pest control

In New Zealand, endemic bat species require conservation management involving suppression of mammalian pest populations to prevent bat population declines. Toxins are frequently used to control mammalian pests; however, lesser short-tailed bats (Mystacina tuberculata) are also susceptible to poisoning due to their unique forest floor foraging behaviour and willingness to sample different types of bait. Self-resetting traps may offer a suitable alternative to the use of toxins for control of rats if they do not also present a by-kill risk to bats.

Introduced house mice are widespread in Aotearoa/New Zealand, and they have significant impacts on native wildlife. The most common toxins for controlling rodents are anticoagulant rodenticides (AR). Even though AR are an efficient tool, resistance to these substances in rodent populations has been detected in many countries. This phenomenon represents a major factor in reducing the success of pest management, and it is mostly related to missense mutations in the VKORC1 gene.

Predation by introduced mammals is considered a primary threat to New Zealand’s native frog populations. Rats are known predators of the terrestrial Archey’s frog (Leiopelma archeyi), New Zealand’s smallest Leiopelmatid frog. During a 12 year study in Whareorino Conservation Area, we investigated effects of sustained rat control on survival, number of independent juveniles per adult, and abundance of Archey’s frog. Frogs were monitored following a capture-recapture robust design at four grids, split between a 300-ha ‘nontreatment’ area and a 300-ha rat control ‘treatment’ area.