Volunteers on the last "conservation holiday" to Blumine Island this season trimmed back undergrowth along tracks, checked traps and recorded a growing native bird population.
Conservation Department staff and three volunteers camped on the reserve island in Queen Charlotte Sound, from April 30 to May 4, as part of an annual project to clear paths around predator traps.
The volunteers noted 10 adult and three young saddlebacks which meant the birds were successfully breeding since being transferred there 18 months ago, DOC ranger Bill Cash.
Staff heard orange-fronted parakeets for the first time on the island.
The trip was a big success and the volunteers' work would make it easier for him to check on the traps every six to eight weeks, Mr Cash said.
"It's a conservation holiday, it enables people who've got other jobs to spend time at a location where they couldn't normally [go] and it feels good to do conservation work.
"They're a big help.
"It was the last trip to Blumine [Island] for the season, and it's good to have more manpower," Mr Cash said.
The volunteers, one from Nelson and two from Christchurch, largely relied on loppers and handsaws to cut back bush and realign tracks for conservation staff.
No predators were found in any of the traps and the bird numbers were a sign of the island's success as a native reserve, Mr Cash said.
"You can tell there's no predators there because of the way the birds behave.
"The bellbirds were singing constantly and the saddlebacks have been breeding.
"They wouldn't be doing that if there were predators like on the mainland.
"In the five years it's been predator free we've only found one male stoat, who probably swam across."
- The Marlborough Express