The greatest threat facing mainland kiwi populations is predators. Kiwi chicks are especially vulnerable to stoat predation during the first six months of their lives. After this time, the chick is too big – at about one kilogram in weight – for a stoat to kill and it has a high chance of survival.
Over the last two decades, this threat has been managed by removing kiwi eggs from the wild, hatching the chicks in captivity and raising them to a size where they will be able to fight off a stoat attack, before releasing them back into the wild. This technique can be very effective, but it is very expensive and labour-intensive and can only protect kiwi over relatively small areas.
However, trials by DOC in the Tongariro Forest in the central North Island have shown that aerial 1080 operations can protect kiwi populations, as well as other threatened species such as whio and pīwakawaka (fantails) over large areas.