165.

Northern Broad-nosed Bat

Scotorepens sanborni

French: Sérotine de Sanborn / German: Sanborn-Breitnasenfledermaus / Spanish: Scotorepo de Sanborn

Taxonomy. Scoteinus sanborni Troughton, 1937,

East Cape, Milne Bay Province, Papua New Guinea.

Placement of Scotorepens and Scoteanax is currently uncertain. They seem to be closely related, but their relationship to other genera of Vespertilionidae is uncertain. They are tentatively included in Eptesicini here, but genetic data are needed to establish their position in the family. They might be related to other Australasian vespertilionids such as Falsistrellus, Vespadelus, Chalinolobus, and Nyctophilus . Scotorepens is in need of revision according to unpublished morphological data, and there is a well-known undescribed species of Scotorepens known as the “Central-eastern Broad-nosed Bat” (from south-eastern Queensland and north-eastern New South Wales) that is sympatric with the three other species of Scotorepens: S. greyii, S. balstoni, and S. orion . Monotypic.

Distribution. Timor I, SE New Guinea (as well as Dolak I), and NE Western Australia, NW Northern Territory, and NE Queensland, Australia.

Descriptive notes. Head-body 36-8-57 mm, tail 27-5-38-9 mm, ear 9-1-13-5 mm, hindfoot 7-1-9 mm, forearm 27-9-37 mm; weight 5-7-9-1 g. The Northern Broadnosed Bat is almost identical to the Little Broad-nosed Bat ( S. greyii), which can only be identified by genetics, skull measurements, and plotting braincase width against palatal length. Forearm length increases from west to east and from south to north. Dorsal pelage of the Northern Broad-nosed Bat is tawny brown (hairs brown with light reddish tinge and dark bases); ventral pelage is slightly lighter. Ears are relatively slender and subtriangular, anterior edge being smoothly convex with rounded tip; tragus is evenly curved upward, with concave anterior edge, moderately convex posterior edge, and rounded tip. Muzzle is broad, with square-shape and inflated glands on each side, and nostrils are simple and rounded, diverging from one another. Bare parts offace, ears, and membranes are dark brown. Wing attaches at base offifth toe, and uropatagium extends from long calcar to tail tip; calcar stretches about halfway to tail and has small calcaneal lobe. Glans penis has up to ten spines on head, mainly in two long rows. Baculum is short (2-4-2-6 mm), with relatively robust shaft thatis slightly curved in lateral view; distal head is bifurcated, with two short narrow prongs behind which shaft occasionally narrows slightly before enlarging into slight lateral flanges; base is moderately wide, gently curved posterodorsally, and occasionally more squared in line of shaft; there is a groove on caudal and cranial surface of base that is shallow and wide and meets as a notch at apex. Skull is short, with relatively wide cranium; sagittal and lambdoidal crests are absent; anterior palatal notch is semicircular, usually ending in line with anterior (occasionally posterior) edge of P* I? is unicuspid and does not touch C'; P* is one-half to two-thirds the height of C' and touchesit; lower incisors are tricuspid; and P, is small and less than one-half the height of P,. Dental formula for all species of Scotorepensis11/3,C1/1,P1/2,M 3/3 (x2) = 30.

Habitat. Various habitats including monsoon forests, open woodlands, and heathlands and apparent preference for mangrove and floodplain areas adjacent to paperbark forests (Kimberley region of north-western Australia) from sea level up to ¢. 2200 m.

Food and Feeding. The Northern Broad-nosed Bat forages close to cluttered vegetation by aerial-hawking and has been observed foraging 4-5 m aboveground in the forest understory of Queensland. In the Top End region, fecal and stomach samples mainly contained beetles (44-2% by volume), true bugs (27-7%), and hymenopterans (17-7%), along with smaller amounts of lepidopterans, cockroaches, termites, neuropterans, and flies (although individuals were not differentiated from the Little Broad-nosed Bat).

Breeding. Pregnant Northern Broad-nosed Bats have been caught in August-September. One or two young (generally one) are born in late September or early December.

Activity patterns. The Northern Broad-nosed Bat roosts in hollow trees and buildings. It forages along rivers and edges of quiet bays, along paths and roads, and around lights in urban areas. Call shape is steep FM/QCF sweep. In Kimberley, characteristic frequency averaged 41-1 kHz, with durations of 6-12 milliseconds. Another study in the Top End region found characteristic frequencies of 34-6—41-4 kHz (mean 38 kHz), but these were not differentiable from the Little Broad-nosed Bat.

Movements, Home range and Social organization. Northern Broad-nosed Bats roost in colonies of a few individuals (often ¢.20 individuals) in tree hollows up to several hundred individuals in buildings.

Status and Conservation. Classified as Least Concern on The IUCN Red Lust.

Bibliography. Baverstock et al. (1987), Bonaccorso (1998), Churchill (2008), Flannery (1995a, 1995b), Hall (2008d), Hutson, Schlitter, Csorba, Bonaccorso & McKenzie (2008), Kitchener & Caputi (1985), Kitchener, Adams & Boeadi (1994), McKenzie & Bullen (2012), McKenzie & Rolfe (1986), Milne (2002), Milne, Armstrong et al. (2004), Milne, Burwell & Pavey (2016).