Native bush robins, or toutouwai, are making a comeback in the lower reaches of the Abel Tasman National Park.
Conservation trust Project Janszoon uses acoustic monitoring technology to track the distribution of forest bird populations in the park.
Director Bruce Vander Lee said the 2022 results show significant increases in robins' call rates - the small forest birds were detected at double the number of sites compared to 2019.
"When we started Project Janszoon, we knew that robins were limited to some of the upper elevation areas where we know that rat densities are lower.
"We are really pleased to see them returning to some of the lowland areas, it lets us know that the hard mahi that everyone is putting into pest control is allowing these robins to return to the places they would have historically been."
He said the landscape scale shift in the birds' distribution showed that the predator control efforts were having a tangible impact.
Vander Lee said robins were popular birds and great ambassadors for New Zealand.
"Anytime you're in the presence of robins, when you stop along the track while you're tramping and one of them turns up, they'll often come right up close to you.
"They're very visible, very curious about what you're doing, it makes a great experience for people visiting New Zealand and visiting the Abel Tasman."
He said Project Janszoon's vision was for people to be able to walk along the Abel Tasman coastline and see the whole range of native species that historically existed there.
Project Janszoon is keen to hear from people who have sighted robins along the coast - which can be done through the Abel Tasman Virtual Visitor Centre app.