Persistence of sodium monofluoroacetate (1080) and diphacinone in hen eggs for control of stoats (Mustela erminea)

Hen eggs injected with either sodium monofluoroacetate (1080) or diphacinone are being used by the Department of Conservation for the control of stoats (Mustela erminea ). The eggs remain attractive to stoats for at least 1 month. This study investigates the persistence of the toxins in eggs incubated at two temperatures of 1080 in eggs incubated at both temperatures and the amount of diphacinone in eggs incubated at of diphacinone in eggs incubated at days. More diphacinone could be injected into eggs to compensate for this loss. However, eggs are seldom likely to be exposed to temperatures as high as eggs containing 1080 or diphacinone can be left in bait stations for at least 28 days without loss of efficacy to stoats.