Pest control
Pest control efforts by the Department of Conservation have managed to stabilise some mainland mōhua populations. For example, where biodegradable 1080 poison was used to control rats in the Dart valley, there was a more than 80% survival rate, compared with just 10% in untreated areas. The population of mōhua in the Landsborough valley has increased four-fold since 1998, thanks to an intensive programme of pest control, including aerial 1080. The population is now strong enough for birds to be transferred out to establish a new population on Resolution Island. Similar aerial 1080 operations in the Catlins and the Hurunui, Hawdon and Eglinton valleys have had equally encouraging results. DOC and TBfree New Zealand accounted in March 2014 a significant repopulation in the Catlins of other avian species, including bellbird and tomtit, due to the reduction in predators.