Table 2.
Results from the deer–possum–TB simulation model under five control scenarios. Results are means of 5000 replicate simulations, run for 20 years with possum population control in years 1, 6 and 11
| Control scenario | Possums | Deer to possum back transmission and TB re-establishment events (spillback)‡ | Deer | ||||
|---|---|---|---|---|---|---|---|
| Years to eradicate TB* | No. control operations† | Population density (km−2)* | Years to eradicate TB* | No. control operations | Population density (km−2)§ | ||
| 1 | n.a. | 0 | 652 | n.a. | n.a. | 0 | 11·4 |
| 2 | 7 | 3 | 25 | 0·059 | 14·1 | 0 | 10·3 |
| 3 | 7 | 3 | 25 | 0·015 | 12·3 | 1 | 0·8 |
| 4 | 7 | 3 | 25 | 0·034 | 13·2 | 5 | 1·6 |
| 5 | 7 | 3 | 25 | 0·031 | 13·2 | 5 | 4·3 |
n.a., Not applicable.
*
Assessed over years since initial possum control.
†
Total cost of three aerial possum control operations = NZ$ 7600/km2.
‡
Number of events from time TB eradicated from possums to time TB eradicated from deer.
§
Assessed over 20 years of simulation.