By Kip Adams
Quality deer management is a familiar term
to many deer hunters today. You can’t pick up a hunting magazine or watch the
Outdoor Channel without seeing or hearing about it. Although hunters are more
educated than before, many still don’t fully understand QDM or how to practice
it most effectively. One of the most common misconceptions is that QDM requires
shooting as many does as possible. Read on to find out why that's not true —
and how a better understanding of QDM can benefit you as a deer hunter and
manager.
Quality
deer management is an approach that unites landowners, hunters and resource
managers in a common goal of producing healthy deer herds with balanced adult
sex ratios and age structures. In simplest terms, QDM involves balancing a deer
herd with its habitat and having deer — bucks and does — in multiple age classes.
Balancing a herd with its habitat requires determining the appropriate density
or number of deer relative to the available habitat, and then harvesting the
appropriate number of does to achieve that density. Harvest too few, and the
herd will quickly exceed or remain higher than what the habitat can support.
This situation is not good for the deer herd, habitat or other wildlife
species. Harvest too many, and the deer herd will decrease well below what the
habitat can support and unnecessarily remove animals that could provide viewing
or harvesting opportunities. In their infancy, many QDM programs had nearly
unrestricted doe harvests.
The adage, “Shoot as many does as you can, and then shoot three more” was commonly stated. This approach was advocated by many biologists after years of inadequate doe harvests that had resulted in overabundant deer herds and habitat degradation. In fact, from 1985 to 2000, the nationwide whitetail population essentially doubled from around 15 million to more than 30 million animals. Although aggressive doe harvests work well when deer numbers are high and the habitat is productive, when practiced long term in less than optimal habitats, they can reduce deer herds to less than what the habitat can support and lower than levels that provide many hunters with a quality hunting experience. A contributing factor is that as deer numbers increased the past two decades, so did the populations of whitetail predators. Early research suggested that, with few exceptions, predators such as coyotes, bobcats and black bears took so few animals that they had a minimal impact on overall deer populations.
However, now that many deer herds have been
reduced and predator numbers have increased, predators have the potential to
affect deer densities and therefore the number of does we should harvest. That
doesn’t mean we should declare war on predators or stop shooting does. Rather,
it emphasizes the need to determine the number of does to harvest on a
site-specific basis. Across most of the whitetail’s range, deer herds recruit
an average of slightly fewer than one fawn per adult doe. Does drop more fawns
than this, but some die from malnutrition, disease, predation and other factors
before they are “recruited” into the population at about six months old. In the
highly productive Midwest, fawn recruitment rates can average well more than
one fawn per doe. Conversely, fawn-recruitment rates can average 0.2 fawns per
doe in southern Texas during dry years.
At
that rate, it takes five does to recruit one fawn. Obviously, doe harvest rates
must be adjusted accordingly unless herd reduction is desired. So, how many
does should you harvest? Some situations warrant as many as possible, but
others require very few or none. Many properties under QDM guidelines begin to
achieve their initial antlerless harvest goal during the same period they
establish food plots and improve the natural habitat. This combination improves
deer herd productivity, and the antlerless harvest must increase or remain
high.
Conversely,
there are some areas where aggressive doe harvests are not justified. Possible
reasons can include poor-quality habitat, a low fawn-recruitment rate, severe
winter or drought conditions, or overharvesting in previous years. A target doe
harvest depends on many variables, including deer density, property size,
habitat quality, adult sex ratio, neighboring management practices, age
structure of the doe population, your deer management goals, seasonal
conditions — such as extreme winter weather or summer drought — hemorrhagic or other
disease outbreaks (such as many states experienced in 2007), and the
fawn-recruitment rate, which can be a function of the density of predators in
your area. The appropriate doe harvest rate varies by region. For example, the
average property in Florida cannot withstand a comparable doe harvest to the
average property in Illinois. The appropriate harvest rate also varies locally.
For properties with comparable density goals, one with low-quality habitat will
likely have a lower target harvest than a property with high-quality habitat,
even if the properties are only a few miles apart. This point is obvious, but
it shows there is not an “exact” harvest rate that can be applied to a specific
location or region. Fortunately, we can calculate a target doe harvest from
survey data or use ballpark harvest rates. The key is to collect enough harvest
and observation data to refine the target harvest in future years. If you have
a deer density estimate, a general rule of thumb is that harvesting 20 percent
to 30 percent of the does will stabilize the herd. If you do not have a deer
density estimate, there are some general harvest guidelines that can help
determine your target doe harvest.
Whether
you’re in Alabama, Minnesota or somewhere in between, poor habitats can’t
support as many deer as good habitats. With that in mind, here are some harvest
figures that can be used as a general guide to stabilize deer herds. Ballpark
rates in poor habitats range from harvesting one adult doe for every 300 to
600-plus acres. Ballpark rates for moderate quality habitats range from one
adult doe for every 100 to 300 acres, and ballpark rates for good habitats range
from harvesting one adult doe for every 25 to 100 acres. Higher harvest rates
will cause herd reduction, and lower rates will allow herd growth. Harvest
rates for fawns can also be calculated. Ballpark rates for doe fawns range from
one for every 100 to 640-plus acres, and you should harvest as few buck fawns
as possible. Quality Deer Management recommends buck fawns constitute less than
10 percent of the total antlerless harvest (does and fawns combined). In
reality, fawn target rates can vary widely. In some northern environments with
low-density herds and extreme winter conditions, fawns might be specifically targeted
for harvest over adult does because of their lower productivity and higher
winter-mortality rates. In some areas, a few doe fawns are targeted for harvest
so managers can collect important biological information on that segment of the
population.
Additionally,
in some urban and suburban areas with high deer densities and even higher
deer-human conflicts, all antlerless deer — fawns and adults — are targeted for
harvest. What does this mean for your management program? The first step is to
assess where the deer herd is relative to what the habitat can support. Do you
have preferred tree species regenerating in the understory? Are the understory
and shrub layers healthy? Does your harvest data indicate the deer are healthy
and not nutritionally stressed? If you answered “yes” to these questions, the
herd is likely in balance with the habitat, and your goal might be to maintain
the current density. If you answered “no,” the deer herd is likely higher than
the appropriate number for the habitat, and you should consider reducing it.
After you determine where the herd is relative to the habitat, you can
calculate a target doe harvest from the aforementioned figures. The key is to
continue monitoring the deer herd and habitat and adjust future doe harvests
accordingly. So, do QDM programs require you to shoot as many does as possible?
Not necessarily. Instead, they are determined on a site-specific basis and
might range from none to as many as possible. Local conditions and data will
dictate that number and help maintain your deer herd and habitat in a healthy
condition. Just as it was improper to provide blanket protection to does during
the pre-QDM era, it is equally improper to blindly harvest them today without a
clear understanding of local conditions. Fortunately, research provides the information
necessary to guide our management decisions, and when practiced properly, a
QDM-managed herd will provide better deer, better deer habitat and better deer
hunting.
