9.

Dormer’s Bat

Scotozous dormeri

French: Pipistrelle de Dormer / German: DormerZwergfledermaus / Spanish: Pipistrela de Dormer

Other common names: Dormer’s Pipistrelle

Taxonomy. Scotozous dormeri Dobson, 1875,

“Bellary Hills [Mysore], Southern India.”

Scotozous dormeri has variously been placed in Pipistrellus or Scotoecus, but it is now generally considered a separate, monotypic genus. Its phylogenetic relationship is still uncertain, although it is included within Pipistrellini. The existence of several karyotypes suggest that several cryptic species may be included within the currently defined species. Monotypic.

Distribution. E Pakistan (Punjab and Sindh), much of India, extreme SW Nepal, and W & C Bangladesh (Rajshahi and Dhaka); it may also occur in Bhutan.

Descriptive notes. Head-body 39-55 mm, tail 27-41 mm, ear 10-18 mm, hindfoot 5-8 mm, forearm 32-7-36-3 mm. Pelage of Dormer’s Bat is glossy grayish brown dorsally (hairs with pale tips) or occasionally yellowish brown, and paler ventrally (hairs with buffy white tips). Area around nose and lips is bare of hair and midto dark brown, along with ears, uropatagium, and wings. Veins on uropatagium are occasionally white. Ears are short and broad, and tragus is well developed with a small triangular lobe near base of outer margin. Tail is long and almost completely enclosed by uropatagium (except extreme tip). Penis is large. Skull is flattened dorsally with a distinct lambdoid crest. There is generally only one pair of upper incisors, but second pair is occasionally present, although it is minute and spiculate. C' has anterior and posterior cingular cusps but lacks a secondary cusp; molars are nyctalodont. Dental formulaisli 1/3. Cl1/1, P 2/2 M 3/3 (x2)'= 32 or (varely) 12/3, C 1/1, P 2/2, M 3/3 (x2) = 34. Chromosomal complement has 2n = 30 (males) or 2n = 31 (females) and FN = 50 (captive individuals of Indian parentage) or 2n = 36 and FN = 50 (wild individuals from India).

Habitat. Generally found in drier climates and around agricultural and urban environments, occurring in subtropical and tropical dry forests, urban settlements, plantations, and agricultural fields. Dormer’s Bats have been recorded from sea level to c. 2000 m throughout their distribution.

Food and Feeding. Dormer’s Bats are insectivorous. Feeding starts late in evening and they will often stay near their roosting sites. In winter,their diet consists largely of beetles, moths, grasshoppers, and crickets, while in summer and during monsoon season, they feed mostly on winged termites, beetles, moths, orthopterans, and hymenopterans. Many of their food sources are major agricultural pests, which makes the species a good means of controlling pest populations.

Breeding. Dormer’s Bats seem to breed all year round or nearly so. In Maharashtra, breeding occurs year-round and females exhibit postpartum estrus in quick succession, which allows them to have multiple young per year. Pregnant females have been collected in July and September in Rajasthan, in September and October in Gujarat, and in April, July, and October in Bihar. In Uttar Pradesh, immature individuals were captured in October.

Activity patterns. Nocturnal. Dormer’s Bat comes outlate in evening and is a slow flier, despite its fast wingbeats. Roosts often occur in holes in large trees, including banyan trees ( Ficus benghalensis, Moraceae). In more urban settings, roosts have been found in cracks, crevices, and holes in old temples as well as in other old and abandoned buildings and tombs.

Movements, Home range and Social organization. Colonies in roosts have been reported with 2-24 individuals, although solitary individuals have occasionally been found.

Status and Conservation. Classified as Least Concern on The IUCN Red List. Dormer’s Bat does not seem to face any significant threats other than overuse of pesticides in agricultural ecosystems, as it often feeds on pest insects in those areas. The species works somewhat as a natural pesticide since it controls pest insect populations in agricultural environments. It may be declining in some parts of its range due to pesticide overuse.

Bibliography. Bates & Harrison (1997), Corbet & Hill (1992), Das (2003), Hill & Harrison (1987), Khajuria (1965), Khan (2001), Mandal et al. (2000), Menu (1987), Molur & Srinivasulu (2008b), Sreepada et al. (1996), Srinivasulu & Srinivasulu (2005, 2012), Srinivasulu, Racey & Mistry (2010), Srinivasulu, Srinivasulu & Sinha (2013), Tate (1942b), Thapa, Subedi et al. (2012), Vanitharani (2006), Volleth et al. (2001).