Rhinopoma cystops (Thoması 1903)

Benda, P., Kasso, M., Nicolas, V., Pleurdeau, D., Stoetzel, E., Workalemahu, S., Bekele, A. & Denys, C., 2019, New data on bats from Dire Dawa regionı eastern Ethiopiaı with the first record of Rhinopoma microphyllum in the country, Journal of Natural History 53 (41), pp. 2579-2590 : 2585-2586

Rhinopoma cystops (Thoması 1903) – lesser mouse-tailed bat

Material. 1 ♀ sad (DDW23), Goda Buticha Cave , 9 km S of Hurso (23 km WSW of Dire Dawa), 09°33 ʹ N, 41°38 ʹ E, 1382 m a. s. l., 23/11/2017.

A subadult female of the lesser mouse-tailed bat was caught inside the Goda Buticha Cave in the same place as R. microphyllum . External measurements of the collected specimen are as follows: weight 10 g, head and body length 67 mm, tail length 69 mm, forearm length 56 mm, ear length 17 mm, tragus length 6 mm; the skull is not available for examination. According to the body size (forearm length) and the relative long tail (longer than forearm), this specimen represents the lesser mouse-tailed bat, R. cystops (sensu Hulva et al. 2007). This species identification was confirmed also by molecular genetic analysis ( Figure 2 ).

Although R. cystops belongs to widespread bat species in the arid zone of the northern part of Africa ( Van Cakenberghe and De Vree 1994; Aulagnier 2013a), in Ethiopia this bat was documented only from few sites in a limited region of the upper part of the Awash valley at Metahara ( Hill and Morris 1971; Largen et al. 1974; Demeter 1982; Benda et al. 2017). The new record from the Dire Dawa area significantly enlarges the known range of this bat species in Ethiopia and eastern Africa generally. It falls close close to the delimitation line of the south-eastern limits of the African species range, continuing eastward to northern Somalia ( Van Cakenberghe and De Vree 1994; Lanza et al. 2015). The new east-Ethiopian record represents also the highest African altitude recorded, since the other Ethiopian findings come from sites situated around 1000 m a. s. l. ( Hill and Morris 1971; Largen et al. 1974) and the altitude maximum known from the Algerian Sahara approaches 1200 m a. s. l. only (cf. Kowalski and Rzebik-Kowalska 1991).

The size of the Dire Dawa specimen of R. cystops conforms to the size of the known Ethiopian bats, in which the forearm length (FA) was reported in the range of 52.9 – 56.6 mm (mean 55.0 mm, n = 13; Hill and Morris 1971) and 54.5 – 57.8 mm (mean 56.4 mm, n = 3; Benda et al. 2017), respectively. The Ethiopian samples are in size very similar to the southern Arabian samples of R. cystops (FA 50.5 – 58.9 mm, mean 54.9 mm, n = 52; Benda et al. 2017), but significantly differ from the large-sized bats from Somalia (FA 59.7 – 67.0 mm, mean 62.9 mm, n = 12; Benda et al. 2017). The results of the molecular genetic comparison ( Figure 2 ) clustered the Dire Dawa specimen with the sequences of R. cystops from the Middle East ( Yemen, Socotra, Jordan, Syria), creating a sister lineage to the sequences from North Africa ( Egypt, Libya). The genetic similarities thus are in accordance with the morphometric findings (see also Benda et al. 2017).

Hulva et al. (2007) referred the two lineages of R. cystops to two subspecies, African R. c. cystops and Middle Eastern R. c. arabium Thomas, 1913 and the Red Sea was regarded as a border between these lineages/subspecies. However, while the Ethiopian sample belongs to the Middle Eastern lineage by our analysis, perhaps all species ’ populations of the Horn of Africa belong rather to R. c. arabium than to the nominotypical form. An alternative explanation of this result could be a mosaic-like border between the lineages, when a certain percentage of individuals of one of the bordering population bears haplotypes of the opposite populations, similarly, as it was already found in Rousettus aegyptiacus and/or Asellia tridens (Geoffroy, 1813) in the identical geographical arrangement across the Red Sea (see Benda et al. 2012b; Bray and Benda 2016).

Figures

Figure 2. Bayesian consensus tree showing position of the two Rhinopoma samples from Dire Dawa area, Ethiopia (DDW22 and DDW23) based on the cytochrome b sequences. Numbers at nodes indicated posterior probabilities (only the values higher than 0.90 are presented).