Conservation effort and monitoring of the population size in a fluctuating environment
We consider optimal conservation strategies for endangered
populations. In decision-making of conservation, we must cope with
many kinds of uncertainties in survivorship or population size.
Assumptions are: the survivorship is affected by unpredictable
environmental fluctuation and can be improved by conservation effort,
and the exact value of the initial population size is also unknown.
The conservation strategy involves two aspects: monitoring effort to
improve the estimate of the initial population size and conservation
effort. Both types of effort imply economic costs. The optimal
management strategy minimizes the weighted sum of extinction
probability and the economic cost of the conservation and the
monitoring effort. [1] We first analyze the optimal conservation
effort when the current population size is known accurately. [2]
Next, we consider the situation in which there is limited information
(i.e. a cue) on population size. [3] We subsequently discuss the
cases where the cue accuracy can be improved by monitoring of the
population. Next we discuss multiple year optimization of
conservation effort and monitoring of population size.
Optimal strategy of hunting for deer in Hokkaido
We consider the optimal harvest strategy for deer populations in
Hokkaido. Large deer populations have damaged forests and
agricultural areas. We need to decrease population size to an
appropriate level. First, we consider estimation of population size
of deer in Hokkaido using computer simulation. Next we estimate the
ratio of future population size to that in 1993 in several harvest
scenarios. Because the number of hunters is limited, we also examined
optimal allocation of hunting effort to eastern Hokkaido and
west-central Hokkaido.