Scotophilus altilis, Allen, 1914

Vallo, Peter, Reeder, Deeann M., Vodzak, Megan E. & Benda, Petr, 2019, Resurrection of an East African house bat species Scotophilus altilis Allen, 1914 (Chiroptera: Vespertilionidae), Zootaxa 4577 (1), pp. 148-160 : 157-158

Scotophilus altilis

has likely been neglected over time due to its vague taxonomic delimitation and repeated synonymizations with other, largely acknowledged species, with only two specimens identified as S. altilis except the type series ( Allen et al. 1917). A quarter of a century after the description of S. altilis, Allen (1939) himself synonymized this name with murinoflavus von Heuglin, 1861 , another rather obscure taxon described from what is today Eritrea. Since this synonymization, the name S. altilis virtually disappeared from contemporary bat science. Several decades later Kock (1969) extracted S. altilis from S. murinoflavus , and placed it within the content of the currently acknowledged species S. leucogaster , as earlier suggested by Aellen (1952). This taxonomic opinion was later shared also by Koopman (1965, 1975, 1994). An alternative synonymization was suggested by Robbins et al. (1985), who tentatively included S. altilis into S. viridis , whose northern populations are currently recognized as S. nigritellus ( Trujillo et al. 2009) . Most recently, Helgen & McFadden (2001), Simmons (2005) and Van Cakenberghe & Happold (2013) returned to the opinion of Aellen (1952), Kock (1969) and Koopman (1965, 1975, 1994) and listed S. altilis again under the synonymy of the name S. leucogaster .

The herein presented molecular and morphological evidence clearly confirms the separate position of the newly captured specimens from Ethiopia, South Sudan and Kenya to other contemporary acknowledged Scotophilus species. Additional studies are required regarding another possible names for this distinct species, given the earlier synonymization with S. murinoflavus . This later taxon was recently mentioned as one of possible names existing for the yellow-bellied forms pertaining to the morphospecies S. dinganii in Ethiopia and Kenya by Vallo et al. (2011), for which S. colias Thomas, 1904 , or later S. andrewreborii Brooks and Bickham, 2014 , and S. ejetai Brooks and Bickham, 2014 , were proposed. Based on its size and external appearance it seems that the earlier synonymization of S. altilis with S. murinoflavus by Allen (1939) was not justified. Later, Vallo et al. (2013) discussed the possible link of S. altilis to a newly discovered and yet undescribed small-sized Scotophilus species from West Africa ( S. aff. nigritellus ). However, these two morphologically delimited allopatric forms clearly represent independent evolutionary units as shown in the molecular genetic analysis. For the above mentioned reasons, we suggest the resurrection of the long neglected taxon name S. altilis for the respective populations of East African Scotophilus cf. leucogaster .

According to the available evidence, the newly resurrected S. altilis represents a small-sized representative of the genus, occurring in ca. 1400 km long belt of rather low elevation areas of the Nile basin ( Fig. 2 ). This belt could be demarcated by the Blue Nile regions in southeastern Sudan and northwestern Ethiopia in the north, the area of most abundant records from five localities in an area of ca. 150× 100 km, and the eastern banks of Lake Victoria in southwestern Kenya. Its southern distribution may extend westwards to northeastern DR Congo, as assumed from earlier comparison of the Faradje specimens to the paratype specimen from Bados by Allen et al. (1917). In this range, S. altilis occurs in broad sympatry with S. leucogaster (e.g. Kruskop et al. 2016), from which the former could be distinguished by slightly smaller size, but mainly by the conspicuous greyish-brown coloration of the belly ( Fig. 1 ). It also occurs in sympatry or close parapatry with S. colias (sensu Vallo et al. 2011; unpubl. records), which, however, markedly differs by its bright pelage coloration, the yellow belly and reddish-brown back .

Figures

FIGURE 1. (A) External appearance of Scotophilus cf. leucogaster from SW Ethiopia; (B) dorsal view of skull and jaw, and (C) dorsal and (D) ventral view of the skin of the paratype specimen of S. altilis (FMNH 34161) from Bados, Kordofan, Sudan; (E) dorsal and (F) ventral view of Scotophilus cf. leucogaster (USNM 587028) from Kajo Keji, South Sudan. Photograph by A: P. Kaňuch, B–F: D.A.Reeder.

FIGURE 2. Distribution of localities of origin of the newly sampled and/or analyzed Scotophilus cf. leucogaster and known specimens of S. altilis based on Allen (1914) and Allen et al. (1917). The paratype specimen of S. altilis from Bados was included in the molecular and morphometric comparisons.