78.

New Guinea Big-eared Bat

Pharotis imogene

French: Nyctophile imogene / German: Neuguinea-Langohr / Spanish: Pharotis de Nueva Guinea

Other common names: Thomas's Big-eared Bat

Taxonomy. Pharotis imogene Thomas, 1914,

“Kamali, Lower Kemp Welch River, British New Guinea [= Central Province, Papua New Guinea].”

Pharotis imogene was initially included under Nyctophilus timoriensis (species inquirenda = doubtful identity or name under investigation) by O. Thomas in 1897 until Thomas in 1914 proposed the genus Pharotis for wmogene. Phylogenetic relationships of Pharotis to Nyctophilus and within Vespertilionidae remain unclear. Both genera have been placed in their own subfamily Nyctophilinae or in subfamily Vespertilioninae, sometimes in the distinct tribe Nyctophilini or Vespertilionini . Pharotis has not yet been included in any phylogenetic study, but N. gouldi and N. geoffroyi have nested in Vespertilionini as sister to some species of Chalinolobus and Vespadelus . M. Volleth and C. R. Tidemann in 1991 suggested that Nyctophilus belongs in Vespertilionini based on karyotypic data. Despite uncertainty as to which tribe Pharotis (and Nyctophilus) belongsin,it is listed here under Vespertilionini . More research is needed to determine the real relationship of Pharotis and Nyctophilus . Monotypic.

Distribution. Known only from two localities in Central Province, SE Papua New Guinea, including type locality and Oio village, Abau district, ¢. 120 km E of former. Former records are either misidentified Nyctophilus timoriensis or correspond to N. microdon .

Descriptive notes. Head—body 43-50-1 mm, tail 42-44 mm, ear 23-4-25 mm, hindfoot 7-8-9-4 mm, forearm 37-5-39-6 mm; weight 7-7 g (one specimen). Tibia lengths are 13-1-19 mm. Pharotis and Nyctophilus are the only genera of Vespertilionidae that combine large ears that arejoined by membranejust above forehead—except in the Papuan Long-eared Bat (NN. microtis) and the Pygmy Long-eared Bat (NN. walkeri)—and presence of simple small noseleaf. Upperparts and underparts are dark brown. Wing membranes are uniformly brown and naked. Ears are brown, long, and bluntly pointed and have horizontally ribbing on inner surfaces. Tragus is irregularly lobed. Well-developed auricular band unites ears. Muzzle is strongly truncated and sparsely haired. Noseleaf has rounded anterior projecting flap and posterior cup oriented to anterior flap. Calcaris long (14-15 mm) and robust. Pharotis is distinguished from Nyctophilus as follows: convex dorsal margin of noseleaf above nostrils (vs. median concave margin), deep pit immediately posterior to posterior nasal prominence (vs. absent), lobe on inner margin of tragus located midway between each side of tragus (vs. located on outer margin of tragus), and skin between and above nostrils is completely naked (vs. covered with fine hairs). Baculum is similar to that of Nyctophilus (long and rather broad with scarcely expanded, bilobed base, and broad shaft tapering distally to blunt point, to produce shallow bifid tip; shaft is ventrally deeply fluted), but shaft is narrower, tapering to slightly expanded tip. Braincase is large, smooth with no ridges, and rounded without crests. Rostrum is very short, and nasal notch is deep. Interorbital region is very wide, with smoothly rounded edges. Tympanic bullae are medium-sized (c.3-5 mm); palate is shortened; greatest skull length is ¢. 15 mm; and maxillary tooth row is c.4-5 mm. C' is slightly larger than that of the Small-toothed Long-eared Bat (N. microdon); and upper incisors are noticeably procumbent and angled medially. Dental formulais11/3,C1/1,P1/2,M 3/3 (x2) = 30.

Habitat. Uncertain but either savanna woodlands or lowland rainforest patches in savanna woodlands at upper elevation of ¢. 100 m. In Abau district, south-eastern Papua New Guinea, the single recorded female New Guinea Big-eared Bat was trapped in rainforest less than 100 m from boundary between extensive rainforest and large expanse of grassland (once a coconut plantation) and was within 12 km of the coast and extensive open country.

Food and Feeding. Morphology ofears,skull, and teeth strongly suggests that New Guinea Big-eared Bats forage by gleaning,likely on weevils, other beetles, ants, and moths.

Breeding. No information.

Activity patterns. New Guinea Big-eared Bats are nocturnal.

Movements, Home range and Social organization. [Large number of specimens (45, with six females) originally collected suggests that it was probably a maternity colony. As a part of a broader study of impacts of selective rainforest logging on small mammals of the Cloudy Forest Management Area in Abau district, bats were captured with mist nets and harp traps, and their calls were recorded. A New Guinea Big-eared Bat was captured in this area together with Diadem Leaf-nosed Bats (Hipposideros diadema), Lesser Long-tongued Blossom Bats ( Macroglossus minimus), Large Long-fingered Bats ( Miniopterus magnater), Little Long-fingered Bats (M. australis), Maluku Myotis ( Myotis moluccarum), Papuan Long-eared Bats, New Guinea Pipistrelles ( Pipistrellus angulatus), Lesser Papuan Pipistrelles ( P. papuanus), and Watts’s Pipistrelles ( P. wattsi).

Status and Conservation. Classified as Critically Endangered (Possibly Extinct) on The IUCN Red Last. If the New Guinea Big-eared Bat still exists,it is likely to have a very small population and small distribution that is subject to a continued decline in extent of occurrence, area of occupancy, and extent and quality of habitat. It is one of the top ten island endemic bat (IEB) species as identified by the research priority metric (RPM), ranked in order of research priority. New Guinea Big-eared Bats and Bulmer’s Fruit Bats ( Aproteles bulmerae) are listed among the top 100 mammals in the EDGE (Evolutionary Distinct and Globally Endangered) program. The New Guinea Big-eared Bat is threatened by habitat loss around human population centers (e.g. Kamali, Central Province, Papua New Guinea), reduction of area and quality of small rainforest patches in savanna woodlands, encroachmentof fire, and human activities, particularly firewood collection. It was rediscovered in 2012 (a single individual) from coastal district Abau, 120 km east of the only previous known locality at Kamali. C. Hughes and colleagues in 2014 recommend the following steps to addressit conservation status: bat surveys using harp traps in Abau district and adjoining lowland region to determine local distribution and abundance; whether it can be identified from echolocation calls; and radio-tracking during different stages of reproductive cycle to define habitat use, roosting requirements, and movements.

Bibliography. Amador etal. (2018), Boitani et al. (2006), Bonaccorso (1998), Bonaccorso, Hamilton & Parnaby (2008a), Broken-Brow & Hughes (2012), Conenna et al. (2017), Flannery (1995b), Hill & Harrison (1987), Hoofer & Van Den Bussche (2003), Hughes et al. (2014), Isaac et al. (2007), Koopman (1993, 1994), Koopman & Jones (1970), Nowak (1999), Roehrs et al. (2010), Simmons (2005), Tate (1941e, 1942b), Thomas (1897b, 1914c), Volleth & Tidemann (1991).