Estimating Deer Density
Updated: Mar 10, 2022
Every hunter wants to attract and maintain as many deer as possible, but sometimes it can be hard to get an accurate count of the true number of deer that utilize your property. Getting a 100% precise count of deer that use or even stay on your property, depending on the size area, can be nearly impossible to figure. Data from parcels under 100 acres can be inaccurate, so teaming up with neighboring properties and increasing the area you are collecting data over can increase the accuracy of your study. Using a few simple avenues that have been proven to estimate the density of the deer in a certain area, can be the best way to know what management strategies to implement to maintain or attract more deer on your property.
Pellet Count Surveys
A great way to kill two birds with one stone once the snow melts, is to get a group of people together to take a walk through your property while looking for sheds and counting piles of deer poop along the way. How fun does counting deer poop sound?! This method gets some boots on the ground and simultaneously gathers information about your property. Conducting deer pellet counts are the most effective in early spring right after the snow has melted. An organized hike with a few of your buddies can get you an accurate estimate of the number of deer that utilize your property in the fall and winter months.
Before heading into the woods, planning out straight lined, parallel transects across the property should be set up on a map and cover as much of the property as possible. The distance between transects are about 1500 feet apart and typically run from boundary line to boundary line. After lining up your group of people and everyone beginning their walk, each person should stop every 100 feet and count the number of pellet groups of deer droppings within a 4 foot radius in every direction. To be considered a pellet group, there must be a minimum of 25 pellets that are laying on top of the leaf litter. After recording your data for that stop, use a compass to continue in the same direction along your transect. Continue stopping every 100 feet and collecting data until you reach the end of your transect. You can repeat the process of lining everyone up and setting them out on transects until you run out of your property to cover or the group’s energy level. The more area you can cover and the more data you can collect, the more accurate the estimates can be. Using this specialized formula Calculate Deer Density = _______# Pellet Groups Counted_________________________________ Pellet Groups/Day x Days Since Leaf Off x Square Miles of Plot Area , you can analyze the data you collected to get one of the most accurate estimates of deer density within your property.
Camera Trap Surveys
A “camera trap”, or trail camera, can be one of the most simple, efficient and beneficial tools a biologist, land manager or hunter can use to “keep tabs” on specific individuals or the general number of deer in a particular area. Instead of just using a trail camera to get pretty pictures, using the situational data, like date, time or temperature, that trail cameras log each time a picture is taken can be a vital tool to determine the movement of wildlife through a property. In most states, across the U.S. trail cameras can be used year-round. The amount of intel “camera traps” can provide are priceless, and can be the difference between you and your target buck on the same or opposite schedules this season.
An ideal setup for a thorough camera trap study is having a basic ratio of one trail camera per every 100 acres of area you are looking to cover. Similar to the spotlight surveys, having cameras too close to one another can lead to including individual deer more than once in a count. The best way to set up a camera trap is to attach a trail camera on an existing structure about 4.5 feet off of the ground, and typically facing a north direction to avoid catching the movement of the sun throughout the day. Placing 40 pounds of Buck Yeah! approximately 10 feet in front of each camera, and replenishing the site every two weeks will provide efficient attraction. Typical camera trap studies are conducted over an extended period of time, from a few months to year-round, while gathering and saving every picture to be able to most accurately determine when individuals visited that location each day. Using this equation,(# bucks + # does + # fawns)/ total number of parcel acres, can be used to analyze all of the data camera trap surveys on your property have collected.
One of my favorite pastimes before archery season is “spotting” at least a few nights a week. Also called “spotlight surveys'', biologists and land managers use this technique of shining a light across an open space to get a census of the number and variety of wildlife that use a particular area. The best time to spot fields or open woods is in the late summer or early fall when temperatures are still warm enough that deer are in deep, cool areas during the day, and when temperatures chill down at night the deer venture out into more open areas to feed. Another reason spotlight surveys are most effective this time of year is because antlers are developed enough that it is easier to distinguish the sex of the animals at a distance.
Determining your route of travel is most important because you want to be sure that you are limiting the risk of including the same individuals more than once in your count. The best way to limit skewing your data, is to establish a route in a particular area that you only travel or get in close proximity to once a night. To get the most accurate results, this study should be completed during the same time frame over the course of multiple nights. Completing a spotlight survey requires a minimum of 2 people. One person will be solely focused on driving the vehicle and when they stop every 1/10th of a mile, the other one or more individuals will spot the areas to the left and right of the vehicle and record the number of bucks, does and if there were any deer they were unable to identify sex on. The driver will stop the vehicle every 1/10th of a mile until the route is complete. Once the route is completed multiple nights at a consistent time frame, the numbers of individuals counted on each night's survey of the route are added together and divided by the number of times the route was surveyed. Entering the data you have collected on your several trips out, you can use equations like using the formula Area (A) = L x W, then distance traveled (L) x average sighting distance (W) would be the square yards (A). And since there are 4,840 square yards in an acre, if we divide # acres by 4,840 you will get the surveyed acres (SA). Then take the (SA) / (# bucks # does+ # fawns) = Estimated deer population, to estimate the deer density on your property.
Take it to the Field
Using the same techniques you learned above, land managers can estimate deer density and other factors, like sex ratios, to figure out the best management practice that will have the best benefit to the herd. Implementing data collection on herd demographics and density, as well as how the deer use your property, can save you time and money when deciding where to focus the management efforts on your property.