How to conduct a deer census
In order to effectively manage your wildlife, an annual census of the whitetail deer population is necessary. Knowing the numbers as well as composition of the deer herd on your property is vital to an effective management plan.
Deer population is estimated using a sampling technique. A 2 mile line is the standard used for taking a walking census. The line is laid out on east to west and always walked from west to east (sun at your back).
To calculate the acreage observed, measure visibility every 100 yards along the course. In other words, measure how far you can see to calculate the average width of the census line. We'll use this information later to calculate the acreage that was surveyed to obtain our deer density per acre.
Ideally, you will do a census line for every 1000 acres on your property. The more census lines, the more accurate the count. The line(s) should be walked at least twice and the results averaged. Again, the more samples taken, the more accurate the count.
Walk the line (west to east) in late September or October, starting 30 minutes before sunset. All deer should be recorded, distinguishing between bucks and does. The line should be walked when the weather is decent - southerly wind less than 15 mph, less than 50% cloud cover, RH less than 70%.
Example of the calculations:
A census line is two miles long and average of 150 yards wide.
2 miles times 1760 yards = 3520 yards length
3520 yards (length) times 150 yards (width) = 528,000 square yards
528,000 divided by 4840 (yards per acre) = 109 acres
If 15 deer were seen, then 109 acres divided by 15 deer = 7.2 acres per deer.
If your place is 1000 acres, then 1000 divided by 7.2 = 138 deer total.
If 6 bucks were seen, then 109 acres divided by 6 = 18.16 acres per buck.
If your place is 1000 acres, then 1000 divided by 18.16 = 55 bucks total.
All things being ideal, this census should be accurate within + or - 10%. Again, the more census lines and the more samples taken and averaged gives a more accurate count.
A very similar method, considered by many to be more accurate is the spotlight technique. Counting deer at night using a vehicle. One person drives and two in the bed of the truck spot and count.
The spotlight census should be conducted 45 minutes to an hour after sunset. Drive about 10 mph. Texas Parks & Wildlife uses a census line about 15 miles long. The length will vary depending on the size of your place. Measure the width about every one tenth mile and use the same math as above to calculate deer density.
Again, conduct during good weather. If you need more information, please contact us!
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