Figure 11-F illustrates this measurement. The back of the horn is commonly rounded, making the exact location of the end of the measurement line difficult to establish. It is determined by placing a straightedge across the backs of both horns simultaneously. A lead pencil or chalk is used to mark the spot on each horn where the straightedge and horn material contact. These marks are then the ends of the measurement lines and may not fall on the exact center of the back of the horn.
If there is a crack where the prong extends from the horn, the length of the prong should be taken passing over the entire crack. Once the initial prong length is taken, the width of the crack should be measured as illustrated in figure 11-G and deducted (Length A) from the prong’s length. The Measurer should then record the adjusted length of the prong on line E of the score chart and include a comment in the remarks box at the bottom of the score chart noting that the width of the crack was deducted from the length.
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. It may be taken directly by the use of a carpenter’s folding ruler or steel tape. It is a supplementary measurement and not figured in the final score.
The inside spread is measured at a right angle to the centerline of the skull at the widest point between the main beam of the horns. This measurement is supplementary and not included in the final score computation nor is there any deduction for excessive spread.
Once the Measurer has completed scoring a pronghorn, he should answer the question on the score chart that asks if the horn cores were loose or mounted with a bonding substance at the time of measurement. If the answer is yes, the records office will evaluate each entry on a case by case basis to determine if the horns have been artificially inflated. If so, the records office will make any necessary adjustments to the score chart.
In order to be eligible for entry, both horns, when viewed from the front, should angle upward approximately 15 degrees or more from a horizontal plane projected across both horn bases. This eliminates heads with horns that project straight out or downward from inclusion in the records.
In the past, pronghorn with skull plates that had been fractured or shattered by a bullet, dropping, etc., were not acceptable for entry in B&C. However, it is now possible to enter such trophies, so long as the pieces can be perfectly pieced back together and the spread measurements taken. Skull plates that have been sawn in half still are not eligible for entry in B&C. Each damaged skull is considered on a case by case basis. See the Shed Antlers/Split Skulls policy on page 263 for complete details of this policy.
The unique pronghorn, its population reduced to some 15,000 head in the early 1900s, is one of America’s greatest conservation success stories. Now legally hunted in nearly every western state, it has become one of our most numerous game animals, second only to deer. For the pronghorn hunter, it is also one of the most difficult animals to judge in the field. Nearly always, the first-time successful pronghorn hunter finds the horns of his buck to be much smaller than they appeared to be when he made the shot.
The current B&C scoring system was adopted in 1950 and was first reflected in the 1952 B&C records book. There were 67 total pronghorn entries listed meeting the minimum score requirement of 70 points. In contrast, the latest 1999 book lists 1,443 entries with a score of 82 or more. Only 21 achieved that score in the 1952 book.
A pronghorn with heavy 14-inch horns and four-inch prongs will score about 70 points and is a trophy no one need be ashamed of. If, however, a trophy qualifying for the current B&C all-time records minimum of 82 is the hunter’s goal, a buck with 15 to 16 inch horns, 6 to 7 inch bases, and 5 to 6 inch prongs must be found.
When guiding and hunting for pronghorn in several states over the past 36 years, I have used the following methods of evaluating the most critical features of trophy heads. Hunters who have attended the pronghorn hunting seminars where I have recommended these methods say they have worked well for them also.
Horns should appear to be much longer than the length of the pronghorn’s head, measured from base of the ear to tip of nose. This distance averages around 13 inches. Also check the horns against ear length. If the horns appear to be 2-1/2 to 3 times the ear length, which averages 6 inches, they are probably long enough. Remember, horns that have pronounced, rounded curves inward with horn tips ending in downward hooks, may be half again as long as they appear to be, while straight horns with little hooks at the very tips will not yield much of a bonus.
The prongs of most record-class buck will appear extremely large and will project from the horn at or above the level of the ear tips. Prongs are measured to the rear edge of the horn they project from, so a 6-inch prong will appear to extend about four inches from a heavy horn — or twice the width of the horn viewed from the side. A head with very high prongs may cause the third quarter circumference measurement to be taken below the prong instead of above it, which usually helps the score.
As four circumference measurements are taken on each horn, it is obvious that heavy horns are a must for record-book pronghorn. The eyes of a pronghorn are located directly below the horn base, so they are a convenient feature to judge horn mass. As viewed from the side, the horn base should appear to be twice the width of the eye, which generally measures a little over 2 inches. This equates to horn base that measures 6 to 7 inches in circumference.
Pronghorn are usually found in open country and have exceptional vision. Therefore, good binoculars and a spotting scope are necessary to evaluate potential trophies at the distances required to avoid spooking them. Good optics and careful use of them will save the hunter many needless stalks when searching for a record-class buck.
A major factor in pronghorn trophy quality is seasonal weather. While not directly related to field evaluation, it may be a factor in where you choose to hunt. Pronghorn shed their outer horn sheaths in the fall, leaving a bony core upon which regrowth of horn material soon begins. A mild winter coupled with a warm, wet spring, and early summer providing abundant feed can result in much larger horns than will a severe winter and drought conditions the next summer. ■
