During winters like the one we just experienced, many of us feel the
need to feed deer, but deer biologists discourage it for many reasons. Decades
of research has clearly shown that supplemental feeding leads to increased risk
of disease, long-term habitat destruction, habituation to humans, alteration of
other deer behavioral patterns, and the demise of the value of deer and
deer-related recreation (
PA Game Commission 2012). With Chronic Wasting Disease
now present in the state, the increased risk of disease transmission from
concentrated feeding activities is one of the most significant reasons not to
feed.
Deer are extremely well-adapted animals and in general don’t need
supplemental winter food. Deer
eat very little in winter, getting by on what
natural foods are available. In good habitat deer enter winter with 2-3 months
of fat reserves and conserve energy by lying up during severe weather. In fact,
feeding deer may lure them away from natural wintering areas, increasing energy
loss. In addition, it can take up to four weeks of feeding on a new food source
for deer to establish the microorganisms in their stomach necessary to obtain
nutrients from that food. Studies in Pennsylvania have documented the death of
wild ruminants from supplemental feeding in winter, a condition known as rumen
acidosis.
So what is a
concerned landowner or hunter to do? Act like a logger and fire up the
chainsaw! Loggers in Pennsylvania are no strangers to feeding deer. Their crews
feed deer every day. Not with corn or bales of hay, but with mechanized tree
cutters and chainsaws. Once the tree hits the ground deer have access to the
tender buds and twigs, called browse, which are generally nipped off within a
matter of weeks. Where there are chainsaws, there's browse.
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| Stump sprouts browsed by deer |
Deer are
referred to as “browsers” meaning twigs, buds, and leaves of trees and shrubs
make up a primary component of their diet. A deer’s system can easily digest
woody browse, and they will feed on it year round. It is the most important
source of deer nutrition. During winter and early spring it is especially
important as most other food sources are unavailable. Deer depend on browse to
get them through the winter months.
Studies have shown that deer are selective feeders and have distinct foraging
preferences. Preferred foods are eaten first, marginal foods are eaten only
after preferred foods become scarce, and starvation foods, those that have
little nutritional value, are eaten when no other choices are available. In
Pennsylvania, work compiled by the Bureau of Forestry and others has shown that
blackgum, oak, basswood, maple, tulip poplar, aspen, hickory, ash, and pin
cherry provide preferred browse. Of the shrubs, dogwood, viburnum, elderberry,
hawthorn, winterberry, sassafras, and raspberry briars are preferred browse.
On average a deer will consume one ton of forage annually. Only the
preferred species of small trees, shrubs, and plants have the ability to
support large numbers of deer in principally wooded habitats, but it must be
present in large quantities. A mature forest provides far less browse than the
young brushy stage that occurs shortly after logging. Mature forests only
produce 50-100 pounds of browse per acre while young forests, known as early
successional habitat, can produce 1,000-2,000 pounds of browse per acre (
QDMA,Whitetail Report 2009). Mature forests are important for providing hard and
soft mast, such as nuts and fruit, but deer need a variety of habitat types and
a diversity of tree age classes. What may have been good deer habitat 15 years
ago is probably poor habitat today.
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| Recently thinned 30 year old woodlot |
All deer habitat management should revolve around a forest cutting
program to create additional woody browse. One important practice is to thin
overcrowded trees. This is a great practice to do in woodlots that are still
relatively young, from age 15 to 50 years of age. The purpose of thinning is to
free desirable trees from neighboring trees competing with it for growing space.
Trees can be thinned to a more desirable spacing by removing poor quality and
less desirable species. Thinning trees in winter will puts tops on the ground
that deer can browse on during lean times. Thinning overcrowded trees also
increases the amount of sunlight reaching the forest floor. This provides ideal
conditions for new seedlings and sprouts to get started. An added benefit of thinning
overcrowded trees is that it improves the overall health and condition of the
woodlot and concentrates growth on the remaining trees.
Another deer habitat management practice that should be utilized to
increase the amount of woody
.jpg) |
| Regeneration harvest in second growing season |
browse is to cut and regenerate mature forests,
referred to as a regeneration harvest. In this case, a new forest is started
from seedlings and sprouts. There are a number of recommended practices
utilized by foresters to regenerate mature forests so be sure to consult with a
forestry professional before proceeding. Regeneration harvests will provide an
abundance of herbaceous vegetation and new succulent sprouts that will flourish
in the full sunlight following cutting. This new growth will not only provide
an abundance of browse but will also provide concealment for a long period of
time, even after the browse has grown out of the deer’s reach. A word of
caution, in many areas deer populations exceed the carrying capacity of the
habitat and regeneration failures can occur in those areas. It may be necessary
to first reduce the deer population in an area before implementing a
regeneration harvest.
This winter has provided us with a tough lesson. Take action today,
consult with a forestry professional and make a plan to create some additional
woody browse on your property or favorite hunting area. Deer and many other
wildlife species will prosper all winter from your efforts.
