QDMA Articles :
Summer Nutrition
By: Kip Adams
All deer managers realize that deer
have critical nutrient requirements in autumn. Bucks are gearing
up for the rut and does and fawns are adding fat for winter. While
autumn nutrition is important, spring and summer nutritional needs
should not be overlooked. Spring and summer are critical times
for body growth, antler growth, gestation (pregnancy), lactation,
fawn development, and fat deposition. Managers must understand
these seasonal requirements and tailor their nutritional programs
to meet these needs.
Spring
Spring forage is critical for whitetails since adults can lose
15 to 30 percent of their body weight during winter. Rigors of
the rut and winter take their toll on bucks and they are second
only to fawns to succumb to winter mortality. Bucks begin growing
new antlers in spring, but antler growth is secondary until body
resources lost in winter are replenished. Whitetails have a relatively
long gestation (about 200 days) and does have increased nutritional
demands during spring. Although breeding occurs during autumn,
over 80 percent of fetal growth and 90 percent of the energy spent
on gestation occurs during the final trimester. In northern regions,
new antler growth and the last trimester begin in April and correspond
to spring green-up.
Spring foods high in protein and energy are necessary to meet
the increasing nutritional demands. Spring foods include green
leaves and stems of woody and herbaceous plants, leftover mast,
forbs, and legumes. In northern regions, preferred deciduous woody
plants include red, white and black oak, yellow and white birch,
and red maple. Preferred herbaceous plants include Canada mayflower,
raspberry, and blackberry. Preferred mast includes acorns, beechnuts,
apples, crabapples, grapes, and blackberries. Preferred forbs
and legumes include chicory, clover, alfalfa, and trefoil.
Summer
Fawns are born as spring turns to summer. Does now require even
more nutrition as lactation is two to three times more costly
than gestation. Their nutrient-rich milk contains about 78 percent
water, eight percent fat, eight percent protein, five percent
sugar, and one percent ash, and has twice the protein and energy
per unit volume as cow’s milk. Undernourished does still
produce nutrient-rich milk but at reduced rates. Well-nourished
does with twins generally produce 67 percent more milk than does
with single fawns. Fawns have very high energy demands. They weigh
five to 10 pounds at birth, will double their weight within two
weeks, and can triple it within a month. Fawns depend heavily
on their mother’s milk for nutrition the first two to three
months but can survive exclusively on vegetation by around two
months of age.
Maximum antler growth occurs during summer and is directly linked
to nutrition. Bucks with access to high-quality nutrition have
significantly larger antlers than those on poor quality diets.
Minerals are also important for antler growth. Hardened antlers
consist of 54 percent minerals, 45 percent protein, and one percent
fat. Calcium and phosphorus are the most abundant minerals and
occur in a 2:1 ratio. Deer get calcium and phosphorus from their
diet and from reserves in their bones. Bucks store these minerals
prior to the antler growing season for use during summer. A good
way to ensure bucks are receiving enough calcium and phosphorus
is to provide mineral licks. Although there is no scientific data
showing measurable benefits to free-ranging deer, there is evidence
of benefits from the livestock industry. Mineral licks can be
created every 100 to 150 acres and should include a granular mix
(not a block) of calcium and phosphorus in a 2:1 ratio, trace
minerals, and salt (<50% of mix).
Habitat Management
Once managers understand the seasonal needs of their deer herd,
they can begin improving the habitat accordingly. It is important
to realize that property boundaries are meaningless to wildlife.
The habitat quality and management practices on adjacent properties
should be considered before undertaking a habitat management program
on your property. Managing a forest for wildlife requires careful
timing and work over many years. The first step is developing
a forest management plan.
Managers can develop a forest management plan themselves, although
the assistance of a qualified wildlife and forest manager is recommended.
At a minimum, the plan should include the following seven items:
1) Management objectives for the entire property — it is
important these objectives are stated as clearly and specifically
as possible.
2) Maps detailing the property’s location, boundary, and
individual stand types — U.S. Geological Survey topographical
maps are ideal for marking the property’s location. Boundary
and stand maps should show the compass bearings and lengths of
boundaries and be drawn to scale. They should also identify boundaries
and the methods used to mark the corners (e.g., iron pipes, concrete
monuments). Boundary and stand maps should also show the division
of forest stands on the property, the acreages in each stand,
and topographic features such as hills, streams, ponds, swamps,
ledges, and roads.
3) Management goals by stand type — management goals are
specific to each stand and are developed from the management objectives
stated at the beginning of the plan.
4) Stand descriptions — important vegetational characteristics
such as tree species, age, diameter, stand density, volume, quality,
and growth rate of each stand are listed. You should also include
wetlands and other sensitive areas.
5) Site descriptions by stand type — site descriptions include
the stand’s aspect, slope, and site index (i.e., indicator
of site quality).
6) Recommended treatments by stand type — the recommendations
detail the treatments or techniques used to manipulate the habitat
to meet the landowner’s stated objectives. These may include
timber management practices, prescribed burning, mowing, discing,
fertilizing, and applying selective herbicides. 7) Procedures
for updating the plan — most plans should be updated every
five years. A written plan assists managers in improving the existing
habitat, creating new habitat, and provides an element of continuity
if the land changes ownership or managers.
Whether developing a plan individually or with a forester, you
should understand what constitutes quality deer habitat. Good
habitat includes a mosaic of stand types from open ground to mature
forest with a good mix of areas in early succession (young regrowth
after disturbance). The habitat should include several heights,
ages, and species of trees and both forested and open areas interspersed
throughout the property. Edge is the transition area between habitat
types and is an important component of deer habitat. Edge is created
where two or more habitat types meet. Interspersion of habitat
types maximizes the amount of edge and typically provides dense
cover and a variety of different plants.
A property’s potential for deer habitat is not fixed. Forest
management techniques can be used to manipulate vegetation to
increase high-quality deer forage. Clearcuts and seed-tree cuts
create abundant food and cover at ground level. Clearcuts completely
remove the overstory and seed-tree cuts remove most of the overstory
but leave a few trees to help “reseed” the residual
stand. These cuts should be laid out in strips or irregularly-shaped
patches to maximize edge. Available tree species may influence
your harvest method. For example, aspen grows quickly and regenerates
in high density. Aspen provides abundant browse and thick cover
for deer and other wildlife. Aspen regenerates better by stump
sprouts and root suckers following a clearcut than it does from
seed.
Fuelwood cuts or small patch cuts also can create high quality
deer habitat. Cuts should be one to five acres in size and scattered
throughout the property. Brush piles created from slash provide
shelter for deer and other wildlife and will protect new seedlings
from being browsed. Managers can promote stump sprouts and enhance
hardwood leaf production by conducting timber harvests or fuelwood
cuts during winter.
The importance of mast cannot be overstated. Mast is most important
during fall but is also heavily used during spring and summer.
Timber harvesting strategies can be used to increase acorn and
other mast production. Thinning around mast species reduces crown
competition and enables trees to get additional light and nutrients
and produce additional fruits and nuts. You can do this to overstory
oaks and beeches or to smaller apples and persimmons. Pruning
and fertilizing mast species are also useful strategies, as well
as planting additional trees.
Year-round food plots are important. Research suggests a minimum
of one percent of your property needs to be in high-quality food
plots to have a measurable impact on the deer herd. I suggest
planting three to five percent. You can use old fields, logging
roads, log landings, or clear land to create new plots. Like timber
cuts, new plots should be laid out in strips or irregularly-shaped
patches to maximize edge. About 70 percent of the acreage dedicated
to food plots should be planted in cool-season perennials, 10
percent in cool-season annuals, and 20 percent in warm-season
annuals.
Cool-season forages are typically planted in fall through spring
and are utilized in fall through early summer. Warm-season forages
are planted in spring and early summer and are utilized in summer
and fall. Perennials are plant species that live for more than
one year and are more economical and productive than annuals in
the long-term. They are harder to establish and slower growing
than annuals during the first few months and require periodic
mowing, fertilization, and weed control. Annuals live for one
year, are easier to establish than perennials, and produce more
biomass than perennials during the first few months. Annuals need
to be replanted every season and are more expensive and labor
intensive than perennials.
Cool-season perennials include red and white clover, alfalfa,
orchardgrass, timothy, and trefoil.
These species mixed together and/or with cereal grains or other
grasses make great cool-season plots. Planting mixes allows faster-growing
species to act as a nurse crop for slower-growing species that
spend more time developing root systems. Mixes take advantage
of different maturity rates, and provide insurance that at least
some species will be suited to the site and weather conditions
and guard against total crop failure. Mixes containing legumes
fix some of the needed nitrogen and decrease fertilizer costs.
Cool-season annuals include cereal grains such as rye, oats, and
wheat, and brassicas such as turnips, rape, and canola. Brassicas
are high in protein (up to 38 percent), highly digestible, and
extend the growing season into winter. Brassicas are more palatable
to deer after a frost, can stay green under the snow, and should
be included in every food plot program. Warm-season annuals include
corn, soybean, Lablab, millet, sorghum, and peas. Corn is great
since it is used for food and cover. Soybeans and peas are highly
preferred by deer. Deer will heavily browse these species and
you may need to plant more than two acres of each to get any pods.
Food plots are a great way to provide high-quality year-round
nutrition to deer. Be sure to conduct a soil test and lime accordingly
prior to planting.
Water is the final habitat component and deer get water from three
sources:
1) Free water is available from streams, springs, ponds, and as
rain or dew on plants.
2) Preformed water is found within a food source. Hardwood browse
contains about 50 percent water and succulent forage contains
about 70 percent water.
3) Metabolic water is produced within an animal’s body by
the oxidation of carbohydrates, fats, and proteins. Adults need
three to six quarts of water per day but this varies by season.
Deer need more water during summer due to higher temperatures
and lactation. Deer can also concentrate their urine and “dry
out” their feces to conserve water. In northern regions,
deer fulfill much of their water requirements with daily forage.
Spring and summer are a nutritionally demanding period for deer.
It is important for managers to provide enough high-quality forage
to meet those demands. Conducting adequate doe harvests to keep
deer populations in balance with available habitat is the first
step. Natural vegetation management and food plots are next. Applying
a little knowledge and some hard work to the habitat can pay big
dividends to the deer herd.
Kip Adams received his B.S.
in Wildlife and Fisheries Science from Pennsylvania State University
and his M.S. in Wildlife from the University of New Hampshire.
Before becoming QDMA’s Northeast Regional Director, Kip was
the Deer and Bear Project Leader for New Hampshire’s Fish
and Game.
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