Monitor the amount of forage inside and outside of the cage. If vegetation growth inside the cage is much higher and more productive than outside the cage, then your deer numbers are likely on the higher side. Photo by Luke Stamper.
I often receive calls from clients after cool- and warm-season plantings who ask, “Why is my food plot not performing as expected?” There is no one-size-fits-all answer for food plots, but in this article, I hope to provide a starting point for observations that you can make to improve the outcome of your forage management program.
One problem with food plots is that biomass is constantly being removed from the area by deer and other critters, leaving land managers with an inaccurate picture of how well the planted area is performing. This is especially true for areas with high deer densities where plant establishment is somewhat nonexistent due to the number of mouths feeding on newly emerged vegetation.
A simple solution to this common problem is to design, construct and install an exclusion cage within the boundaries of your food plot. An exclusion cage is meant to do just as the name suggests — exclude animals from grazing a certain area. The land manager can then compare forage productivity in areas with and without grazing pressure and use the information to make decisions about food preferences.
Exclusion cage designs vary, but there are some general requirements for the exclusion cage to function properly. First, when excluding deer, the caged area must be high enough — roughly 4 to 5 feet — to keep deer from leaning over the side to feed and small enough in diameter to keep deer from jumping inside of the protected area. I personally construct my exclusion cages to cover approximately 16 square feet. Next, the wire material used to construct the exclusion cage should be small enough to keep deer from putting their heads through the side to access forage. In addition, the cage should be securely staked down with rebar or T-posts fastened to the cage by wire or heavy-duty zip ties.
The shape of your exclusion cage isn't that important if you cover the basics I mentioned above. However, circular cages tend to be the easiest and cheapest option because they can be fastened at a single point compared to a square design, which will need to be secured at the four corners.
Exclusion cages can help land managers examine forage selectivity and gain a better understanding of what deer prefer on your property. These exclusion cage demonstrate that sunn hemp, cowpeas and soybeans were eaten.
Once your exclusion cage is installed, you can monitor the amount of forage inside and outside of the cage. If vegetation growth inside the cage is much higher and more productive than outside the cage, then your deer numbers are likely on the higher side. You could remedy this by adjusting your harvest quotas, managing native vegetation and increasing the area of your food plots. If forage heights inside and outside the cage are similar, then the opposite may be occurring.
You can also use exclusion cages to examine forage selectivity by deer and gain a better understanding of what deer prefer on your property. The exclusion cage shown in figures on Page 9 demonstrates that sunn hemp, cowpeas and soybeans were selected first out of the 12-species warm-season blend. This type of insight can help you customize your own blend.
Finally, exclusion cages allow a land manager to assess whether they’ve successfully established a food plot, which may be one of the greatest benefits if you aren’t able to observe the plot on a regular basis. Instead of wondering whether it was fall army worms, lack of moisture, low seeding rates or too much pressure from deer that caused an undersirable outcome, the manager can simply make comparisons inside and out of the established exclusion cages to determine the issue and identify a solution.
It’s never too late to install exclusion cages across your plots. I encourage you to do so and begin monitoring the forage that you worked hard to put in place.