Rhinopoma cystops, Thomas, 1903

Don E. Wilson & Russell A. Mittermeier, 2019, Rhinopomatidae, Handbook of the Mammals of the World – Volume 9 Bats, Barcelona: Lynx Edicions, pp. 164-176 : 176

5.

Arabian Mouse-tailed Bat

Rhinopoma cystops

French: Rhinopome d'Egypte / German: Arabische Mausschwanzfledermaus / Spanish: Rhinopoma de Egipto

Other common names: Afro-Arabian Mouse-tailed Bat, Egyptian Mouse-tailed Bat

Taxonomy. Rhinopoma cystops Thomas, 1903 ,

“ Luxor, Lower Egypt.”

The epithet cystops was long restricted to a subspecies of R. hardwickii , distributed along Nile Valley in Egypt; in 2007, molecular analyses demonstrated genetic homogeneity of all small-sized forms of Rhinopoma from North Africa to Middle East and deep differences between that clade and the allopatric eastern clade of R. hardwickii sensu stricto (¢.9% in cytochromeb). Shallow genetic differences (c.3% in cytochrome-b) within that clade suggest a distinct position of the population from Middle East (including Socotra Island) for which the name arabium was proposed. P. Benda and P. Vallo in 2017 revealed large genetic distance of the population from south-western part of the distribution ( Senegal, Mauritania, and southern West Sahara) from other forms of the hardwickii — cystops group (6-9% in cytochrome-b), suggesting its distinct speciesstatus. The colony found in Al Joghbub in the eastern Libyan margin of Siwa Oasis depression has considerable phenotypic differences from the Egyptian population suggesting its long-term isolation. Two subspecies recognized.

Subspecies and Distribution.

R.c.cystopsThomas,1903—NAfricafromMoroccotoNileValleyinEgypt,Sudan,andNSouthSudan,alsoinSahelregioninEMali,BurkinaFaso,Niger,andNChad.

R. c. arabium Thomas, 1913 — extreme SW Syria, Levant, W Arabia S to Yemen and SE to W Oman (including Socotra I) and Horn of Africa (S Eritrea, Ethiopia, Djibouti, and N Somalia).

Also, in S Western Sahara, Mauritania, and Senegal but probably a separate not yet described species there.

Descriptive notes. Head-body 52-72 mm, tail 54-82 mm, ear 16-23-7 mm, forearm 50-67 mm; weight 6-5-17 g. The Arabian Mouse-tailed Bat is medium-sized (greatest lengths of skull 15-19-9 mm and lengths of tooth row from C' to M? 5-4-6-7 mm) and most similar to the Lesser Mouse-tailed Bat ( R. hardwickii ). Tail is very long (54— 78 mm), slender, and longer that forearm. Although particular populations throughout North Africa and the Middle East have only indistinct differences in cytochrome-b, considerable phenotypic shifts could take place in some isolated local populations from that region. In particular, it was reported that individuals from Libya and Somalia differed significantly in large body size (forearm lengths 58-67 mm and greatest lengths of skull 17-6-19-9 mm) and almost whitish color from those in the Nile Valley or Maghreb (forearm lengths 50-62 mm and greatest lengths of skull 15-7-18-5 mm). Narial pad of muzzle has inflated lateral ridges, broad internarial ridge, and wellpronounced dorsal ridge tapered in small triangular noseleaf. Hairs of the Arabian Mouse-tailed Bat are unicolored; pelage is silky, dark sepia gray on back and paler gray to whitish on ventral side. Wings and membranes are medium to dark brown. Locally (e.g. in Libya), color can be much paler, almost whitish, including membranes and skin. Rump and lower abdomen are naked or only sparsely haired. Tibia is long, uropatagium is somewhat broader that in the Muscat Mouse-tailed Bat ( R. muscatellum ) and the Greater Mouse-tailed Bat ( R. microphyllum ), fifth tail vertebra is included completely in the membrane which attaches to tibia at distal one-fifth of its length. Skull has elongated braincase and distinct sagittal crest in frontal region. Rostrum is broad, with moderately enlarged nasal swellings anteriorly extending to a level of distal margin of canines. Dorsal surface of nasal region is flat or with broad shallow groove, mostly triangular in outline without extending into sharp converging crests. Preorbital foramen is indistinct and dot-like. Palatal incision is broad, U-shaped, and extended to level of distal margins of M®. Dentition is robust, with all tooth row elements generally in direct contact. Talons of P*, M', and M? are quite large, with high palatal walls uplifting mesially into distinct cusps and separated from palatal walls of protocones in molars. Post-protocrista is often retained in M? and M'. M? is reduced, and rudiment of metacrista passes parallel to distal margin oftooth. C, lacks cingularridge, P, is small and oriented in axis of tooth row, and P, is broadly rectangular to square on section without distinct tapering ofits mesial margin. K. Wassif and G. Madkour provided additional morphological details in a series of descriptive studies in Egypt. Chromosomal data (including Gand C-banding) are available for populations in the Middle East and Egypt; chromosomal complement of the Arabian Mouse-tailed Bat has 2n = 36 and FN = 68, the same as Lesser Mouse-tailed Bat in India.

Habitat. Arid and semi-desert vegetation zones, including semi-desert grassland with areas of Acacia (Fabaceae) scrub, oases with gardens, orchards surrounded by sandy desert and hamada (large barren, rocky plateaus), and gorges of wadis with some Tamanix ( Tamaricaceae ) and Nerium oleander ( Apocynaceae ), up to elevations of ¢. 1100 m in the Maghreb and western Arabia. Arabian Mouse-tailed Bats roost in dry caves, ruins, underground tunnels (including catacombs), mosques and old buildings, and sometimesfissures, small crevices, and among boulders.

Food and Feeding. The Arabian Mouse-tailed Bat forages in open space at heights of c. 10 m. Diet analyses are mostly based on occasional sampling in spring and late autumn. Diets in Israel in August-October contained beetles (51%) and ants (30%), supplemented by other groups comprising mostly less than 1% except for Heteroptera, mostly Lygaeidae (6%). Winged ants and beetles (mostly small Scarabaeidae ) and regularly Auchenorhyncha, Heteroptera, and Orthoptera dominated diets in Jordan, Oman, Sudan, and Yemen. A representative sample from Libya in mid-May was clearly dominated by winged ants (81%), supplemented by beetles (mostly Tenebrionidae ).

Breeding. Female Arabian Mouse-tailed Bats give birth to single young each year. Timing of particular stages of reproduction of the Arabian Mouse-tailed Bat is comparable with those of the Greater Mouse-tailed Bat and the Lesser Mouse-tailed Bat from India. Early stages of pregnancy of the Arabian Mouse-tailed Bat are reported from late March to late April in Egypt and Sudan, suggesting mating in March and April; lactation lasts into August.

Activity patterns. More data suggest inactivity in winter period (October—April) in the Mediterranean. In Israel, Arabian Mouse-tailed Bats survive winter in cave roosts often with the Greater Mouse-tailed Bat. They do no leave roosts to forage or drink and live entirely on fat reserves accumulated in August-October. In a winter colony, continuously monitored individuals had stable mean body temperatures of 21-23°C throughout winter, with an average torpid metabolic rate of 0-16 ml O,/g/h and breathing cycle of c.15 minutes. In contrast to deep-torpor hibernators, shallow-torpor hibernation of rhinopomatids is not interrupted by periodic arousals. Bats hibernate with their eyes open, instantly react to stimuli, and swiftly became active after being disturbed. They are able to fly with low body temperatures (c.23°C). Compared with the Greater Mouse-tailed Bat, the Arabian Mouse-tailed Bat was found to be is more tolerant to low temperatures, which was believed to explain its broader distribution in the Mediterranean. As in other species of Rhinopoma , echolocation calls are multiharmonic qCT pulses with maximum energy at second harmonic. Laboratory analyses on Egyptian bats revealed frequency span 18-20 kHz (first harmonic), 36-40 kHz (second harmonic), 56-60 kHz (third harmonic), and 75-80 kHz (fourth harmonic), with increase of frequency bandwidth and repetition rate and shortening duration during approach flight or landing. Field data indicate considerable between-individual variation and possible between-population variation in mean values of particular variables. From field records of search flight, second harmonics had mean end frequency of 32-5 kHz (range 29-5-35-8 kHz), mean peak frequency of 34-3 kHz (32-37 kHz), and mean duration of eight milliseconds (4-5-12 milliseconds) in Jordan; 30-2 kHz (29-30-8 kHz), 33-2 kHz (32-8-34-4 kHz), and 6-3 milliseconds (5-6—6-9 milliseconds) in Sinai; and 33 kHz (32-5-34-1 kHz), 33-6 kHz (32-8-24-4 kHz), and 9-4 milliseconds (8:6-11-1 milliseconds) in southern Morocco. Anecdotal descriptions include loud series of audible calls produced in a colony prior to evening emergence, distress calls, and communication calls when an individualis entering a colony or coming in contact a conspecific. These broadband communication calls are typically accompanied by a specific shivering of extended wings and dorsally erected tail.

Movements, Home range and Social organization. Little is known on spatial dynamic of this species during course ofyear. Data from Israel suggest the pattern is identical to the Greater Mouse-tailed Bat, namely autumn and spring local migrations associated with changing summer and winter roosts and sexual segregation during summer. Yet despite more records in Arabian Mouse-tailed Bats these phenomena can be less apparent than in the former species, as the Arabian Mouse-tailed Bats only exceptionally form large colonies and,as suggested by occasional observation, the spatial dispersal of its colonies is probably much wider than in the Greater Mouse-tailed Bat, patterned by fission—fusion dynamics. Most records report just a few individuals in a daytime roost or smaller colonies of 10-50 individuals; large colonies (up to 200 individuals) are rare, the largest reported (such as 500 individuals from Jordan or large winter colonies in Israel) are mixed colonies with the Greater Mouse-tailed Bat. Samples taken from colonies in May-July conform to sexual segregation in that period, but samples from other periods include individuals of both sexes as a rule.

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

Bibliography. ACR (2012, 2017 2018), Ahmim & Qubaziz (2017), Ahmim & Tahri (2017), Akmali et al. (2011), Aloufi et al. (2016), Aulagnier (2013e), Aulagnier & Destre (1985), Aulagnier et al. (2017), Benda & Vallo (2017), Benda, Abi Said et al. (2016), Benda, Al-Jumaily et al. (2011), Benda, Andreas et al. (2006), Benda, Hanék et al. (2004), Benda, Lugan et al. (2010), Benda, Reiter et al. (2009), Benda, Ruedi & Aulagnier (2004), Benda, Spitzenberger et al. (2014), Brito et al. (2010), Carpenter, J. et al. (2014), Dalhoumi et al. (2016a), Dieuleveut

Figures

1. Greater Mouse-tailed Bat (Rhinopoma microphyllum), 2. Muscat Mouse-tailed Bat (Rhinopoma muscatellum), 3. Hadramaut Mouse-tailed Bat (Rhinopoma hadramauticum), 4. Lesser Mouse-tailed Bat (Rhinopoma hardwicku), 5. Arabian Mouse-tailed Bat (Rhinopoma cystops)

Subspecies and Distribution. R.c.cystopsThomas,1903—NAfricafromMoroccotoNileValleyinEgypt,Sudan,andNSouthSudan,alsoinSahelregioninEMali,BurkinaFaso,Niger,andNChad. R. c. arabium Thomas, 1913 — extreme SW Syria , Levant, W Arabia S to Yemen and SE to W Oman (including Socotra I) and Horn of Africa (S Eritrea , Ethiopia , Djibouti , and N Somalia ). Also, in S Western Sahara , Mauritania , and Senegal but probably a separate not yet described species there.