Environmental Engineering Reference
In-Depth Information
empty each area of wildlife and move on, starting with the cheapest, most access-
ible areas and continuing until there are no unexploited areas left. However, several
processes can cause people to travel further to hunt, and teasing out the degree to
which overhunting is the cause of observed changes in the distance travelled is very
tricky (Box 4.3, Crookes
et al
. 2006).
Box 4.3
Changes in wild pig dealer movements over time.
The accounts over 10 years of a wild pig dealer in Sulawesi showed how he had to
travel further and further to obtain supplies of pigs to sell in the market. By 1998
he was travelling for around 24 h as a round-trip to reach the area where his
hunters were based, compared to 18 h 10 years earlier (Figure. 4.2).
Although there were indeed fewer and fewer pigs being caught in forests nearer
to the market, suggesting depletion, other factors were also at play:
●
There was substantial deforestation in the region at the same time, and one
of the two wild pig species is confined to primary forests, hence depletion is
likely to be due not only to hunting but also to habitat destruction.
●
There was a major road improvement during the period, allowing much
quicker travel, so that the dealers could go further with minimal additional
cost, possibly exacerbating the trend to longer journeys over what would
have otherwise been observed.
●
There were substantial profits to be made from pig dealing, so that more and
more dealers and hunters were entering the market at the time. This competi-
tion may have made it worthwhile for the dealer to travel further than others.
30
25
20
15
10
5
0
530 550
570
590 610
630 650
670
690
710
730
750
Mean time taken (mins)
1988
1991-4
1997
Fig. 4.2
The mean time taken to reach the location of wild pig purchases by
one dealer in three time-periods.
