A Rancher's Guide for Monitoring Elk, Deer, and Pronghorn Antelope Populations

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Much emphasis is put on the positive and negative effects of agricultural operations on wildlife populations. This publication de- scribes a simple, accurate and eco- nomical method for use by ranch operators to monitor deer, elk and pronghorn antelope populations. The collected data reflect the amount of change in the population from year to year. This change is referred to as the “trend” of the population.

A trend is different from a popula- tion estimate. A population estimate is the total number of animals on  the range. A trend indicates whether the population is increasing, de- creasing or remaining stable. Trends are most valuable when averaged over a several-year period. Any one year may not reflect population changes.

The trend of the wildlife popula- tion may be used to indicate poten- tial impacts on habitat. It may also be utilized to help determine proper harvest of big game species. Ranch- ers involved in fee hunting opera- tions need to know if their harvest program is increasing or decreasing the population. Over a period of years, the trend of deer, elk or ante- lope populations is a good indicator of the productivity and related sta- bility of herds.

Trend data collected over several years may be useful during agency- rancher consultations. Often land management agencies decrease livestock density when range forage is over-utilized. Population trend data may be used to indicate whether the over-utilization is the result of livestock or an increasing game population. Properly col- lected, trend data may indicate whether subsequent management should involve livestock stocking adjustments or changes in game harvest.

This MontGuide describes two types of surveys. Both the track count survey and the observation survey have advantages and disad- vantages. In deciding which survey is best for you, consider the assump- tions and methodology of each.

Select the method you believe will give the most accurate information while considering the unique aspects of your particular ranch.

Track Count Survey

Track counts are reliable indica- tors of population trends. The under- lying assumption is that the number of tracks increases proportionally to an increase in population. If the population decreases, the number of tracks decreases proportionally. This is a very simple and economical  way to monitor populations of deer, elk and pronghorn antelope. However, to successfully gather informa- tion that will be comparable from year to year, you must adhere to two basic rules:

1. Keep the survey simple. The person who succeeds you in con- ducting the survey may not be as interested as you. A survey that takes minimum time and effort is much more likely to be conducted annually. Also, as the survey be- comes more complicated, the vari- ability between observers becomes more significant in terms of
2. Keep the survey consistent. If you make changes in the route, time or season the survey is con- ducted, or the mode of conducting it, the information obtained will not be comparable between years. Be- cause these are trend counts, the methodology must be

The following track survey was designed to monitor deer population trends. The same steps apply in use of this system to monitor elk or pronghorn antelope populations.

Time of Year

If possible, the survey should be conducted after a snowfall. Select a four-week period when snowfall is likely to be sufficient for observa- tion of tracks along a route. Survey- ing during periods with snow cover:

1. Allows collection of more
2. Reduces variability in observer skill.

3. Eliminates bias associated with track observations on bare

Conduct the survey on the first three mornings after a snowfall during the selected four-week pe- riod. Observed tracks should be marked or brushed out, so they will not be recounted the following day.

Obviously, in areas where snow- fall is limited or non-existent, the survey will have to be conducted on bare ground. Data collection will be reduced, and the accuracy of the method is somewhat less. If roads are sandy, and tracks can be ob- served easily, then the loss of accu- racy is less significant. Many areas where antelope are present have a lack of snow. However, these same areas usually have sandy roads. It is highly recommended that these roads be dragged with a bushy tree or old bedsprings the day before each survey is conducted. If the survey is to be conducted on bare ground, the survey days selected should be in close succession and in spring at a time when roads are not frozen. Observed tracks should be marked or brushed out so they will not be recounted the following day.

Time of Day

The survey should be started one hour after sunrise. This allows de- tecting animal movement the morn- ing of the survey and also provides time to conduct the survey before snow-melt makes fresh tracks diffi- cult to distinguish from old ones.

Selecting the Route

Select a 10-mile route. These do not have to be successive miles. You can select areas deer normally uti- lize every year and skip areas where deer are rarely found. The beginning point and ending point of each seg- ment must have identifiable fea- tures. The route you select must be the same each year.

Mode of Travel

Automobile travel is recom- mended. The route can be covered in less time in an automobile than on foot or horseback. In addition, continuation of the survey is more likely if successors can follow roads in the comfort of a vehicle.

If it is necessary to travel by foot, horseback or snowmobile, the route must be clearly marked and more time allotted for the survey.

What to Count

Count the sets of tracks that cross the survey route. Deer, elk or ante- lope entering and leaving the road without crossing are not counted.

Deer, elk or antelope walking down the road but not crossing until they are beyond the designated route segment are not counted. Deer, elk or antelope that cross the route sev- eral times are counted several times. Remember, consistency from year to year is the goal. Try to eliminate variation between observers.

Observers should try to differen- tiate deer, elk or antelope from other animal tracks. In areas where hogs, sheep, deer, elk, antelope and other animals occur with each other, ob- servers should be familiar with track and track-pattern differences to minimize mistakes.

As a minimum, run this survey three days in close succession each year. The more days surveyed, the more accurate the data will be.

Number of Observers

One person can normally survey the route alone under snow condi- tions. It may be necessary for a driver to concentrate on driving and a passenger to observe tracks. This is fine if the same procedure is fol- lowed every year. If a passenger and driver do the survey the first year, there must be both observers in all succeeding years. It should also be specified if only the passenger or both the passenger and the driver observe tracks. Either method can be used, but it must remain consis- tent year after year.

Checking for tracks on a sandy road is easier if an observer rides on the hood of the vehicle. Obvious safety considerations make this a hazardous choice and should only be used with sufficient precautions.

What to Record

In addition to the actual number of tracks, several things must be recorded the day the survey is con- ducted. The sample “Track Count Tally Sheet” (Appendix A) provides a format for entering this informa- tion. Most of the sheet is self-ex- planatory. A “Remarks” space is provided to include unforeseen events such as breakdowns, delays and elaborations.

A column is provided for seg- ments of the route. These may rep- resent one-mile increments if the route is continuous, or it may be the segment number if the route contin- ues intermittently. The segment beginning and ending points should be clearly identified along the route and described in detail on a route information sheet.

Each time tracks are observed, the segment in which they occur, as well as the number of tracks observed, should be recorded.

A “Track Route Information Sheet” (Appendix A) must also be prepared as a permanent record of survey methodology. The “Descrip- tion of Route” section is very impor- tant. If the permanent markers along the route are lost, the recorded infor- mation should be sufficient to re- establish both the route itself and  the segments. In addition to a map, include descriptions of permanent natural and man-made characteris- tics such as road crossings, promi- nent trees and outcroppings.

The “Track Route Information Sheet” will also be the permanent, record of the survey itself. Each year record the result of each of the three surveys and the average tracks ob- served.

Supplementary Route

Initially you may be tempted to increase the length of the survey route or the number of days it is conducted. This is fine,  but make it a supplement to the basic survey route. Also, to avoid confusion, keep the records separate from those of the basic survey route. This is rec- ommended because individuals often start a population monitoring program with much enthusiasm, which has a tendency to wane when time, effort and monetary conflicts arise. It is much better to have a supplementary route that can be conducted, when possible, or aban- doned without jeopardizing the entire monitoring program.

Observation Survey

The same basic principles apply to observation surveys that were outlined for the track survey. Again it is important to emphasize simplic- ity and consistency. Observation surveys can be used to monitor deer, elk and antelope populations.

An observation survey can be conducted instead of, or in addition to, track count surveys. The obser- vation survey also gives a popula- tion trend, not an absolute number.

The observation survey has some advantages and disadvantages. The big advantage is that observation of animals is more interesting to con- duct than a track survey. Other ad- vantages are: it does not require ground cover conducive to track sightings, and it allows a sex and age ratio to be determined at the same time the population trend is being obtained.

Disadvantages include: less data collection because the animals must be observed, and a loss of accuracy results from the variation among observers in their skill of spotting animals. The second disadvantage can be minimized by selecting expe- rienced observers and using the same persons whenever possible.

Time of Year

August is the best time to observe animals if a sex and age ratio is desired. Fawns and calves are mov- ing with adults, and adult males are easily distinguished from adult fe- males at that time.

If total population trend is the primary consideration, maximum observations of adult and yearling animals can be made in December and January. This will give an index of adults, but it does not give infor- mation of fawn or calf drop.

If only one survey can be con- ducted, the August survey is recom- mended. Observation surveys should be conducted on at least four days in close succession.

Do not conduct surveys when a storm, minimum visibility or an- other weather extreme occurs.

Time of Day

The survey should be started a quarter of an hour before sunrise. Animals are usually feeding during this period and are most easily ob- served.

Selecting the Route

Select a 15-mile route. They do not have to be successive miles, but remember to count only animals you observe while you are within the designated route segments.

Mode of Travel

Automobile travel at approxi- mately 15 miles per hour is recom- mended. Observations can be con- ducted from horseback or on foot, but these are normally not as effi- cient in terms of time spent and information collected.

What to Count

Count only the animals you see while you are within the route seg- ment. Do not count animals twice, and do not use binoculars to in- crease counts. You may use binocu- lars to determine sex or age of ani- mals spotted with the unaided eye. Remember, try for consistency from year to year.

Keep records of numbers of fe- males, males, this year’s fawns or calves and unknowns observed (sex and/or age not determined).

As a minimum, run the observa- tion route four days in close succes- sion each year. The more days sur- veyed, the more accurate the data will be.

Number of Observers

Two persons (driver and passen- ger) are recommended as observers. Remember, the same number of observers must be utilized every year or results are not comparable between years. To minimize vari- ability, use the same observers each year if possible.

What to Record

The “Observation Route Tally Sheet” (Appendix B) is similar to that used for the track count. Num- bers of females, males, fawns or calves, and unknowns are recorded along with weather, information and remarks.

The “Observation Route Informa- tion Sheet” (Appendix B) is also similar to that used for the track survey. Columns for sex and age are included.

Using the Information

Comparison of the information collected in different years will indicate whether the population is up, down or stable.

The first year’s survey provides base data, but will not provide any immediate information on the trend of the herd. However, sex and age ratio information can be determined from observation data, and concen- tration areas relative to the entire route can be determined from either track or observation route data.

The second year the survey is conducted, a determination of the trend of the herd can be made. The percentage change in tracks or ob- servations from the previous year could indicate the change in the population. Remember that trend data is most valuable over several years. In any one year, counts may fluctuate due to precipitation, snow, etc.

Example

On a basic observation survey conducted in 1993, an average of 50 deer were observed for the four days.

The following year, 1994, the basic observation survey resulted in an average of 55 deer observed each day.

In the example above, the infor- mation indicates the herd increased 10% from 1993 to 1994. The num- ber of does observed increased 35.29%, the number of bucks ob- served decreased 22.2% and the number of fawns and unidentified observations did not change.

Wildlife management decisions resulting from trend information are entirely dependent upon condi- tions within a given area. If over- browsing conditions exist, and the survey indicates the population is increasing, it may be wise to look into a herd reduction program. In another area, where a historically over-harvested population exists, an increasing trend might indicate the response of the herd to under- utilized habitat.