Rhinolophus cognatus, K Andersen, 1906

Burgin, Connor, 2019, Rhinolophidae, Handbook of the Mammals of the World – Volume 9 Bats, Barcelona: Lynx Edicions, pp. 280-332 : 314

72 . Andaman Horseshoe Bat

Rhinolophus cognatus

French: Rhinolophe de Giglioli / German: Andamanen-Hufeisennase / Spanish: Herradura de Andaman

Taxonomy. Rhinolophus cognatus K Andersen, 1906 ,

“ Port Blair, South Andaman Island ,” India.

Rhinolophus cognatus is included in the pusillus species group. The exact relationship of this species to other Rhinolophus species is uncertain. Validity of race famulus is sometimes questioned. Two subspecies recognized.

Subspecies and Distribution.

R. c. cognatus K Andersen, 1906 - Andaman Is (South Andaman).

R. c. famulus K. Andersen, 1918 - Andaman Is (North, Point, Interview, Baratang, and Narcondam).

The species is not known from the Nicobar Is, despite a number of sources listing it from them.

Descriptive notes. Head-body 36- 9 mm (average), tail 13-21 mm, ear 13-5-18- 3 mm, hindfoot 6- 5-9 mm, forearm 37-5-40- 7 mm; weight 9- 9 g (average). There is no published information about its coloration. Ears are medium-sized. Noseleafhas tall lancet with concave lateral margins and spatulate tip; connecting process is hom-shaped and slightly curved downward near tip; sella is relatively large and slightly narrows from base, with widely rounded tip; horseshoe is relatively wide (6-5-7- 1 mm) and lateral leaflets are conspicuous. There are three mental grooves on lower lip. Skull is moderately robust (zygomatic width is greater than mastoid width); anterior and lateral rostral swellings are moderately developed; rostral profile is sloped backward; sagittal crest is moderately developed; frontal depression is shallow; supraorbital ridges are well developed. C1 is relatively slender and long; P2 is medium-sized and within tooth row; P 3 is either within tooth row or half-extruded from it, separating P2 from P 4.

Habitat. Subtropical and tropical moist lowland forest, mangrove forest, and swamps, at elevations up to 600 m.

Food and Feeding. Andaman Horseshoe Bats are insectivorous. An individual was observed hunting from a constant perch at the edge of moist lowland forest, suggesting that the species probably perch-hunts.

Breeding. No information.

Activity patterns. The Andaman Horseshoe Bat roosts mainly in caves and hollows in trees. Some individuals in a large limestone cave on Baratang were seen in torpor in January when the average minimum temperature was 18°C. Search call shape is FM/ CF/FM with a peak F of 85-2-92-1 kHz (mean 89-9 kHz) and duration of 40-2-82-1 milliseconds (mean 53-1 milliseconds).

Movements, Home range and Social organization. Average colony size in caves appears to be less than 50 individuals. The Andaman Horseshoe Bat is known to form mixedspecies colonies, and it frequently shares its cave roosts with Homfray’s Horseshoe Bat (. andamanensis ).

Status and Conservation. Classified as Endangered on The IUCN ed List. The Andaman Horseshoe Bat is poorly known, and its distribution is limited to a few islands within the Andamans. It is threatened by roost disturbance due to the collection of nests of edible-nest swiftlets (Aerodramusfuciphagus), which share the caves with these bats. There are currently no conservation measures in place for this species and it remains unprotected by in the Indian Wildlife (Protection) Act, 1972. However, much of the distribution of this species falls within protected areas. Further studies are needed to understand the ecology of this species and potential threats.

Bibliography. Aul (2003, 2006), Aul & Chakravarty (2016), Aul et al. (2014), Bates & Harrison (1997), Csorba et al. (2003), Srinivasulu & Srinivasulu (2012), Srinivasulu, Racey & Mistry (2010), Srinivasulu, Srinivasulu et al. (2017).

Figures

On following pages: 52. Eastern Horseshoe Bat (Rhinolophus megaphyllus}; 53. Insular Horseshoe Bat (Rhinolophus keyensis}; 54. Yellow-faced Horseshoe Bat (Rhinolophus virgo}; 55. Madura Horseshoe Bat (Rhinolophus madurensis}; 56. Sulawesi Horseshoe Bat (Rhinolophus celebensis}; 57. Robinson's Horseshoe Bat (Rhinolophus robinsoni); 58. Indochinese Horseshoe Bat (Rhinolophus chasem); 59. Anamban Horseshoe Bat (Rhinolophus nereis}; 60. Bornean Horseshoe Bat (Rhinolophus borneensis); 61. Malayan Horseshoe Bat (Rhinolophus malayanus}; 62. Acuminate Horseshoe Bat (Rhinolophus acuminatus}; 63. Acuminate Horseshoe Bat (Rhinolophus acuminatus}; 64. Little Japanese Horseshoe Bat (Rhinolophus cornutus}; 65. Yaeyama Horseshoe Bat (Rhinolophus perditus}; 66. Mountain Horseshoe Bat (Rhinolophus monticolus}; 67. Shortridge's Horseshoe Bat (Rhinolophus shortridgei}; 68. Formosan Horseshoe Bat (Rhinolophus monoceros}; 69. Least Horseshoe Bat (Rhinolophus pusillus}; 70. Little Nepalese Horseshoe Bat (Rhinolophus subbadius}; 71. Convex Horseshoe Bat (Rhinolophus convexus}; 72. Andaman Horseshoe Bat (Rhinolophus cognatus}; 73. Glossy Horseshoe Bat (Rhinolophus refulgens}; 74. Blyth's Horseshoe Bat (Rhinolophus lepidus};

Subspecies and Distribution. R. c. cognatus K Andersen, 1906 - Andaman Is (South Andaman). R. c. famulus K. Andersen, 1918 - Andaman Is (North, Point, Interview, Baratang, and Narcondam). The species is not known from the Nicobar Is, despite a number of sources listing it from them.