6.4 The bounty option
Many people think that introducing a bounty system would be an effective inducement to reduce possum numbers, as well as reducing the need for poisons. It is, therefore, relevant to summarise New Zealand's one and only experience with a possum bounty scheme. During the 10 years 1951-1961, a bounty payment equivalent to approximately $6.00 in 2002 dollars was paid for each possum "token" (the tail plus a bit more skin). During that decade, 12.4 million possums were accounted for, with 4.3 million skins exported and 8.2 million presented for payment of the bounty. The proportion of skins presented for bounty rose from 3% in 1951 to 90% in 1961. After a government payout of about $2 million on bounties (approximately $47 million in 2002 dollars) the scheme was stopped.
Why was the scheme stopped? When the places where the tokens had come from were analysed, it was found that over 75% were being taken from or near farms, picked off roads, or caught in other easily accessible places. During the time the bounty was operating, the harvest of possums from Egmont National Park exceeded one possum per hectare in only one year. This level of harvest was always less than the normal productivity rate of the population. Therefore, losses to the bounty scheme were almost immediately replaced and there was no net conservation benefit.
The fact is that possums living in roadside bushes cause little economic damage, compared with a tuberculous possum next to a cattle farm, or a possum eating kokako eggs. A simple bounty system equally rewards roadside kills and the possum killed on a deer farm or high value conservation area. If the costs and effort are low to kill possums at the roadside, but high in conservation areas where access is difficult, bounties will result in the wrong possums being targeted. When particular objectives are being sought (for Tb control or conservation reasons), the pest population needs to be reduced to the levels that provide that benefit. This is why the AHB and DOC specify the precise areas where they want to manage possum populations, and set desired density targets. In summary, although bounty systems may benefit possum hunters and create employment, they will not effectively reduce possums to the low levels required for Tb control and forest recovery unless the fundamental problem of ineffective targeting can be overcome.