FACT SHEET AND PROJECT UPDATES
Updated 2016 and 2017
This project makes practical steps to enhance and expand the existing rat baiting program in Norfolk Island National Park. This will reduce direct and indirect impacts of rats on native and significant species and their habitats, including the endangered green parrot and ground-nesting seabirds.
Year 2 update (3-year project)
Overview of progress
- The expansion of the Norfolk Island rat baiting network is complete, with an additional 1000 stations more than doubling the size of the network to 1800 bait stations. Monthly baiting of the extended network is underway.
- Community engagement about rodent control is ongoing, including meetings and presentations with the Norfolk Island National Park Advisory Committee, the Flora and Fauna Society and Wild Mob conservation volunteers.
- Analysis of monitoring data from 2016 on rat activity and bait take revealed a strong seasonal variation in activity levels, likely due to food availability and juvenile recruitment.
- A rat baiting strategy for 2017 has been prepared, aimed at improving bait efficacy. Pre-feeding will occur prior to baiting with the current D3 cholecalciferol bait. Following this a staged bait change will be rolled out across the entire network, using a “first generation” Diphacinone bait. First generation anticoagulant baits pose a low risk of secondary poisoning to non-target species, including the Norfolk Island boobook owl, owing to their short persistence time in living tissue. As rodents need multiple feeds of both the cholecalciferol or first generation baits to ensure a lethal dose, there is a risk that the rat population will develop a resistance to the baits and begin avoiding bait stations if either one is used for lengthy periods of time. Regular bait change will limit these risks.
Overview of progress
- The first phase of the rodent control expansion project was completed in September 2015. This involved cutting rat lines through the Chord forestry section, installing over 300 additional bait stations to the existing rodent baiting network, marking star pickets and data collection.
- Baiting started in October 2015 while further rat lines were cut for phase two of the rodent control expansion project between September and November.
- Community engagement about rodent control has taken place. This includes meetings and presentations with the Norfolk Island National Park Advisory Committee, the Norfolk Island Flora and Fauna Society and Wild Mob conservation volunteers.
- Installation of the phase 2 rat baiting stations and commencement of baiting of these stations are the next steps in the project.
The Threatened Species Commissioner has mobilised $300,000 to expand rodent control in and outside of Norfolk Island National Park, helping to protect the island’s iconic green parrot (Cyanoramphus cookii).
This funding will enhance the rat baiting program across Norfolk Island National Park and expand it beyond the park’s borders. This will complement work to tackle feral cats and substantially reduce direct and indirect impacts of rats on native species and their habitats. The project will:
- increase the number of rodent bait stations across Norfolk Island National Park, including filling gaps in the park’s existing rat baiting network
- expand the existing network of bait stations to incorporate part of the bordering forestry reserve
- establish a program of ongoing servicing and monitoring to cover the expanded bait station network.
This builds on the rodent control program run by Parks Australia which manages Norfolk Island National Park.
This project is one of a suite of measures to protect the green parrot, guided by the Norfolk Island Region Threatened Species Recovery Plan. A range of partners contribute to green parrot protection under the plan, including Parks Australia, Massey University, the Foundation for National Parks and Wildlife, the Parrot Trust of Australia, the Parrot Society of Australia, BirdLife Australia, Island Conservation, the Nature Conservancy, the World Parrot Trust, the Parrot Society of the UK, the Mohamed bin Zayed Species Conservation Fund and Wildmob.
Introduced rodents inhabit many of Australia’s offshore islands and are a major threat to biodiversity. On Norfolk Island, the black rat and the Polynesian rat threaten the endangered green parrot by raiding the nests of this iconic bird, smashing and eating the eggs and killing the chicks.
Over the past 30 years the population of Norfolk Island green parrots has fluctuated dramatically, mostly due to the limited number of suitable nesting sites, competition for nests, and predation by cats and rats. Numbers reached very low levels in 2013, with an estimated 46-93 individuals in the wild and precious few breeding females. A range of partners swung into action to build the population back up, coordinated by Parks Australia through Norfolk Island National Park. Green parrot numbers are once again on the rise and are currently sitting at around 120. This boost to rodent control will protect and build on these gains.
Species to benefit
The Norfolk Island green parrot, plus other threatened species that are impacted by rats on the island, both directly (through predation) or indirectly. These include plant species, endemic land snails, ground-nesting seabirds, and forest birds such as the boobook owl, golden whistler and the scarlet robin.