Numbers of the southern New Zealand dotterel/tūturiwhatu have declined by 19 per cent since last year despite continued predator control efforts, a Department of Conservation survey found.
Doc ranger Daniel Cocker said the numbers highlighted the precarious position of the bird, which is only found on Stewart Island/Rakiura.
“Southern dotterels have spent the past few decades on the brink of extinction and sadly this year looks to be a similar story.
“Without our control efforts, it’s frightening to think just how low the numbers would be.”
The number one cause of decline was predation by feral cats. During the recent breeding season, 32 feral cats were killed by the team across the breeding sites.
Adult dotterels were known to defend nests and chicks, making them easy targets for predators.
“We believe at least 41 adult birds died over the 2023 breeding season. This was partially offset by this year’s surviving chicks, meaning an estimated population reduction of 25 birds.”
The team would now review predator control strategies as part of an adaptive management programme.
Despite this year’s low numbers, the team remained hopeful for a turnaround in the dotterels’ fortunes.
“In 1992, the population reached an all-time low of 62 birds but bounced back to 290 birds in 2009. Given the right conditions, dotterels can be very resilient, and produce multiple chicks per year.”
Southern dotterels were once widespread throughout the South Island and Rakiura was their last refuge.
"It is an uphill battle but it’s one worth pursuing.”
