Deer Herd Management for Georgia Hunters
One good rule of thumb is that it is much easier to manage the deer population and reach your harvest objectives on larger land areas. For example, a club leasing 2,500 acres has a greater chance for successful management and achieving objectives than a club which leases only 500 acres. The reason, of course, is that deer do not recognize ownership boundaries and often have home ranges which span across two or more adjoining clubs or leases. Other clubs harvest strategy may be different from yours. For example, while your club may be managing for quality deer by restricting antlered buck harvest the adjoining club may be killing too many bucks but not enough does. Some of these bucks will likely be bucks you have passed! One obvious solution to this problem is for two or more adjoining clubs to share information and cooperate on their deer management objectives. The combined acreage of cooperating adjacent clubs can be much more productive and successfully managed.
Harvest strategies will differ depending on your objective and the harvest approach required (stabilize, increase, or decrease) to meet your objective. Also, the size and composition of harvest are linked to the physiographic regions of Georgia and the quality of the habitat within a region. The Piedmont, Ridge and Valley, and Upper Coastal Plain Physiographic Regions are the most productive deer regions in Georgia and contain the great majority of deer leases. The Mountains and Lower Coastal Plain Physiographic Regions are less productive for deer and contain fewer deer leases. To put deer harvests in perspective, a harvest of 5 deer per square mile (640 acres) is good in the Mountains and Lower Coastal Plain and 15 deer per square mile is good in the other regions. Harvests exceeding 25 deer per square mile have commonly occurred on small land areas in the Piedmont.
After you have collected the necessary data from your harvest and determined your management strategy for the herd (maximum population, maximum harvest, quality management or trophy management), you can begin to work toward that objective. Use your data to determine the current herd status. You will need to know the total antlered buck harvest, total number of yearling ( l.5 year old) bucks and the average beam length of yearling bucks.
1. Determine the average beam length for yearling bucks by adding the beam lengths of all yearling bucks and divide this total by the number of yearling bucks to get the average.
2. Determine the % yearling bucks in the harvest by dividing the number of yearling bucks by the total number of antlered bucks.
3. Determine the total buck harvest per square mile (640 acres) by multiplying your harvest times 640 then dividing by the acreage in your club.
Compare these values to columns A,B, and C in the harvest strategies table (Adobe Acrobat Reader required) to determine the present status of your deer herd (column D). Column E shows the population level relative to carrying capacity of the habitat. The next step is to fill in the number of bucks you harvested last season into column F in the same row with your current herd status. Finally, determine your doe harvest goal for next season by multiplying your total buck harvest by the appropriate factor in column G to reach your deer management strategy (column I). Following this recommendation for doe harvest is the key to the success of your program. It is more important than passing up bucks. Column J will show you the expected trend in the deer population if you meet your doe harvest goal. It may take two or more years to see measurable changes in the deer herd. A commitment to stick with a management program for several years is necessary to see measurable results.
Let's use the 700 acre Big Buck Club for an example (provided in the harvest strategies table) . A summary of their kill sheet shows 12 antlered bucks and 7 does killed. Yearling buck beam lengths averaged 7.8 inches and there were 58% yearlings (7/12) in the kill. Buck harvest per square mile was 11 (12*640/700). The club currently fits in Maximum Harvest but their goal is Quality Buck. To get there multiply 12*1.2 (Doe Harvest factor) to yield a Doe Harvest Goal of l4 and decrease the population.
Consequently, the Big Buck Club will need to double the doe harvest to 14 does and reduce the buck harvest to about 6 bucks. Additionally, they need to reduce the percent of yearling bucks in the harvest. As you can see from this example, the key to the population size, total number of bucks and antler quality is both the number of bucks and especially the number of does in the harvest. The necessary number of does to harvest is presented as a percentage of last year's antlered buck harvest.
What about button bucks? Despite your club's best possible intentions to pass up button bucks, there will undoubtedly be several taken. Don't worry too much about this. A modest harvest of button bucks will not affect the success of your program. However, for purposes of simplifying our calculations, don't include button bucks in any of the harvest totals or formulas used in the table.
Given a choice of objectives, most hunting groups will probably choose the MAXIMUM HARVEST or QUALITY DEER harvest options. These are actually very similar strategies, except for the intensity of adult buck harvest. However, if there is a lack of information about their deer herds, many clubs almost inevitably seem to manage conservatively for MAXIMUM POPULATION by harvesting too many antlered bucks and too few does every year. Over the span of a couple of years, this causes antler declines and habitat deterioration due to overpopulation caused by poor food supplies and decreased carrying capacity. It also creates a skewed sex ratio favoring does.
When accurate records are lacking, a good rule of thumb to stabilize a heavily hunted population (i.e. high buck harvest) is to harvest does at the rate of 0.6 that of the antlered bucks. The reasons for this doe factor are: 1) does are usually born into the population in slightly lower numbers than bucks; and 2) does often die from causes other than legal hunting at a higher rate than bucks. This percentage will stabilize the population in most cases where there are no buck harvest restrictions. If any restrictions are placed on the antlered buck harvest (such as a season bag limit of one per member, or antler restriction of 4 points on one side, or any reduced hunting pressure on bucks in an effort to maintain an older age structure) then this stabilization factor often exceeds 1.0 (does per antlered buck). These percentages are reflected in the harvest strategies table, options 2 or 3. Many clubs statewide are currently harvesting less than 50% does per antlered buck each year even though the statewide average has been running near 50% for several years. Low doe harvest rates on some clubs combined with excessively high harvest of bucks each year, causes a steadily increasing population in which body and antler conditions decline, the population sex ratio skews greatly toward does, and fawn production per doe declines.
If your club has decided to select QUALITY DEER MANAGEMENT (QDM) or TROPHY BUCK MANAGEMENT strategies, then you must limit the percent of yearlings in the harvest to less than 50%. Success in these strategies is determined in part by the number of bucks harvested during the season. Typically, you can not harvest more than 5 bucks per square mile in QDM or TROPHY BUCK MANAGEMENT. This will often require a reduction from your current buck harvest. Although this reduction will not be easy, there are several ways to accomplish it. One is the season limit rule where all harvest of antlered bucks on the club is stopped as soon as the season limit (6 in our example) is reached no matter when this occurs during the season. Another approach is to reduce the antlered bag limit per member from 2 to 1. Of course, one possible method of reducing buck harvest is selection based on antler size. A selective buck harvest system can be installed to successfully implement the QUALITY DEER or TROPHY BUCK options. There are many variations of this basic selective harvest theme that can be tailored to the club and the habitat. Two methods which are already being implemented in several Georgia counties are to harvest 1). bucks with 4 points on one side or better; or 2) bucks with a 15-inch or greater outside spread. All smaller bucks are passed up. (Note: a 15-inch spread is the approximate width between the tips of bucks' ears when they are extended outward in alert position). This restriction criteria is only appropriate for the best habitat and consistent "big deer" areas. We recommend against a 16-inch spread restriction because in many parts of Georgia even 4.5 year old or older bucks will not exceed this spread.
A selective harvest system must be carefully tailored to the condition of the deer herd. Shooting all spike bucks in parts of the Mountains and Coastal Plain, for example, would be counter- productive since virtually all of the 1.5 year-old bucks are spikes in these areas. On the other extreme, in portions of the Piedmont and Upper Coastal Plain, there are many herds which have less than 50% of the yearling bucks with spikes. Some clubs take some spikes under these conditions in an attempt to influence the genetic quality of the deer herd. Whether it really does any good or not probably varies on every piece of property and is still a subject for debate. Given older age, spikes will usually grow to reasonable quality bucks. It is unlikely that selectively harvesting spikes will improve the quality of the herd. Wildlife biologists can provide valuable information and advice on selective harvests tailored to your local area and the condition of your deer herd.
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