Otomops harrisoni, Ralph, Richards, Taylor, Napier & Lamb, 2015

Don E. Wilson & Russell A. Mittermeier, 2019, Molossidae, Handbook of the Mammals of the World – Volume 9 Bats, Barcelona: Lynx Edicions, pp. 598-672 : 657-658

94.

Harrison's Giant Mastff Bat

Otomops harrisoni

French: Tadaride de Harrison / German: Harrison-Riesenbulldogfledermaus / Spanish: Otomops de Harrison

Other common names: Harrison's Large-eared Giant Mastiff Bat

Taxonomy. Otomops harrisoni Ralph et al., 2015 ,

“ Ethiopia, Bale District, S of Omar Cave 06°54’N; 40°48’E; elevation 1340 m.”

Otomops harrisoni was until recently included in O. martiensseni but the two species can be distinguished on molecular, ecological, biogeographic and morphometric grounds. A recent molecular study by B. D. Patterson and colleagues, in 2018, showed that the two species maintain their genetic distinctness where they co-occur ( Uganda, Kenya, and Rwanda), reinforcing the conclusion that they are valid species. Monotypic.

Distribution. Occurs patchily in NE & E Africa ( Eritrea, Djibouti, Ethiopia, Uganda, Rwanda, and Kenya) and SW Arabian Peninsula ( Yemen).

Descriptive notes. Head-body 90-109 mm, tail 40-58 mm, ear 34-46 mm, hindfoot 11-16 mm, forearm 64-74 mm; weight 27-45 g. Males average slightly larger than females in external and cranial measurements. Fur is similar to that of the Largeeared Giant Mastiff Bat ( O. martiensseni ), soft, dense, and dark brown with dark rustybrown tinge, or blackish brown, darker on head and body, with pale brown or white band across shoulders, and a thin band of pale brown separating dark dorsal pelage from dark wing membrane on each side; belly is dark brown and throat paler. Face is pink with pig-like snout. Upper lip is expansible with many fine wrinkles and no spoon-hairs. Ears are rounded,fairly stiff, projecting forward well beyond snout; inner margins are joined together and to muzzle. Tragus is minute; antitragusis absent but a semicircular flap extends forward from base of ear and can be folded down to seal ear opening. There is no interaural crest. Gular sac is present in both sexes, well developed in adults. Wings and interfemoral membrane are blackish brown. Anterior of braincase is moderately elevated above plane of rostrum; zygomatic arches have prominent vertical projection; sagittal crest is moderate; lambdoid crest is low or absent; there is no helmet; anterior palatal emargination is very narrow and deep; basisphenoid pits are very deep and wide. Dentition is weak; P* is small but rising well above cingulum of P* M® with third ridge equal to, or slightly shorter than, second; lower incisors are bicuspid; C, has cingula weakly developed and well separated. Dental formula for all members of Otomopsis11/2,C1/1,P 2/2, M 3/3 (x2) = 30. Chromosomal complement in Kenya —which could be either present species or the Large-eared Giant Mastiff Bat—has 2n = 48 and FNa = 56 or 58.

Habitat. High-elevation areas (above 1000 m) associated with a diverse range of tropical to semiarid habitats (less than 500 mm annual rainfall), including woodlands, shrublands, montane grasslands, forests, dry grasslands, bushlands, and thickets.

Food and Feeding. In Ethiopia, based on microscopic analysis of fecal pellets, 97% of the diet by volume comprised medium to large Lepidoptera of three families ( Noctuidae , Geometridae , and Saturniidae ).

Breeding. No information.

Activity patterns. Harrison’s Giant Mastiff Bats typically roost in mountain-associated cave systems, including lava caves (e.g. Mount Suswa and Ithundu in the Rift Valley and Chyulu Hills in Kenya) and karst systems (e.g. Sof Omar cave system of Ethiopia). One roost was located in a disused railway tunnel near Asmara, Eritrea. At Bungule, southeastern Kenya, an individual was recorded emitting echolocation calls of low frequency (minimum c.10-5 kHz, and peak c.12 kHz) and long duration (9 milliseconds).

Movements, Home range and Social organization. Harrison's Giant Mastiff Bats roost communally in small to large colonies. Seasonal absences from some roosts suggest that they may migrate.

Status and Conservation. Classified as Vulnerable on The IUCN Red List, in view of major declines noted at important roostsites in caves of Mount Suswa and Ithundu. Threats include disturbance of caves due to guano mining and tourist-related activities, as well as the blocking of some cave entrances; excessive scientific collecting may also have played a part in these declines.

Bibliography. ACR (2017), Long (1995), Mutere (1973b), Patterson et al. (2018), Ralph et al. (2015), Richards (2017).

Figures

14. Bonda Mastiff Bat (Molossus currentium), 15. Fenton’s Masuft Bat (Molossus fentoni), 17. Pallas’s Mastiff Bat (Molossus molossus), 18. Miller’s Mastiff Bat (Molossus pretiosus), 19. Black Mastiff Bat (Molossus rufus)

Distribution. Occurs patchily in NE & E Africa ( Eritrea , Djibouti , Ethiopia , Uganda , Rwanda , and Kenya ) and SW Arabian Peninsula ( Yemen ).