Four-year-old Tautahi was the first to make headlines when he was wrangled back into the sanctuary after a jaunt around a farm outside the boundary fence.
Both he and Māhutonga “were promptly tracked and found safe by rangers”, Kākāpō Recovery said.
Māhutonga’s departure leaves four birds - Tautahi, Bunker, Ōtepoti and Taeatanga – at the 3400ha sanctuary between Te Awamutu and Putāruru, out of the original 10 at the beginning of the trial.
The first three birds were removed from Sanctuary Mountain Maungatautari in November, after breaking the two-strike escape rule.
Manaaki and Elwin followed in January after Elwin was discovered by a tanker driver on a rural road.
Māhutonga is the sixth bird to be removed, having been among the first batch of birds to be released into the sanctuary.
Although only 40 per cent of the trial’s birds remained, it was a valuable learning experience for researchers, Kākāpō Recovery said.
“We continue to learn a lot from this trial.
“It’s clear that many of the birds enjoy hanging out near the fence.
“We are very interested to learn why this is, especially when the sanctuary is bigger than the two main kākāpō breeding islands combined.”
The escapes led to several new lines of information gathering, including diet analysis sampling and new ways to monitor the birds.
In the meantime, the remaining quartet have all passed their latest routine health assessments, had their transmitter harnesses checked and GPS tags changed.
Bunker needed a little assistance when found by rangers, however.
“When the rangers were tracking Bunker for his check-up, they first found him a giant tangle of supplejack vines, up in a tree overhanging a bank!
“Luckily for them, he was in a very calm and patient mood, and they were able to catch him safely.
“After passing all his checks, he enjoyed some apple before giving the rangers a giggle with an overdramatic, slow-motion getaway (watch this space for the Oscar-worthy performance!).”
Milly Fullick is a journalist based in Taupō. She joined the Taupō and Tūrangi Herald team in 2022.