The Experimental Antler Point Restriction

By Lonnie Hansen | September 2, 2008
From Missouri Conservationist: Sep 2008

The 475,000 Missourians who hunt white-tailed deer and the many Missourians who enjoy the thrill of seeing the graceful animals in the wild believe that as far as Missouri’s deer herd goes, “the more the better.”

On the other hand, landowners who see deer feeding in their fields and motorists who worry about deer on the roadsides might say Missouri has too many deer.

Balancing the interests of these groups with opposing viewpoints is a challenge the Conservation Department continually addresses.

Our most effective tool for managing deer numbers is hunting. Surveys tell us, however, that this tool might not be as reliable in the future as it has been in the past because the average age of deer hunters in Missouri is slowly increasing, which suggests declines in the number of deer hunters might occur.

The Conservation Department has been testing various regulations that might enable us to manage deer populations with fewer hunters. Studies clearly tell us that the best way to control deer numbers is to balance the ratio of bucks to does in the population. If two out of three deer are does, for example, you’re more likely to have population bulges than if the numbers of does and bucks were closer to equal. The proportion of does in the total population is one key to manageable deer numbers.

Since 2004 we have been testing an Antler Point Restriction in 29 Missouri counties to see if it would reduce the percentage of does in the deer population. The APR requires a buck to have at least 4 points on one side to be legal. The restriction applied to the archery season and all portions of the firearms season except the youth portion. The expectation was that restricting the bucks that could be taken would promote a larger doe harvest. An additional benefit of this restriction would be that more bucks survive longer and grow antlers large enough to be considered trophies by hunters.

We selected two groups of counties for the APR—a northern and a central group. The northern group of counties was mostly agricultural land with generally high deer densities. The central group of APR counties was Ozark fringe, where deer densities are moderate. We separated the northern and central APR counties when evaluating the effects of the APR.

Originally, we planned to evaluate the biological effects of the APR and hunter and landowner attitudes toward deer management and the APR for three to five years. We decided after the 2007 season (four years) that we had adequate information to determine how well the APR worked and to make decisions on how it should be applied in the future.

We determined sex and age of harvested deer from 2003, before the APR was implemented, through 2007, the last year of the study.

To better gauge the effect of the APR we compared information collected in APR counties with information from adjacent “control” counties without the APR.

Data collected for analysis included checked deer (classified as button buck, doe or antlered buck) and deer sampled at biological data collection sites (check stations in 2003; meat processors in 2004–2007). We collected two incisor teeth from deer at least 2.5 years old to obtain more precise age information. For antlered deer we recorded the number of points at least 1 inch long on each beam, the length of the right beam, and the circumference of the right beam 1 inch above the base.

To determine the impact of the APR on harvest we assumed that any annual changes we saw in deer harvest would be the same in the APR counties as it was in the control counties. For example, if we saw a 10 percent annual increase in the doe harvest in the control counties, we expected the same increase in the APR counties. We attributed any differences between the actual doe harvest in the APR counties and the expected harvest to the APR.

Our assessment of public attitudes included random surveys of hunters and production landowners, written and Web-based comments, and comments offered at 16 public meetings held during January and February 2008. About 24,000 Missourians provided opinions about the APR and other deer management issues.

Biologic al Effects

The Antler Point Restriction had little effect on the doe harvest in the northern counties, but in the central APR counties the doe harvest increased an average of 13 percent over the four-year study period.

The APR reduced the harvest of antlered deer in both the northern and central APR counties. The reduction ranged from 35 percent in 2004 to 14 percent in 2007 in the northern APR counties, and from 37 percent to 19 percent in the central APR counties. The reduction consisted mostly of yearling bucks, because the majority of bucks in this age class did not qualify as legal deer under the APR.

Harvest of adult bucks was slightly lower in the APR counties in 2004, but increased in all of the following years. By 2007, the number of adult bucks harvested in the northern APR counties increased by 55 percent, and in the central pilot counties by 62 percent. Because the number of adult bucks taken in the northern and central control counties also increased, the adjusted change was to 16 percent and 32 percent in the northern and central APR counties, respectively.

The increase in the number of adult bucks taken in the control counties might have been a result of an increasing number of hunters deciding not to shoot young bucks even though doing so was legal. We suspect the APR regulation might have prompted and accelerated this voluntarily restrictive harvest, producing higher adult buck harvests.

Total harvest declines in the northern APR counties ranged from 14 percent in 2004 to 8 percent in 2007, and from 3 percent in 2004 to no change in the central APR counties. Continuation of the APR likely will result in 5–10 percent fewer deer harvested annually in the northern APR counties and will have no effect in the central APR counties. That’s because the increased harvest of does and adult bucks in the northern counties did not offset the decrease in the yearling buck harvest, as it did in the southern counties.

Social Effects

The Antler Point Restriction was popular in both the northern and central APR counties. The restriction became increasingly favored in the APR counties during the course of the study, but there was no change in acceptance of it in the control counties.

Although popular overall, acceptance of the APR varied throughout the state. The percentage of surveyed deer hunters in favor of the APR was greatest in northern Missouri. We found much less support for the restriction in the south, particularly the southeast part of the state.

Study Conclusions

Although we did not achieve all of our biological objectives, the APR increased the harvest of adult bucks, increased doe harvest in central APR counties and was generally popular and well supported where implemented. In other words, we consider the APR a helpful management tool.

For 2008 the Antler Point Restriction will be expanded to include 65 counties, mostly in northern and central Missouri. Some counties in southwestern Missouri were excluded because of concerns about deer population declines that have occurred there over the last few years, even though there was public support for the APR. We also excluded urban counties in the St. Louis and Kansas City areas because of the need to harvest as many deer as possible—bucks and does—to reduce conflicts with human activities.

Deer populations in southeastern Missouri are low. We do not need to increase doe harvests there, and a restriction that prohibits hunters from taking a yearling buck would significantly reduce harvest opportunities for some hunters.

We will annually review the results of the APR and may add or remove counties depending on biological issues and public interest. Missouri deer hunters can expect that we will continue to strive to manage deer populations in a way that ensures a healthy deer herd in line with the desires of hunters, landowners and the general public.

Also In This Issue

Feral hogs, now established in more than 20 counties, are a growing concern for Missourians.
A photographic essay on the beautiful and diverse landscapes of Missouri.

This Issue's Staff

Editor In Chief - Ara Clark
Managing Editor - Nichole LeClair
Art Director - Cliff White
Writer/Editor - Tom Cwynar
Staff Writer - Bonnie Chasteen
Staff Writer - Jim Low
Photographer - Noppadol Paothong
Photographer - David Stonner
Designer - Stephanie Ruby
Artist - Dave Besenger
Artist - Mark Raithel
Circulation - Laura Scheuler