Spending the Evening with Four Men in the Back of a Pickup Truck
Wood County, Texas’ Holly Lake Ranch has a lot of deer. So many have been seen that community leaders determined a spotlight deer survey needed to be performed to see exactly how many. So, guess whose little hand went up to volunteer to help with this endeavor? Right, mine. I bet you all are jealous that you were not the ones riding around in pick ‘em truck in the middle of the night. The following is a recount, to the best of my recollection, of this fun filled evening and exactly what we did.
Our community obtained a vehicle just for this special occasion. Now this truck isn’t one of the new, cute girly trucks. It is a big, old F110 with a bench seat that is held together with duck tape and baling wire. A board is secured, with vice type clamps, across the sides of the bed truck for seating for the spotters. Spotlights are wired into a battery in the cab. There is a lawn chair for the recorder. There is a driver, two spotters and a recorder. It was deemed that this journey should begin at 9:00 p.m.
Now, I don’t remember drawing straws on who gets to do what. Remember we have one driver, two spotlight people and one recorder. I guess community officials determined that I could neither operate a spotlight nor a pencil and paper. So, guess who got to drive the truck for the deer count . . . moi!!! Hoping everyone’s life insurance is fully paid, I acquiesced.
Now, since the bench seat was unmovable, I had to pull myself up by holding onto the steering wheel just to reach the gas and brake pedals. Thank goodness it was not a manual transmission. I could barely see over the steering wheel let alone the hood of the truck. I had to drive the truck at a speed of 5-7 miles per hour for 4 hours all the while holding myself up by grasping the steering wheel. No causalities occurred but one mailbox came close to being creamed.
Now on to the count. Three counts are taken during a period and then a Texas Parks and Wildlife Biologist will extrapolate the data. He will train a Wildlife Group here in our community in these computations so that we may do this study on a yearly basis. But for all you math whizzes out there, I am going to give you the formulas. Get your slide rules ready.
The first task is taking visibility readings every 1/10th mile. The following formula is used to convert 1/10-mile visibility estimates into acres of visibility:
Total yards of visibilities / number of 1/10mile stops +1 X Number of miles X 1,760 / 4,840 = Visible Acres. For example, a 7.7-mile line with 4,744 total yards of visibility the formula would be: 4,744 / 77 + 1 X 7.7 X 1,760 / 4,840 = 170.29 acres. Got that?
Then you divide the total number of deer into the total number of visible acres observed to determine the number of acres per deer on the route. For example: 1,260 acres (one spotlight survey route run 3 times with 420 acres of visibility) divided by 90 (total number of deer observed on that spotlight survey route run 3 times) = one deer per 14.00 acres. The estimated deer population for this area can then be estimated by dividing the total acres by the estimated acres per deer figure. For example, the deer population estimate for a 5,000 acres ranch with a deer density of one deer per 14.00 acres is 357 total deer.
Also included in this survey will be buck, doe, and fawn ratios. An estimate of the number of bucks, does, and fawns in the population can then be determined by multiplying the total number of deer by the percent of all deer identified that were bucks, does, and fawns. For example:
357 Deer X 0.20 (% identified as bucks) = 71 bucks,
357 Deer X 0.50 (% identified as does) = 179 does, and
357 Deer X 0.30 (% identified as fawns) = 107 fawns
TOTAL = 357 deer
In addition, deer identified as bucks, does, and fawns from the spotlight surveys can provide important information on the buck to doe and fawn to doe ratios. Herd composition is crucial to management of deer populations. The ratio of bucks to does provides information on survival of both sexes and is an indicator of hunting pressure on each sex. Fall fawn per doe ratios provide a good index of fawn survival.
Well, if that doesn’t curdle your brain, I don’t know what will. Whatever the final numbers are, it is good that the community is being proactive in keeping our area beautiful with herd of healthy, vibrant deer.