Saturday, June 23, 2012

How to Field Judge Desert Bighorn Sheep Part 1

Field Judging and Scoring Desert Sheep

This blog post is designed to show how to score a sheep.  There are 8 mass measurements total between both horns (4 mass measurements per horn), then you add the length of each horn add all the numbers up and that gives you the rams gross score.  The way you figure out where to take the mass measurements is to measure each horn and then divide the longer horn by four.  For example if the left horn is 35 6/8 inches long and the right horn is 36 inches long, you would divide the longer horn in this case 36 by 4 and that would give you your D1-D4 measurements.  So the base would be at 0, D2 at 9", D3 at 18" and D4 at 27 inches.  Remember that it is very important to be exact with these calculations because being off by a couple of eighths can make a dramatic difference in the rams score.  Then to find the rams Net score you subtract only the differences in horn circumference per measurement.  For example, if Left D1 is 15 and right D1 is 14 6/8 then you would have to subtract 2/8" from the gross score.  Once you subtract the differences between D1-D4 between each horn that will give you the rams Net score.  Remember that you do not subtract the horn length differences only the mass differences.
This picture is taken from the Boone and Crockett Website, it shows the side angle view of where the circumference measurements are taken from.  D1 is the base measurement of the sheep, D2 is the first quarter, D3 is the second quarter, D4 is the third quarter measurement.  Divide Measurement C of the longer horn by four. Starting at the base, mark both horns at these quarters (even though the other horn is shorter) and measure the circumferences at these marks, with measurements taken at right angles to the horn axis.

C is showing where the length of the horn is taken from.  B depicts the tip too tip spread which has no relevance in relationship to the scoring of the sheep but is just a reference measurement

This shows how the length of the horn is measured to the tip because a lot of times the tip of the horn is not a perfect 90 degree angle.

Pictured below is a ram that Colburn and Scott Outfitters Hunter Ron Arndorfer harvested in 2010.  This desert ram completed Ron's Grand Slam of North American Wild Sheep.  Ron's ram officially scored 170 3/8 Net Boone and Crockett.  This ram is going to be the feature ram for this field judging and scoring Desert sheep exercise.
These yellow lines are for example only and are obviously not exact.  The lines in reality are actually cylinders shapes that go completely around the horn.  I tried to draw them as close to where the circumference measurements should be taken.  It is important when you are glassing and examining these rams to try to mentally estimate where the each measurement may fall.  Watch out for big cracks or holes in the horn.  If the quarter measurement falls within a crack or hole in the horn that can dramatically affect the measurement for that quarter ultimately lowering the score of the ram.  The circumference of the base is measured at a right angle to the axis of the horn. DO NOT follow the irregular edge of the horn; the line of measurement must be entirely on horn material.

(My lines may not be exact but are strictly to be used as reference) This picture is designed to show where the length of horn is measured from.  The length of horn is measured from the lowest point in front on the outer curve to a point in line with the tip. DO NOT press tape into depressions. The low point of the outer curve of the horn is considered to be the low point of the frontal portion of the horn, situated above and slightly medial to the eye socket (not the outside edge). Use a straight edge, perpendicular to the horn axis, to end the measurement on broomed horns.

For exercise lets dive into the numbers of this ram. The longest horn is 36 inches so the mass measurements for D1-D4 for each horn shall be 0, 9, 18, 27 on both the right and left horn.  This ram is pretty symmetrical and there are not a lot of differences in mass between each horn.  The D1 or Bases are the same at 14 3/8, D2 has a difference of 2/8", D3 has a difference of 1/8", D4 has a no difference.  So there is only 3/8 inches of deductions on this ram.  This ram grosses 170 6/8" and Nets 170 3/8"

Here is a picture of the left horn, notice it is broomed off more so it is obviously a little shorter than the left.  Left Horn Measurements, Horn Length 34 1/8, D1 14 3/8, D2 13 6/8, D3 12 5/8, D4 9 4/8 for a total of 84 3/8.  Once again the yellow lines are designed for example only and are not exact.  It is important to always be thinking about these different quarter measurements fall within the horn.  It gets easier to estimate and calculate the measurements when you break the horn down.

This is always a hard angle to field judge from.  I prefer a level head.  It is important to try and get front on, side on and rear views in order to see the entire horn.

Here is a picture of the right horn.  Right Horn Measurements are Length 36, D1 14 3/8, D2 14, D3 12 4/8, D4 9 4/8 for a total of 86 3/8

Here is another picture of the ram's right horn
It is always important to get a good view and picture or video of the back of the horn.  Notice on the rams right horn there is a pretty good sized divot out of the back of the horn.  When trying to estimate the score it is important to determine if the quarter measurement will fall within that divot.  If it does it may lower the score of the ram.

Congrats to Colburn and Scott Outfitters hunter Ron Arndorfer for completing your grand slam with this fine Arizona Desert Bighorn Sheep.

For more videos and pics on Arizona Desert Bighorn Sheep see the links below
Arizona Desert Bighorn Sheep Hunting Videos
Arizona Desert Bighorn Sheep Hunts
Arizona Desert Bighorn Sheep Scouting Photos
Scoring and Field Judging Bighorn Sheep magazine article
Record Book Trophy Animals Harvested

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