Wakatipu rangers and eight volunteers spent 10 days near Paradise, at the head of Lake Wakatipu, on the project, which was designed to find out where the bats roost.
The transmitters were part of the preparation for the rat control programme expected later this year, due to the heavy seeding of beech trees and the rise in rat numbers it will create.
Biodiversity programme manager Barry Lawrence said rats were the major predator of native bats.
"The massive amount of beech seeds now sitting on the forest floor is like a big bowl of muesli for them. Unfortunately, our bats could become the next course."
Mr Lawrence said Doc surveys bat numbers twice each year and a major population decline coincided with the last heavy beech seeding and rise in rat numbers in 2006-07.
"The situation is the same now, so we want to knock back the rats before we lose the bat population from the Wakatipu. To target our efforts, it's essential that we find exactly where the bats live.
"We've been catching them at night when they're out hunting. This is in specially designed bat-friendly traps that look like a big harp set up on the edge of the bush.
"Our surveys show that their main hunting area runs from the Routeburn Flats and up the Dart to Daleys Flat, and in the Rees, to at least the Hunter Stream.
"They've also been recorded by the end of the forest at Kinloch."
Nine bats were caught and radio-tagged with tiny 0.8g transmitters, fixed on to bats weighing around 12 grams.
Staff and volunteers tracked them during the day with radio receivers when they were in their roosts in tree hollows.
"During the 10-day project, five distinct roosting areas were found."
Mr Lawrence said the department now knew where five social groups of bats lived.
"We couldn't have done it without the help and enthusiasm of bat specialist Jane Sedgeley and the dedicated volunteers who gave up a big part of their summer holidays to help us."
