ANNUAL REPORT ON DEER MANAGEMENT
GLASSCOCK ISLAND AUGUST 2006
By: Harry A. Jacobson, PH.D.

The population estimate should be considered as conservative. Fall camera surveys usually can be expected to underestimate doe numbers and are of little value for estimating fawn numbers. However, most bucks can be expected to be photographed. Based on the high adult doe lactation rates seen in the harvest statistics (80%), I also estimate very good fawn recruitment in 2005 and approximated this at about 1.2 fawns per doe or 278 fawns. From these numbers and after considering the 2005 harvest, natural mortality, and crippling loss, I would estimate around 200 bucks of all ages will be present for the 2006 hunting season along with about this same number of does.

All condition indicators from harvest data indicate the Glasscock Island deer are in outstanding health. Body weights of both bucks and does are at the highest they have ever been with mature bucks topping the scales with average weights of 217 lbs. Doe age structure is very young with almost 75% of the does harvested younger than three years old. I attribute this to substantial doe harvest over the past ten years bringing about a reduced deer population in optimum balance with its environment along with the greatly improved agricultural food plot effort during the last three years. Add to this a much improved buck age structure with the establishment of the 22 inch beam length rule and it is hard to find much room for improvement.

With the above said, there still are a couple of areas that could contribute to the Glasscock deer management program reaching even a higher level, as good or better than any other area in the state. The first of these is continuing evolution of the hunters on Glasscock to recognize the ages of adult bucks and to further restrain from the harvest of two year and three year old bucks in favor of harvesting only mature bucks. Currently less than 30% of the bucks harvested have reached the age classes of four years or older. Letting bucks reach these age classes can be expected to add at least 20 or more inches of antler over that of the same bucks at three years of age. Letting these same bucks reach ages of five or more years can often add as many as 30 or more inches of antler over that of the same bucks as three years of age.

Another area which could contribute to a better management effort is to further improve record keeping. Insuring jaws are collected and labeled from all deer harvested is extremely important to the management effort. Filling out observation cards on bucks does and fawns seen during the hunting trip can provide a much more precise means of estimating population age and sex structures. When such observations can be matched to our camera photo census data, it will provide a much improved means of determining how many deer should be harvested by sex to meet management objectives.

The final area of concern I have after examination of our photo census information is that we are harvesting at a very high rate the best bucks in the genetic pool. In particular very few bucks are present which have ten point main frame antlers. The significance of this is that bucks with ten point main frames will generally outscore similar aged bucks by ten to twenty inches because of the added antler mass measures and typical tine additions. The magnitude of this problem can be recognized by the fact that of the 193 bucks I estimated to be individuals photographed in our 2005 census, only seven had ten or more main frame points. Four ten point main frame bucks were harvested and one additional main frame ten point was found dead, having locked antlers with another buck. No ten point main frame bucks were seen in the 2004 season harvest photos.

Because of the above, I would like to recommend the protection of ten point main frame bucks from harvest for a two year period, followed by conservative harvest after that. I have seen substantial results in dramatically improved antler characteristics on Mississippi Delta clubs that have implemented this harvest strategy. In one case in the Arkansas Mississippi Delta I watched ten points go from less than three percent of the total bucks present (approximately the same as on Glasscock) to over twenty percent in three years time. It is too soon to tell the ultimate effect of this on genetic qualities, but I think it safe to assume these bucks will continue to show up in much higher prevalence in the future on these areas. With the current quality of other antler measures of Glasscock bucks, I think it is not difficult to imagine that with a substantial increase in ten point main frame bucks in the breeding pool, the harvest of 180 inch class bucks can definitely be achieved within the next six to ten years.

As for other harvest restrictions in the coming season, I would continue to recommend the same buck rues as last year along with the ten point “main frame” restriction. This still allows the harvest of bucks with ten or more points as long as they don’t originate on the top of the main beam and would be scored as B&C typical antler points. This only results in a very minor reduction of total bucks for harvest in the short term but can result in substantial improvement in buck quality in the longer term. As for doe harvest, unless the current fall camera survey indicates high numbers, or I find upon inspection of browse and habitat conditions during the fall indicates a population problem, I am recommending a conservative doe harvest of 90-120 does. My reasons for this are improved habitat conditions from agricultural planting, a population estimate of approximately 200 does present, and the young age structure of does in the 2005 harvest. This number is tentative and could be changed dependant on further population survey and habitat evaluation.

I hope you find the current condition of the Glasscock Island deer herd as exciting as I do. Time will tell, but it should be a very good year!

Good Hunting,

Harry A. Jacobson, Ph.D.
Certified Wildlife Biologist