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

The number of permits (or checked hunters past a point) can be estimated by

Permits = Number to be Harvested/Probable success

P = N/S

P = 400 / 0.20 = 2000

If poaching, K, occurs, then "number to be harvested", N, needs to be reduced.

Number to be Harvested = No. to be Harvested x (1.0-K)

Where poaching, K, is about 0.30, then

H = N (1.0-K)

H = 400 (1.0-0.30) = 400 x 0.70 = 280

When H is 280, the permits are reduced as in:

P = 280 / 0.20 = 1400

Rearranging, and using other representative numbers:

Number to be Harvested = (Permits) (Success) (1 - Poaching Loss)

For example:

1000 = (3496) (0.22) (1.0 - 0.30)

Crippling also removes animals during hunting (or even research activities). These losses are estimated by "dead-deer" type surveys. Hunter reports can also be used -- those of game hit but not taken. Crippling is expressed as a proportion of the reported harvest. For example, the loss may be 0.25. Thus:

Number to be Harvested = (Permits) (Success) (1.0 + Poaching Loss + Crippling Loss)

For example:

1000 = (Permits) (0.22) (1.0 + 0.3 + 0.2)

1000 = 0.341 Permits

Permits = 2933

The harvest (and permits) can be increased by reducing poaching, reducing crippling, and reducing hunter success (as by using primitive weapons). Influencing these three "hunter" rates must be part of the manager's responsibilities for decisions and actions.

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