Auckland Zoo has bred and reared lesser short-tailed bat twins - the first time the threatened New Zealand species has been bred and hand-reared in a zoo.
The tiny short-tailed bats (pekapeka), a male and female were born in mid-November weighing just 4 grams, the weight of a 20 cent coin. They are now a healthy adult weight of about 14 grammes.
New Zealand Centre for Conservation Medicine clinical services coordinator Mikaylie Wilson said the mother had given birth to twins before but they did not survive.
"From this experience, we knew she wasn't able to cope with raising two, so the decision was made to pull the first twin at two days, and then at two weeks the second pup was failing to thrive so we pulled it as well.''
Ms Wilson, who has experience hand-rearing bats in Australia, set up a care programme for the bats.
"We had a portable incubator that closely mimicked a nursery in the wild, keeping them warm and secure.
The temperature of the incubator was at 28-29 degrees, and we were feeding them every four hours."
Mikaylie Wilson cared for the bats for five days before training bird keeper Debs Searchfield to play 'mum', feeding and caring for them at home.
Ms Searchfield said it was worth the sleep deprivation.
"Gaining more husbandry skills, hands-on techniques and knowledge will hopefully help the future of this species and other bats in recovery programmes."
The bats' parents are descendants of a population from the Tararua Ranges in the lower North Island. They came from a group that were collected and moved by the Department of Conservation to Kapiti Island, off the Kapiti Coast, almost a decade ago.
However, a fungal ear infection meant the group was not suitable for release and the zoo now displays the only lesser short-tailed bats in captivity.
• An adult short-tailed bat weighs 12-15 grammes, has large pointed ears, a free tail, and uses echolocation to navigate and catch its prey.
• They eat insects, fruit, nectar and pollen and are the only pollinator of the rare native plant, dactylanthus (known as woodrose).
• Their heart rate is 250 -450 beats a minute at rest and 800 beats a minute while flying.
• Unlike most bats, which catch their prey in the air, they have has adapted to ground hunting and spends lots of time on the forest floor, folding their wings to use as "front limbs" for scrambling around.