A small forest bird, much loved by trampers for its habit of popping up in the bush to look for insects in their footprints, is making a comeback in the coastal areas of the Abel Tasman National Park.
Work by Project Janszoon and the Department of Conservation to restore and protect taonga species like toutouwai/robin and kākā in the Abel Tasman National Park is showing exciting results, with significant increases in the number and distribution of robins and other rat-sensitive forest birds recorded.
To assess the impact of pest control operations, Project Janszoon has used acoustic monitoring technology to track forest bird population distribution and call rates at over 120 sites since 2019. The results from 2022 demonstrate a remarkable recovery of robins in the park – robins are an indicator species that respond well to predator control – clearly demonstrating that a stringent approach to the control of pest species plays a critical role in restoring and protecting population recovery of forest birds.
When Project Janszoon started, robins and other rat-sensitive birds were mostly only found in the uplands of the park, where rat numbers are naturally lower and small populations of native birds were able to persist.
The recent monitoring results from these areas showed significant increases in call rates from for these populations, suggesting robins have responded well to lower rat numbers following concerted control efforts.
The most exciting gains have been recorded in the lower elevations, where rats tend to reach higher numbers. The 2022 monitoring detected robina at double the number of sites compared to 2019, which suggests robins are establishing new populations in areas towards the coast where they had been previously unable to survive due to rat predation. This equates to an additional 1500ha of habitat within the Park where robins can now be found now compared to just three years ago.
The data is backed up by anecdotal observations of birds by park visitors, volunteers, contractors, and DOC staff doing work in these areas.
Bruce Vander Lee, Project Director, says that the monitoring results show great progress towards the vision of robust populations of key indicator species like robins. “We are at the stage now where we have the data to show our approach to pest control is working. We just need to keep moving forward with targeted predator control to protect those gains for the future.”
Project Janszoon will continue to monitor forest bird populations throughout the Park, and use that information to ensure that the pest control programme is doing all it can to ensure these vulnerable new populations can thrive.
