This species is virtually identical in appearance to the Papuan pipistrelle (P. papuanensis). In both species the dorsum fur is bicolored, with a brown tip overlying the longer black base of the hair. The ventral fur in both species has a black base tipped with cinnamon brown, and The snout, lip, ear, wing, forearm, and hind foot are clove brown, with a lightly furred uropatagium. However, there are several key morphological differences. P. angulatus has a strongly concave forehead. The first upper incisor is bicuspid, and the height of the second upper incisor is less than the posterior cusp of this tooth. The tragus narrows only slightly at the apex and the antitragus is moderately high.
Pipistrellus angulatus occurs on New Guinea and the Bismarck, Admiralty, D'Entrecasteaux, and Louisiade Island groups. Within Papua New Guinea, Pipistrellus angulatus has been collected from sea level to 2400 m from East New Britain, East Sepik, New Ireland, Gulf, Manus, North Solomons, Milne Bay islands, and Madang, Oro, Sandaun, and Western Provinces. This is species also occurs on Superiori Island, Biak-Numfoor Province in Irian Jaya and on Fauro, New Georgia, Nendo, Guadacanal, and Santa Ysabel Islands in the Solomon Islands.
The New Guinea pipistrelle is known to roost in caves, bamboo stands, and buildings. At dusk, New Guinea pipistrelles emerge from their day roost to forage on aerial insects in mature primary and secondary forest. A maternity colony of 200 bats was active in 1981 in a cave in New Ireland in June, clustered in a 500 cm by 66 cm ceiling hole; another New Ireland colony was discovered living between the roof shingles and wall of school building in June, and both females examined carried embryos. Four male specimens were shot while foraging at dusk at the summit of Mount Kaindi, Morobe Province in July 1968, by P.H. Coleman and A. Ziegler. The flight pattern of this species is slow with many erratic turns.
This bat has a large geographical distribution; it is found on many islands from the Solomons to Biak. It was listed as Lower Risk: Least Concern in the 1996 IUCN Red List of Threatened Animals, and its populations are considered to be secure. However, little is known of the New Guinea pipistrelle's habits, and distribution and population surveys are needed.
- Chiroptera Specialist Group 1996. Pipistrellus angulatus. 2006 IUCN Red List of Threatened Species. Archived June 27, 2014, at the Wayback Machine. Downloaded on 9 July 2007.
- Bonnaccorso, Frank J. 1998. Bats of Papua New Guinea. CI Tropical Field Guide Series. USA: Washington, D.C.
- Flannery, T. F. 1995. Mammals of New Guinea. Australian Museum/Reed Books, Chatswood, New South Wales, Australia.
- Smith, J. D. and C.S. Hood. 1981. A new species and subspecies of bat of the Hipposideros bicolor-group from Papua New Guinea, and the systematic status of Hipposideros calacaratus and Hipposideros cupudis (Mammalia: Chiroptera: Hipposideridae). Contributions in Science, Natural History Museum of Los Angeles County, 331:1-19