A unit of Lasting Forests Sustained forests; sustained profits evolving since March 30, 1999

1. The primary objectives of wildlife resource seasons:
   1. remove a pre-specified segment of the animal population
   2. achieve humane removals
   3. assure equitable take among participants
   4. assure safety for hunters, landowners, and others
   5. protect landowner rights
   6. maximize a measure of quality-weighted hours of wildlife-related recreation per year
   7. maximize post-season quality-weighted hours of wildlife-related recreation per year
2. Type 4 biological-ecological objectives include:
   1. minimize disturbance of reproductive behavior
   2. maximize females pregnant
   3. maximize size, meat quality, and health of animal taken
   4. minimize range loss
3. A season is primarily a hunting period with designated opening. There are 2 types:
   • end pre-specified
   • end determined when the desired animal units are removed
4. A season includes:
   1. start day
   2. end day
   3. intermediate closure-opening
   4. licenses, tags, and permits issued
   5. weapon and equipment (including dogs)
   6. time during one day (starting time and ending time)
   7. number in possession, in one day, or in a season
   8. treatment of carcass
   9. safety
   10. size, color, character (bearded, antlers), sex of animal
5. Seasons are evidence of adaptive management behavior. Each year slight adjustments are made toward desired ends.
6. Developing predictive equations for season effects seems unlikely. Where H is harvest, and S the days in a season: H = a + bS -- then R², the statistic for the regression equation (a value of 1.o being a perfect fit of the line with all points) will typically be small due to many factors with high variance. There are few ways to gain controls, to replicate. Each year is different. At least one major factor seems to be changed each year, preventing useful comparisons. Multiple regression (including more realistic factors) can usually improve the model.
7. In the future, expert systems will probably be used with artificial intelligence.
8. Generalizations:
   • High harvests occur in the opening days of all seasons. The reversed-J or negative logarithm is a reasonable first approximation for the distribution of the daily harvest.
   • A small peak usually occurs in last days of a long season.
   • Closing a season mid-way (one or two times) can result in small opening-day phenomena.
9. Harvests can often be estimated well by:

   H = a + bH_t - 1 + cH_t - 2

   where

   H = log(Harvest_{t + 1})

10. A running average can also be useful in depicting harvest over time.
11. A phase plane can often be used to study harvests. Plot H against H_{t - 1} for a set of data for at least 6 years.
12. Seasons tend to deal with time; achieving desired objectives require managers to deal with time, location, and benefits likely (or constraints). The harvest is the summation of animals taken and benefits (or both) statewide.
13. Optimum seasons are computed by computing a quality of each day, the probability that any day can achieve the entire set of weighted objectives. Day scores are then summed in various sequences in order to maximize the total score from a set of days in "a season."
14. Seasons need to be as long as possible.
15. Cutting off season length rarely reduces harvests.
16. Excessively long seasons reduce enthusiasm for the hunt. Year-long seasons eliminate opening day phenomena, total harvest, and interest in a game animal.
17. Seasons need to be widespread. People within a region will move from one area to another, following seasons that open as others close.
18. Seasons need to be set early to allow hunters to plan vacations, arrange to be off, etc.
19. Seasons need to avoid major events (crop harvests). To avoid such events is an example of Type 4 objectives.
20. Harvests need to be analyzed in sets of contiguous counties,that is, as regions or management units.
21. Analyze:
    • harvest/area
    • harvest/day
    • harvest/1000 people
    • harvest/ public (a sex, age, race, socio-economic, weapon-carrying sub group)
22. Harvests are a function of weapons used. An animal has a "vulnerability to..." which is the probability of a hunter with a weapon type taking one animal in one day of a season. The lower the vulnerability, the longer may be the season, the more permits issued, etc.
23. Required check-in of animals can yield essential harvest data.
24. Hunter questionnaires can be used, but long delays in responses can produce misinformation.
25. Simulation can be used. Compare: If I remove numbers like I did last year, can the residual population produce (allow) a similar harvest in the next year?

This Web site is maintained by R. H. Giles, Jr.
Last revision January 17, 2000.