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Department of Natural Resource Ecology and Management

Deer Census

NREM Extension offers a variety of educational programs for adults. Current programs include:

The Stewardship Forest Certification

Master Naturalist Program

Field Tours and Demonstrations

Conducting Deer Census

 

Conducting Deer Census

Determining the number of deer you have utilizing the resources on your property is a valuable piece of information. This will allow you to know if there are more deer in the area than the resources can support as well as how your harvest management is changing density, sex ratio, doe/fawn ratio, etc. The most accurate method to determine densities is the use of motion activated trail cameras. This survey method involves baiting the deer to come to the camera sites. Thus, it should be conducted during a time when food sources are least abundant such as December or January. Studies have shown that one camera per 100 acres is optimal to achieve the most accurate results. Once you have identified one spot for each 100 acres, you must prebait the site for 10-14 days. Prebaiting with corn or milo is effective. Only by saturating the landscape with baited camera stations will you be able to determine sex ratios as bucks tend to dominate sites when only a few cameras are present and you will not be able to calculate sex ratios. Thus, this method is not very effective for areas less than about 1,000 acres. If you own or manage less than this acreage, consider forming a hunt cooperative with your neighbors to conduct surveys and other management actions. This will not only enable better deer management, but you can also spread out the expense of the cameras.

Upon completion of prebaiting, you should install the camera and set it to take a picture every 4 to 5 minutes when activated. The camera should be placed about 10-15 feet from the bait pile and pointed north to avoid sun glare in the photos. Any vegetation that the wind might move will need to be mowed down to avoid unnecessary photos to sort through and to conserve battery life. Camera stations should be placed in locations that are easily accessed in order to save time when checking them during the survey period. The camera stations will need to be checked about every 3 to 4 days to replenish bait and make sure the camera is working correctly. The cameras need to be functioning for 10 days to two weeks in order to capture the majority of the deer in the area. After this period has ended you count the number of deer captured in the photographs. The calculations for interpreting the number of deer are based on the number of identifiable bucks observed in the survey. This means that you will need to save a picture of each different buck you find to calculate the total number of bucks identified in your survey. Thus, surveys should be completed before antler drop which can begin in January in Oklahoma. When looking through the pictures, you will need to record whether it was a buck, doe or fawn. If a picture contains a buck, doe and a fawn then you must record one count for each category. When you are finished examining the pictures you will have the total number of times a buck, doe, or fawn was captured in a photograph. The first step in the calculations deals with the bucks. Take the total number of times a buck was captured and divide that by the total number of identifiable bucks (determined by the unique antler configuration of that animal). This will give you an average number of times each buck was photographed. The next step is to take the total number of doe captures divided by the average pictures per buck. This will provide you with the number of does present during your survey. Note: The method is built on the assumption that bucks and does have equal chance of getting captured on camera (Thus, the importance of having many cameras in operation so that does are able to access the bait stations as well.) Take the number of captures of bucks divided by the number of captures of does to get the sex ratio. A 1:1 ratio is ideal. Take the number of captures of fawns divided by the number of captures of does to give you a fawn to doe ratio. This ratio multiplied by the total number of does present will tell you how many fawns there are. To calculate the density of deer on your property, combine the totals of bucks, does, and fawns and divide the number of acres on your property by this total number of deer captured. This will give you the density of deer on the property.


setting up trail cameraCameras should be placed 10-15 feet from the bait and aimed 2.5-3 feet above the bait to minimize photos of animals other than deer such as raccoons and crows.

The following are examples of the analysis of camera surveys:


Example 1

# of identifiable bucks = 38

Sex Ratio = 2,985 doe captures/1,950 buck captures = 1.53 does/buck

Estimated doe population = 38 bucks x 1.53 does/buck= 58 does

Estimated fawn population = 3,532 fawn captures/2,985 doe captures = 1.18 fawns/doe
58 does x 1.18 fawns/doe = 69 fawns

Total estimated population = 38 bucks + 58 does + 69 fawns = 165 deer

Density = 2,000 acres/ 165 deer = 12.1 acres/deer

Example 2

# of identifiable bucks = 30

Sex Ratio= 1,667 doe captures/ 1,118 buck captures = 1.49 does/buck 

Estimated doe population = 30 bucks x 1.49 does/buck = 45 does

Estimated fawn population = 1.321 fawn captures / 1,667 doe captures = 0.8 fawns/doe
45 does x 0.8 fawns/doe = 36 fawns

Total estimated population = 30 bucks + 45 does + 36 fawns = 111 deer

Density = 1000 acres/ 111 deer = 9 acres/deer

 

 

trail-camera-pic.pngAlways remember to point cameras north so sun lights the animal instead of glaring on the camera lens.