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T.R. Michels
Understanding Fall Deer Movement
By T.R. Michels
Nov 6, 2005, 06:47
 

How Seasonal Changes Affect Fall Deer Movement

     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;

  1. Comfort
  2. Security
  3. Predatory Behavior (natural predators and hunting)
  4. Food Availability
  5. Travel Distance
  6. Breeding Behavior
  7. 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 sources.

     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 activities.

     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.

Breeding Behavior
     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 and T.R.'s Hunting Tips at www.TRMichels.com. If you have questions about whitetails log on to the T.R.'s Tips 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 Addict's Manual.
 
For a catalog of books and other hunting products contact: T.R. Michels, Trinity Mountain Outdoors, E-mail: TRMichels@yahoo.com , Web Site: www.TRMichels.com.

 

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