There are several factors that determine when
and where deer move during the fall. An understanding of these factors
can explain the reduced sightings of bucks during the hunting season.
These factors fall into seven different categories;
Predatory Behavior (natural predators and hunting)
and Lunar Forces
Fall signals an increase in white-tailed deer
activity, which is brought on by changing food supplies and the rut. In
study by Kammermeyer and Marchinton deer traveled greater average
distances per day during the fall than they did in the summer. Deer
also traveled greater distances per hour during both dawn and dusk in
the fall than they did during the summer. There was also a shift in
daytime deer activity: during the day in the summer the deer were most
active at dusk, from 6 PM to 10 PM; during the day in the fall they
were most active at dawn, from 4 AM to 10 AM, with movement continuing
until noon. Overall, the deer moved more during darkness in the fall
than they did in the summer. This increase in deer movement during
darkness in the fall can be attributed to decreasing hours of daylight
(in some areas from 14 to 8 hours), decreasing foliage as leaves fell
(leaving deer more exposed during daylight hours) and changing food
During the summer deer can feed securely in
wooded areas where there is abundant forage. In the fall deer often
feed more heavily on agricultural crops, and browse in more open areas,
which causes them to feed more at nigh for security reasons. The change
in feeding patterns from summer wooded areas to open fall food sources
forces the deer to travel farther in search of food. I refer to deer
movement from bedding sites to food sources as the "Distance Factor."
In most areas inhabited by whitetails fall
brings significant changes in weather patterns. Barometric pressure and
temperatures fluctuate more, there is more cloud cover, more
precipitation and stronger winds. These changes often combine to create
low temperatures, changes in dewpoints, lower wind-chill factors and
storms. These meteorological changes create a reduction in plant
chlorophyll production, causing some plant food sources to die or
become dormant, leaves to fall, and other food sources to ripen.
As fall approaches and deer begin growing
their heavy winter coats the temperature, precipitation, humidity,
wind, dewpoint, wind-chill, and amount of vegetation and cloud cover
all have the ability to affect the comfort of the deer. I refer to
these meteorological changes as "Comfort Factors." In extreme
conditions meteorological changes may also affect the health of the
deer, and as such they can also be considered as "Security Factors."
Fall Deer Movement Factors
Comfort and Security
During my seven years of research, deer
activity was greatest during the fall in open areas at dawn and dusk,
when the temperature, dewpoint or wind-chill was between 15 and 55
degrees. If the temperature, dewpoint or wind-chill fell below twenty
degrees the deer (including dominant bucks) moved later in the morning
and earlier in the evening than they did in warmer weather; providing
there was cloud cover, fog, or precipitation which reduced the amount
of light during daytime hours. In a Minnesota study Nelson found that
Fall deer migration consistently began after temperatures dropped below
19 degrees Fahrenheit for the first time. Migrations started in each of
14 years when temperatures below 19 degrees Fahrenheit lasted at least
five days. This migration could also account for fewer buck sightings.
Normal daytime deer movement is also
restricted when there are strong winds. During my research the deer
often remained near their bedding areas when there were strong winds.
When they did move they stayed in wooded or low-lying areas and on the
downwind side of hills. Rain or snow in cold weather may be
uncomfortable and cause deer to lose heat; which may cause deer to
restrict their movements. Heavy rain makes it hard for deer to hear and
they restrict their movements. Precipitation of any kind may make it
difficult for deer to see, which may restrict their movements.
Clouds, fog and precipitation all have the
ability to reduce the amount of available light causing daytime
conditions to resemble those at dawn and dusk, when deer feel more
secure. During my studies, precipitation in the form of light rain,
drizzle or snow, and gentle sleet, caused the deer to move earlier in
the evening and stay later in the morning than normal, because of a
lower relative light factor. During heavy rain or snow, and driving
sleet or hail, the deer sought shelter in wooded areas; in coniferous
trees if they were available.
Vegetation, because it also limits visibility,
makes deer feel secure. Abundant vegetation can eliminate enough light
in shaded areas to create the illusion of twilight conditions, when
deer feel secure. But, once the leaves fall, less vegetation allows
deer to see farther, which causes them to feel less secure. I noticed
that after the leaves fell the deer began entering open feeding areas
about a half hour later and leaving them a half hour earlier, than they
had when the leaves where still on. After the leaves were gone there
was more available light in the wooded bedding areas, which caused the
deer to remain in the bedding areas longer. It also caused the deer to
abandon many trails that were now more open to begin using other, more
protected trails along hillsides and gullies, or they moved to trails
that were deeper into cover and offered more security.
High or low temperatures, dewpoints or
wind-chills that make it too hot or too cold; and heavy precipitation
are “Comfort Factors.” Wind speed that affects the ability of the deer
to smell and hear, and to lose heat; heavy precipitation because it can
cause deer to lose heat; and clouds and leaves, because they affect the
ability of the deer to see, are all "Security Factors."
Food and Distance
Deer movement is governed to a great extent by
the availability of food. As food sources become depleted in the fall
deer are forced to travel greater distances to locate new food sources.
They often shift their feeding patterns to take advantage of preferred
foods that ripen or become available during the fall. Depending on how
scattered these available or preferred food sources are, and how close
they are to individual deer core areas, the deer may move more, or
less, than normal. This "Distance Factor" is directly linked to the
"Food Factor" and these two together, because of their importance to
deer survival, can affect how much time is devoted to other fall deer
The availability of preferred food sources may
have a significant affect on dominant buck activity during the rut.
Miller reported less rubbing activity by bucks during a year when there
was low oak mast (acorn) production. The reduction in rubbing activity
may have occurred because the bucks spent more time in search of food
and therefore had less time available for rubbing behavior. This could
lead to fewer buck sightings near traditional rub routes and scrapes
during years of low mast production.
Fewer bucks sightings can also be attributed
to the fact that bucks increase the size of their home ranges during
the fall. This occurs when bucks begin traveling farther from their
Fall core areas as they search for new food sources and does to breed.
During a study by Kammermeyer and Marchinton the average range of bucks
increased from 71 hectares in the summer to 124 hectares in the fall.
In my study in Minnesota the range of bucks increased from 300 acres to
1500 acres. The average daily distance traveled by bucks may also
increase during the rut. Bucks in the boreal forest of eastern Canada
commonly travel 20-25 miles every five to seven days in search of does.
The combination of this "Breeding Factor," and the need to find food
causes increased buck movements, and, depending on the amount of
distance traveled and the time deer spend in specific locations, can
lead to fewer buck sightings.
This article is an excerpt from the Deer Addict's Manual. Volume 3, Fall Deer Movement Influences ($9.95 + $5.00 S&H), by T.R. Michels.
If you are interested in more whitetail hunting tips, or more
whiteatail biology and behavior, click on Trinity Mountain Outdoor News
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message board. To find out when the rut starts, peaks and ends in your
area click on Whitetail Rut Dates Chart. T.R. Michels is a nationally recognized
game researcher/wildlife behaviorist, outdoor writer and speaker. He is
the author of the Whitetail, Elk, Duck & Goose, and Turkey Addict's
Manuals. His latest products are Hunting the Whitetail Rut Phases, the
Complete Whitetail Addict's Manual, the 2005 Revised Edition of the Elk
Addict's Manual; and the 2005 Revised Edition of the Duck & Goose