Buck to Doe Ratio – How to Calculate
Trail cameras can provide the intelligence needed to move in close enough to harvest a mature buck. However, they will also supply you with the information necessary to make sound management decisions. If managing your property is your objective, trail cameras will help you to learn the density, buck to doe ratio and get a good guess on the age structure of the herd. This, in turn, will give you what you need to know to make numerous management decisions, especially those “trigger finger” management decisions – how many deer need to be harvested and which ones.
The simple formula below is widely used for determining a ballpark buck to doe ratio in a given area – I think I first stole it from the QDMA, but I’ve seen it elsewhere. You must use multiple camera locations and run your cameras for a period of one to two weeks in each spot. If you only have one camera, run it for a week or two and move it at least 200 yards to a new location. Keep your cameras moving! The more data you collect the more accurate your results will be.
- Total pictures of bucks = X
- Total pictures of unique bucks = Y
- Total pictures of adult does = Z (not fawns)
- Doe multiplier = B
Y÷ X = A
A x Z = Number of Does
Y ÷ B = Buck to Doe Ratio
EXAMPLE #1
- 56 pictures of bucks with 12 being unique. | 12 ÷ 56 = .2142
- 200 pictures of adult does without counting fawns | .2142 x 200 = 42
- So 12 bucks for every 42 does. Your exact ratio would be 12:42. So your buck to doe ratio would be roughly 1 to 4.
EXAMPLE #2
- 1,178 pictures of bucks with 17 being unique. | 17 ÷ 1,178 = .0144
- 2,368 pictures of adult does. | .0144 x 2,368 = 34
- So 17 bucks for every 34 does. Your ratio would be 17:34. So you could claim a buck to doe ratio of a little better than 1 to 2.
Mississippi State University researchers developed and refined an infrared camera survey technique that can provide an accurate assessment of your local deer population with a surprisingly small investment in time and equipment.
How many cameras per acre are needed to calculate buck to do ratio?
If you can come up with one camera per 100 acres, that is sufficient. For optimum results you should conduct two surveys – one just before hunting season and another just after. Established feeding stations will be your best tactic. Pre-bait each site for at least five days and try to include enough food to last throughout the survey period. You don’t want to disturb the site during the survey if you can help it.
Divide your property into blocks approximately 100 acres in size. Place one camera in each block. Don’t worry about including areas not ordinarily utilized by whitetails. As an example, there’s no need to run a camera in the middle of an open field. Short survey periods of 5 to 10 days are adequate, but you’ll attain greater accuracy running each site for 10 days to two weeks. If you only have one camera, run it for about 10 days in one location, while in the mean time you prime (pre-bait) the next location in the subsequent 100 acre block.
Make sure the cameras are set up to stamp the correct date and time. And just as you would with any camera set-up, point the camera to avoid backlighting and clear all vegetation from the detection zone to prevent false events.
How to count for accurate ratio:
After the survey is complete, compile all of your photographs and count the number of bucks, does and fawns. For bucks, count the total number of bucks in all photos, including all repeats. You will also need to know the actual number of unique bucks. So I don’t have to go through the images an extra time to count individuals, I usually keep a running tally as I count total number of bucks.
The easiest way to distinguish an individual buck is by using antler characteristics such as number of points, abnormal points, tine length, spread and other distinguishable antler distinctiveness. However, body characteristics will also help once you get used to looking at countless whitetails. The result is your buck population.
For does and fawns, count the total number of does and exclude any deer from the survey that you cannot identify. This is valuable information. In addition to the buck-to-doe ratio, once you look at thousands of photos and become skilled at identifying certain characteristics, you can even age the bucks, and then rank them by age class to determine age structure. In fact, you can often get good enough at “reading whitetails” so you can tell the difference between individual does.
Repeating this survey over numerous consecutive seasons allows you to study trends, which can be more valuable than an actual population estimate for any given year.
Speaking of cameras; now land managers are beginning to use UAVs or “drones” with cameras on them to get a birds-eye view of their property. Ethically, I would never think of using one for hunting, but I have to admit I can see some management applications. I believe they should be illegal for hunting, but they could be useful for monitoring crops, showing others stand locations, property boundaries or other property features without physically disturbing the area, or could be very helpful in locating a downed animal. We’re going to have to deal with crafting new laws so that these tools cannot be misused, but are not illegal to use for common sense operations.
Develop a system for filing your photos. To really effectively manage a property you must be good at keeping records. Now days, one property manager on a 500-acre parcel can go through 200,000 images or more in one season. Whether you categorize your files by date, place where the camera was located, the specific buck you’re after or some other system, it’s important to find a way to organize your images so you can find them when you need to recap.
Trail camera photos are one of the primary ways to learn what’s happening on your property. They help you to gather information on mature bucks, document trends over the years and there is no better way to determine density, buck-to-doe ratio or age structure of your herd.
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