Two tiny species of bats who call Auckland home are now critically threatened in the region.
The two types of bats are the pekapeka-tou-poto, northern lesser short-tailed bat (Mystacina tuberculata aupourica) and the pekapeka-tou-roa, long-tailed bat (Chalinolobus tuberculatus). They're the size of a thumb and have the same weight as an AA battery.
Auckland Council, in conjunction with a panel of bat experts, found they were threatened after undertaking the first regional conservation status assessment of the species using the Department of Conservation's New Zealand Threat Classification System.
The short-tailed bat is only known to live on Te Hauturu-ō-Toi/Little Barrier Island within the Auckland region, making the island a national stronghold for this species.
Although the island is free of introduced mammalian predators - which are the main threat to short-tailed bats - this species has been assessed as regionally vulnerable, the assessment found.
The long-tailed bat has been recorded more widely across the region but has also been assessed as regionally critical. It's also threatened by introduced predators, habitat loss, other human impacts, and climate change.
According to the New Zealand Threat Classification System, "critical" is the highest threat ranking.
Councillor Richard Hills, chair of the Planning, Environment and Parks Committee, said understanding how these bat species are doing in the region helps them prioritise conservation efforts and better plan how to protect them.
"This painstaking work done by our passionate staff team and panel of experts is just another slice of the important conservation work happening across Tāmaki Makaurau which also plays a nationally significant role for many vulnerable species."
But even though long-tailed bats have been able to survive on mainland Auckland, more information is needed to protect them, Auckland Council's regional biodiversity advisor Jacinda Woolly said.
"We need to understand more about their roosting areas, flyaway and feeding areas and how they're using the whole landscape so further protection measures can be employed," she said.
"If their key threats are left unmanaged at roost sites, their population will continue to decline, and the potential rate of that decline is of concern."
Auckland Council said increasing interest from mana whenua and community groups about the bats has seen them become a focus for ecological monitoring efforts.
Funding from Auckland Council and local boards has supported community long-tailed bat surveys in Franklin, Waitākere, and Rodney. The Conservation Status Report programme is part of the council's regional biodiversity management obligations under Te Tahua Pūtea Tau 2021-2031 Long-term Plan.
