Control throught Poison
Brodifacoum is an anticoagulant that is typically used to control populations of larger rodents such as rats and possums. The poisoning of invasive mammals has become a common practice in many conservation areas in New Zealand. This photo was taken on Ulva Island and represents one of the steps that have been taken by the New Zealand Department of Conservation in order to control the rat population on the island. The rat population on Ulva Island was thought to have increased to its peak with the establishment of a post office on the island in 1872. In recent years, Ulva Island has been established as an offshore reserve and several steps including a rat elimination program in 1996 and continued monitoring/ elimination efforts have removed the majority of invasive mammalian species from the island. This mammal free environment has made Ulva island a haven for the conservation of endemic bird species such as the saddleback. Unfortunately, while the poison does help control the rat population, Weka have been known to consume the toxin due to their scavenging behavior.
For more information on the rat control on Ulva Island see: