In New Zealand, invasive non-native mammals threaten the survival of native species such as the North Island brown kiwi (Apteryx mantelli). At Whangarei Heads, in northern New Zealand, community groups are working with local and national government agencies to protect kiwi populations. The abundance of kiwi there has been monitored since 2001 using annual counts of calls. Trapping of invasive mammals began in 2002, and their relative abundance is assessed from annual capture rates. Capture rates of stoats (Mustela erminea), weasels (M. nivalis), cats (Felis catus), rats (Rattus spp.) and possums (Trichosurus vulpecula) have declined significantly since trapping began, suggesting their abundance has been suppressed. Ferrets (Mustela furo) were already scarce when trapping began, and have been reduced to undetectable levels in most years. Numbers of hedgehogs (Erinaceus europaeus) have shown little response to trapping. Kiwi populations were apparently in decline before pest control began, but have since increased. Kiwi call rates in 2011 were the highest so far recorded at Whangarei Heads. Stoats are considered one of the main threats to kiwi, and our data suggest that kiwi numbers remain low unless stoat abundance is reduced below a catch per unit effort threshold of ~0.1 stoat per trap per year.
|Number of pages||6|
|Publication status||Published - 2012|