BACKGROUND
F
ive years ago, I wrote an article for Whitetail News titled "The Cat’s out of the Bag." The article dealt with the forage preference study I’ve conducted at my whitetail deer behavioral research facility on our farm in western New York. At the time, the research centered on whitetails’ preferences for three forages: clover, chicory and brassica. Since then, we’ve expanded the study to include several other forages. What we’ve discovered is very interesting.
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In addition to writing and photographing whitetails, I’ve spent the past 30 years researching their behavior — everything from rutting to food preferences. In 1995, I expanded this research by constructing a 35-acre high-fenced research enclosure on my 200-acre farm. The enclosure is divided into 25- and 10-acre sections connected with gates. This division lets me conduct isolated studies. The facility has a variety of habitats including open mast-producing hardwoods, brush lots, a running stream, a pond, an apple orchard and 10 food plots containing various forages. The enclosure’s deer population is kept to 15 whitetails. No hunting is allowed in the facility, and the herd’s population is kept low through non-hunting methods. Several behavioral studies have continued since the facility was built. One of the more interesting studies, started in 1998, deals with what natural and planted forages whitetails prefer to eat. The whitetail’s natural-food-preference study is in its 10th year. The plantedfood-preference study started in 2001 and is modeled after the natural-habitat analysis. To conduct any study on food preferences in whitetails, you must have habituated or semi-habituated deer. Wild whitetails will not work because you must be able to observe deer from close quarters in nearly natural settings. Some might argue that such studies can be done with the aid of utilization cages. However, after attempting this method for several years, I concluded that utilization cages might tell you how hard a forage is being hit, but they cannot tell you where that food ranks on a deer’s preference list. KEY TO THE STUDY To determine a whitetail’s true preference for specific forages, deer must have a variety of planted and natural foods available. If a variety of food isn't available, any semblance of preference does not exist because deer will eat whatever is available. So, when it comes to the study of preference, having variety is a vital key. ROLE OF NATURAL FOODS Each deer consumes about 1.5 to 2 tons of food per year. The percentage of this food that comes from planted and natural sources is dependent on the habitat of a deer’s home range. In my area, the percentage of farmland to natural habitat is about even. So, about half of a whitetail’s diet should come from natural habitat and the other half from cropland or food plots. To have healthy whitetails, it's critical they have a balanced diet, and without ample preferred browse, that's difficult. With this in mind, I’ve provided natural browse to my deer on a near daily basis to balance what they eat from food plots and the supplemental feed they are provided. In the beginning, I noticed that deer sought certain browse brought to them. That got my attention so much so that in 1998, I had a local welder construct several racks to hold the various browse species I offered my deer. By placing various natural species in the rack’s individual holders, I identified the browse species they preferred most. When the various browse species are placed in the racks, the setup resembles a salad bar. Presenting the browse species that way lets deer indicate which browse species they prefer. Through the years, I've witnessed my whitetail’s reaction to more than 50 natural browse species. When I discover a browse that deer particularly prefer, I have it analyzed by an independent lab for crude protein and fiber. Though much of what I've observed has meshed with published biological reports, there have been some surprises. As reported in my original piece, the biggest surprise deals with the notion that whitetails have the innate ability to select the most nutritious foods. Through the study, I've disproved that theory through lab analyses. I've discovered that many of the browse species deer prefer are not as nutritious as some of the non-preferred browse species, at least from a crude protein and fiber standpoint. For example, the No. 1 preferred browse species for whitetails in western New York during winter is apple, which has a crude protein/fiber level of 4.2 percent and 19.7 percent, respectively. American Beech (considered a starvation food by many biologists) is 4.3 percent/23.6 percent in winter. Though their nutritional values are about the same during that time, most deer will not eat American Beech unless forced to. The bottom line is that like people, deer do not always eat what is best for
Vol. 18, No. 3 /
WHITETAIL NEWS 27