The threat of Kawau Island wallabies
The effects of the wallabies' browsing can be seen everywhere and threaten Kawau's significant ecological values.
Wallaby damage to kanuka forest
understorey on Kawau Island
There is little under storey in Kawau's kanuka forests and few remaining patches of broadleaved forest. Heavy browsing stops anything from growing apart from tree ferns and introduced species like Arum lilies. In hard times wallabies even eat leaf litter so bare ground is common. Kawau's native forest will not regenerate unless wallabies are either controlled to low densities or eradicated.
Wallabies could also be affecting Kawau's North Island weka and kiwi populations. By removing seedlings and leaf litter, wallabies reduce food sources such as worms and insects for these birds. Kawau supports two thirds of the total population of North Island weka and is the last stronghold of this species.
The lack of forest understorey has also led to rapid storm-water runoff, erosion and loss of skeletal soils into the sea.