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DAYLIGHT MOBILE SURVEY FOR DEER

A daylight mobile survey can often be used to estimate deer density and population trends. Mobile surveys may be utilized in areas where its accuracy has been proven and other surveys are less desirable. A mobile survey is conducted by first establishing a chosen route.

This route should be as long as possible up to 15 miles.
The chosen route will be conducted annually and in precisely the same manner; therefore, a number of considerations must be made.
Will the route be passable during wet years? Does the route adequately cover the deer habitat on the ranch?
Will the data be biased by excluding the lower deer populated areas of the ranch?
This survey method works best with two people in one vehicle, the driver and an observer.
The driver is responsible for following the chosen route and counting deer on the driver�s side of the vehicle.

The survey should be driven slowly (8-10 mph) so all deer can be seen.
The observer is responsible for observations from the passenger side and recording of data. Data forms have the route divided by miles and deer observed are recorded by the mile in which they are observed.

The survey line is run in the evening. Starting time depends upon the length of the line. The line should be completed between sundown and dark, however, it should be light enough to still identify deer when you reach the end of the line. If herd composition data is collected during a survey, binoculars or a spotting scope should be used to positively identify the deer.During the first survey a visibility estimate will be made.

The visibility is determined by estimating how far a deer could be seen at right angles to the vehicle every tenth of a mile. The maximum distance that can be estimated is 250 yards on either side. This estimate is used to calculate the acres of visibility on the route.

This acre value divided by the number of deer seen on the route will determine the acres per deer estimate. The visibility of the line is taken only once unless major changes occur along the route that affects the distance deer can be seen.

GUIDELINES FOR CONDUCTING DAYLIGHT MOBILE SURVEYS

1. Survey must have a minimum of 250 acres visibility.
2. Line can be any length up to 10 miles.
3. The line should be completed just before dark.
4. Survey must be conducted four times during August.
5. Deer seen farther than 250 yards should not be counted.

                                       SPOTLIGHT SURVEYS FOR DEER

Spotlight surveys are commonly used to estimate the deer density on ranches.   It is one of the most accurate deer census techniques and, therefore, will be utilized when possible.
A spotlight survey is conducted by first establishing a chosen route. This route can be as long as 15 miles. The chosen route will be conducted annually and in precisely the same manner; therefore, a number of considerations must be made. Will the route be passable during wet years? Does the route adequately cover the deer habitat on the ranch? Will the data be biased by excluding the lower deer populated areas of the ranch?

A survey is conducted with a driver and two observers. The survey should be driven slowly (8-10 mph) so all deer can be seen.   The driver is responsible for following the chosen route and recording observations. Data forms have the route divided by miles and deer observed are recorded by the mile in which they are observed. The observers, using spotlights and riding on the back of the pickup, are responsible for observations on their side of the vehicle. No attempt should be made to identify deer as doe, buck, or fawn. Just the total number of deer observed is recorded.
During the first survey a visibility estimate will be made. The visibility is determined by estimating how far a deer could be seen at right angles to the vehicle every tenth of a mile. The maximum distance that can be estimated is 250 yards on either side. This estimate is used to calculate the acres of visibility on the route. This acre value divided by the number of deer seen on the route will determine the acres per deer estimate.   The visibility of the line is taken only once unless major changes occur along the route that affects the distance deer can be seen.

GUIDELINES FOR CONDUCTING SPOTLIGHT SURVEYS

1. Line can be any length from 2 to 15 miles.
2. Surveys must be conducted four times during August.
3. Surveys must have a minimum of 250 acres of visibility.
4. Deer seen farther than 250 yards should not be counted.
5. Always call the Sheriff�s Office at 512-798-2121 before beginning each spotlight run.

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