Feral cats have been blamed for a 19% decline in Stewart Island/Rakiura's critically endangered southern New Zealand dotterel/tūturiwhatu population.

The Department of Conservation's (DOC) recently completed annual flock count found an estimated total of only 101 birds remaining.

Last years count totalled 126. 

The southern New Zealand dotterel is considered one of New Zealand’s rarest birds but has suffered ongoing predation despite an extensive feral cat trapping programme. 

DOC Ranger Daniel Cocker says the numbers highlight the precarious position this population is in, despite continued predator control efforts. 

“Southern dotterels, which only breed on Stewart Island/Rakiura, 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.” 

Cocker said dotterels faced a range of threats, but the number one cause of decline is predation by feral cats.

During the recent breeding season, 32 feral cats were killed by the team across the breeding sites, he said.

“Adult dotterels will actively defend nests and chicks, making them easy targets for predators. Dotterels are also curious and easily approached." 

“We believe at least 41 adult birds died over the 2023 breeding season," Cocker said.

"This was partially offset by this year’s surviving chicks, meaning an estimated population reduction of 25 birds.” 

Following this year’s flock counts, the DOC team will review predator control strategies as part of an adaptive management programme. 

Cocker said feral cats roamed large distances and can be wary of the traditional methods to control them, like trapping, hunting and bait stations.

There are limited tools to control feral cats across large areas, he said.

Predator control is only undertaken on a portion of dotterel breeding habitat which is patchy and extends across the full length of Rakiura.

To save more dotterels, more habitat needs to be protected, he said.

Long term solutions require landscape scale change -- this is why initiatives such as Predator Free Rakiura, which aims to remove possums, rats, feral cats and hedgehogs from the island, are so important, Cocker said.

In the meantime, the focus is on effective predator control to hold the line and prevent extinction. 

Despite this year’s low numbers, the team remains hopeful for a turnaround in the dotterels’ fortunes, Cocker said.

“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 is their last refuge."

"It is an uphill battle but it’s one worth pursuing.” 

The New Zealand Nature Fund (NZNF) is supporting DOC’s campaign to save the southern dotterel and has raised over $82,000 from private donors in the past six months.

At 5pm on Tuesday (7 May) at Transport World, NZNF will be launching a campaign to save the Southern Dotterel from extinction.