162.

Great Evening Bat

Ia io

French: Sérotine vespérale / German: Grofl 3e Abendfledermaus / Spanish: Vespertino mayor

Taxonomy. Ia io Thomas, 1902,

“Chung Yang [= Chung-yang], S. Hupeh, China.”

Ia is sister to Scotomanes within Eptesicini based on phylogenetic data. It has been considered a subgenus of Pipistrellus, but the two genera are not closely related. Two subspecies recognized.

Subspecies and Distribution.

I.i.ioThomas,1902—CNepal,NEIndia(AssamandMeghalaya),N&EMyanmar,China(Sichuan,Yunnan,Guizhou,Guangxi,Shaanxi,Hubei,Hunan,Jiangsu,Anhui,andJiangxi),NWThailand,N&CLaos,andN&CVietnam.

I. i. peninsulata Soisook et al., 2017 — peninsular Thailand (Surat Thani and Phang Nga provinces).

Descriptive notes. Head-body 83-107-1 mm,tail 45-4-83 mm, ear 19-9-28.7 mm, hindfoot 13-18 mm, forearm 66-83-1 mm; weight 48-54 g. The Great Evening Bat is very large and is challenged only by the African Schreber’s Yellow Bat ( Scotophilus nigrita) as the largest vespertilionid. Subspecies peninsulata averages larger in external and skull measurements than nominate io. Dorsal pelage is dark smoky brown to dark brown; venter is dark grayish brown; subspecies peninsulata has whitish brown ring stretching across chest that is absent in nominate io. Ventral pelage extends onto a good part of wing membranes, and hair on flanks, ventral wing membrane, and genital region is orangish brown. Ears are relatively large, with rounded tips and hair densely covering dorsal surface and lightly covering part under anterior border, which is rounded with thickened anterior rim; posterior border of ear is somewhat wrinkled; and tragusis broad and slightly projected anteriorly, with bluntly rounded tip. Face and muzzle are naked and deep rosy smoky brown; muzzle has inflated glands on eitherside, with outward turned nostrils. Membranes are dark brown. Uropatagium extends from calcar at ankle to tip of long tail; calcar lacks lobe or has very weakly developed lobe. Baculum is ¢.1-8 mm and somewhat triangular without any bifurcation in nominate io and c.1-2 mm long and somewhat X-shaped with narrower tip than base, deep bifurcation at tip, and another more pronounced bifurcation at base in subspecies peninsulata. Skull is robust; sagittal crest is well developed; occiputis noticeably protruding up and back; palate is narrow; basisphenoid is longer than wide; I? is unicuspid but relatively large (one-third the height to C'); P* contacts C!; P? is minute and displaced inward; P, is rounded; and P, is erther rectangular (i0) or squarish (peninsulata) in outline. Dental formula is 12/3, C1/1, P2/2,M 3/3 (x2) = 34. Chromosomal complement has 2n = 50 and FN = 48 in China.

Habitat. Tropical moist forests including pristine mixed and deciduous forests in Thailand, wet evergreen forests and limestone karst regions in Vietnam, and pine forests in China at elevations of 200-1700 m.

Food and Feeding. The Great Evening Bat is a generalist insectivore/carnivore, feeding on small birds and arthropods. In Guizhou, China, feces from November, July, and September contained 82% birds (by volume), 85% Coleoptera in May, 44-6% birds and 48-7% Coleoptera in July, and 41-1% birds and 43-4% Coleoptera in September. Lepidoptera, Hemiptera, Orthoptera, and Hymenoptera were also found in feces. In Meghalaya, India, diets mainly include Coleoptera and birds but varied throughout the year, with Coleoptera being most prevalent in December, January, and April when birds were completely absent. Birds were most prevalent in March and were found in fewer samples in November and May. Other prey reported in the Indian samples included Lepidoptera (substantial in November and March) and traces of Diptera, Orthoptera, and Hemiptera . Stomach samples from peninsular Thailand included 90% Coleoptera, with no birds.

Breeding. In Sichuan, China, 83% of female Great Evening Bats collected in late April were pregnant, each with one embryo.

Activity patterns. Great Evening Bats are nocturnal and roost exclusively in caves. Call shape is steep FM sweep, with multiple harmonics. In peninsular Thailand (peninsulata), start frequencies 76-5-92-3 kHz, end frequencies 11-8-14-2 kHz, and peak frequencies 23-6-27-4 kHz. In Myanmar (io), start frequencies 80-9-82-9 kHz, end frequencies 14-9-16-3 kHz, and peak frequencies 26-33-9 kHz.

Movements, Home range and Social organization. Great Evening Bats generally roost in small groups. In China, 55 individuals were captured from a single cave, and a cave with c.100 individuals is known from Nepal. In peninsular Thailand, a roost was recorded with four individuals that shared their cave with Greater Asian False-vampires (Lyroderma lyra) in inner parts of the cave and Pendlebury’s Leaf-nosed Bats (Hipposideros pendleburyi) and Black-bearded Tomb Bats (Zaphozous melanopogon) in the first chamber of the cave. Ten Great Evening Bats in peninsular Thailand and 20 individuals in northern Thailand roosted in caves.

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

Bibliography. Bates & Harrison (1997), Bates et al. (2005), Csorba (1998), Csorba, Bumrungsri, Bates et al. (2008), Feng Jiang, Li Zhenxin, Chen Min et al. (2002), Feng Jiang, Li Zhenxin, Zhou Jiang et al. (2001), Francis (2008a), Gu Xiaoming et al. (2003), Han Baoyin & He Hongzao (2012a, 2012b), Han Baoyin et al. (2007), Kruskop (2013a), Niu Hongxing, Yu Yan & Wang Yanmei (2007), Pen Hungshou et al. (1962), Smith & Xie Yan (2008), Soisook, Sribuarod et al. (2017), Thabah et al. (2007), Topal (1970a), Wu Yi, Harada & Li Yanhong (2004).