New Zealand long-tailed bat (Chalinolobus tuberculatus)

The New Zealand long‑tailed bat (Chalinolobus tuberculatus) is a small vesper bat endemic to the main islands of New Zealand. Belonging to the family Vespertilionidae, it is the only native terrestrial mammal that evolved in the country. It inhabits native forest, shrubland, and occasionally urban gardens, roosting in tree cavities, caves, and old buildings. The species is distinguished by a relatively long tail that extends beyond the uropatagium, a short, rounded head, and ears with a distinctive notch. Its fur is dark brown on the dorsal side and lighter ventrally. Using high‑frequency echolocation calls (around 45‑55 kHz), it forages at dusk and night, catching insects on the wing. The long‑tailed bat is listed as Endangered on the IUCN Red List due to its small, fragmented population, estimated at fewer than 10,000 mature individuals, and ongoing threats from habitat loss and introduced predators. Conservation efforts focus on protecting roost sites, predator control, and public awareness.

Long‑tailed bats are nocturnal and highly agile fliers, emerging from roosts at twilight to hunt insects over forest canopies and open clearings. They form small colonies of 5‑30 individuals, often sharing roosts with other native bat species. Within colonies, a loose social hierarchy exists, with dominant females occupying the most secure crevices. Males defend small foraging territories that may overlap with several females’ ranges. Communication relies on a repertoire of echolocation pulses for navigation and prey detection, supplemented by low‑frequency social calls used during mating and mother‑pup interactions. Roost fidelity is strong; individuals return to the same tree cavity or cave for many years, but they will relocate if disturbance or predation risk increases.

The New Zealand long‑tailed bat is an insectivore, feeding almost exclusively on aerial insects captured in flight. Its diet is dominated by moths (Lepidoptera), beetles (Coleoptera), flies (Diptera), and occasionally small moth‑like noctuid species. Seasonal shifts occur; during summer, beetles and moths comprise up to 70 % of prey items, while in autumn, flies become more prevalent. Bats hunt using a combination of aerial hawking—pursuing insects on the wing—and gleaning, where they pluck prey from foliage or water surfaces. An adult consumes roughly 3‑5 % of its body weight each night, equivalent to 0.2‑0.5 g of insects, which provides the high metabolic energy required for sustained flight.

Females reach sexual maturity at about one year of age. Breeding occurs once a year, typically in late autumn (April–May), with delayed fertilisation allowing implantation in spring when insect prey becomes abundant. Gestation lasts roughly 40‑45 days, after which a single pup is born in a protected roost. Newborns weigh about 1.5 g and are altricial, relying entirely on maternal milk for the first 4‑5 weeks. Mothers nurse the pup continuously, returning to the roost nightly to forage. By eight weeks, pups are capable of flight and begin independent foraging, though they may remain in the natal colony for several months before dispersing to establish their own territories.

The IUCN classifies the long‑tailed bat as Endangered, with the total population estimated at 5,000‑10,000 mature individuals. Primary threats include habitat loss from deforestation, agricultural conversion, and urban expansion, which reduce available roosting trees and foraging corridors. Introduced mammalian predators—particularly stoats, rats, and feral cats—prey on roosting bats and their pups, causing high mortality rates. Disturbance of roost sites by human activities, such as cave tourism and tree removal, further exacerbates declines. Climate change may alter insect prey availability and increase extreme weather events that damage roost habitats. Conservation actions focus on protecting key forest blocks, installing predator‑proof roost boxes, and conducting monitoring programs to track population trends.

• The long‑tailed bat is the only native terrestrial mammal that evolved in New Zealand.
• It can enter torpor, lowering its body temperature to conserve energy during cold nights.
• Its echolocation calls are among the highest frequency of any New Zealand bat, allowing detection of very small insects.
• Females can store sperm over winter, timing fertilisation to coincide with peak insect abundance.
• Long‑tailed bats have been observed roosting in historic wooden churches, highlighting their adaptability to human structures.