title: Bait aggregation to reduce cost and toxin use in aerial 1080 baiting of small mammal pests in New Zealand.
abstract: BACKGROUND
  The metabolic toxin sodium fluoroacetate ('compound 1080') is widely used for controlling introduced mammalian pests in New Zealand. For large-scale operations, 1080 is distributed aerially in bait to kill brushtail possums (Trichosurus vulpecula Kerr) and ship rats (Rattus rattus L.). While usually successful in reducing pest populations by > 80%, widespread distribution of toxic bait is relatively expensive and raises concerns from some members of the public. Here, trials with spatial aggregation of baits in forested habitats were conducted to determine whether this can reduce toxin usage while maintaining operational efficacy.
  
  
  RESULTS
  When 1080 baits were aggregated into clusters (by hand sowing) or into strips (by precision aerial deployment), indices of possum relative abundance were reduced by 92-100%, compared with 73-100% reductions using conventional aerial broadcasting, while all methods reduced relative abundance indices of rats by 88% or greater. Radio tracking indicated a kill rate of > 90% against possums, regardless of bait distribution method.
  
  
  CONCLUSIONS
  Simply by modifying bait distribution patterns, spatial aggregation can be used to maintain the high encounter rate of pests with 1080 bait that is necessary for operational efficacy, while reducing current toxin usage by up to 80%. Aggregated bait delivery could have relevance for other mammalian pest control scenarios internationally.
authors.affiliation: Landcare Research, Lincoln, New Zealand. nugentg@landcareresearch.co.nz
authors.forename: Graham
authors.initials: G
authors.lastname: Nugent
authors.forename: Bruce
authors.initials: B
authors.lastname: Warburton
authors.forename: Caroline
authors.initials: C
authors.lastname: Thomson
authors.forename: Martin L
authors.initials: ML
authors.lastname: Cross
authors.forename: Morgan C
authors.initials: MC
authors.lastname: Coleman
mesh_terms: D000818:Animals; D005463:Fluoroacetates / Q000191:economics / Q000378:metabolism / Q000633:toxicity*; D009520:New Zealand; D010571:Pest Control / Q000191:economics* / Q000379:methods*; D010575:Pesticides / Q000191:economics / Q000378:metabolism / Q000633:toxicity*; D051381:Rats / Q000378:metabolism; D048330:Trichosurus / Q000378:metabolism
chemical_list: D005463:Fluoroacetates; D010575:Pesticides; C014815:fluoroacetic acid