Action Details

Bait and device coverage and spacing

Facts

  • To achieve high kills it is important that all individuals in a population are put at risk from the control operation.  Individuals can survive operations by being located in gaps resulting from incomplete aerial coverage or in gaps created when ground-laid devices (traps, baits, bait stations) are too far apart.

  • To avoid gaps in aerial operations, all operations must use aircraft (helicopters or fixed-wing) fitted with Global Positioning System units.  If and when available, flow meters should also be used to ensure baits are being sown along all transects.  

  • Swathe width must be determined for each aircraft taking account of both aircraft speed and height, and hopper (bait spreader) used. 

  • For ground operations, spacing between trap or bait lines should not exceed 100 m.

  • To put all individuals at risk, lines should be left for at least 8 nights (see Fig.).  Pre-feeding and placing traps and baits closer together on the line may enable greater spacing between lines, but spacings of greater than 200 m should be avoided.

Graph showing the relationship between percentage kill over time with three different between-line spacings (100 m, 150 m, and 200 m).