QDMA Articles
By: Kip Adams
Deer managers are often asked about “cull” bucks. Specifically, which bucks should be culled to improve herd quality? Cull bucks are defined as those deemed to be of inferior (usually antler) quality. The answer to this question depends on several factors including the intensity level and goals of your management program, amount of control you have over the deer herd’s mortality sources, relationship between the deer herd and the habitat’s carrying capacity, and the herd’s adult sex ratio and age structure. The variety of factors influencing this decision causes a variety of answers depending upon who you ask.
Let’s begin by looking at what affects antler growth. We all know that age, nutrition, and genetics play key roles. However, with the minimal amount of control that most managers have on breeding parameters or paternity selection, genetics is often overrated. Most deer managers have little or no control over genetics, but they can vastly improve age and nutrition. Therefore, managers should do everything possible to increase the number of bucks in each age class and improve the available nutrition for the deer herd.
Some managers fool themselves into thinking they can accurately identify bucks that should be removed. Some biologists have enough experience and enough knowledge about individual bucks (over multiple years) to accurately identify top cull buck candidates, but most of us don’t and here’s why.
For practical reasons, we’ll limit this discussion to yearling bucks. Antlers on bucks 2.5 years and older are affected by the following factors plus others and are a topic for another article. Antler size and conformation can be affected by several environmental factors and you can predict very little about a buck’s future potential by its first set of antlers. Yearlings’ antlers range from short spikes to 10 or more points and are influenced by: 1) Birth month – fawns born earlier (e.g., May) have more time to grow before the onset of winter, and larger fawns generally have higher winter survival rates and a larger first set of antlers; 2) Mother’s age – adult females typically breed and fawn earlier, thus providing a longer first growing season for fawns; 3) Number of siblings – multiple fawns place higher energy demands on the mother and increase competition for resources between individuals; 4) Weather conditions – April showers provide abundant forage needed by females to provide highly nutritious milk to fawns. Droughts and floods can negatively impact fawn development; 5) Mother’s physical condition – the previous fall’s mast crop and previous winter’s severity can have dramatic impacts on adults’ and fawns’ physical conditions; 6) Herd density – if herd density is above carrying capacity bucks likely won’t get adequate nutrition to fully express their antler potential; 7) Mother’s social rank – mature, dominant females select and defend the best fawning habitats. Fawns born to such females theoretically begin life in higher quality habitats than those born to subdominant females.
As you can see, many variables define what a yearling buck wears on his head. For example: a buck with below average antler potential at maturity is born to a dominant doe surrounded by lush vegetation in May, following a bumper acorn crop and an easy winter. Because of the favorable conditions, this buck could be expected to have an above average first set of antlers. Conversely, a buck with world record potential is born to a subdominant doe from an overpopulated herd in the middle of a drought in July, following a mast crop failure and/or a hard winter. This buck will likely have a small (e.g., spike) first set of antlers. You tell me, should that spike be removed from the herd? Absolutely NOT! My suggestion – let him and all yearling bucks walk. Remember, a primary goal of Quality Deer Management is to increase the number of bucks in the 2.5+ year-old age classes, and removing any yearling buck is counterproductive to that fundamental goal.
Kip’s Korner is written by Kip Adams, a Certified Wildlife Biologist and Northern Director of Education and Outreach for the Quality Deer Management Association (QDMA). The QDMA is an international nonprofit wildlife conservation organization dedicated to ethical hunting, sound deer management and preservation of the deer-hunting heritage. The QDMA can be reached at 1-800-209-DEER or www.QDMA.com.
