Sunday, June 29, 2014

[Mammalogy • 2014] Macroscelides micus • A New Species of Round-eared Sengi (genus Macroscelides) from northwestern Namibia

Etendeka Round-eared Sengi [elephant-shrew]
Macroscelides micus Dumbacher & Rathbun, 2014

FIG. 3.—Captive A) Macroscelides micus (CAS MAM 29699; JPD photo) and B) M. flavicaudatus (CAS MAM 29696; JPD photo), illustrating the diagnostic features of the former: ears that appear pink due to the absence of dark skin pigment; swollen base of tail due to the large subcaudal gland; and rusty pelage of face, dorsum, and tail.
 Typical habitat of M. micus (650 m elevation) on the lower slope of an outcrop at the southern edge of the Awahab Outliers, about 28 km south of the Huab River in northwestern Namibia. The Sherman trap, just beyond the welwitschia plant in the foreground, is where M. micus was captured, and a M. flavicaudatus was captured about 150 m lower on the slope, beyond the trap bag.
doi: 10.1644/13-MAMM-A-159

While studying the systematics and taxonomy of round-eared sengis (genus Macroscelides), we identified an unusual specimen from remote northwestern Namibia in the collection of the California Academy of Sciences. To determine if this represented a different species, we made 9 collecting trips with 5,616 trap-nights of effort that produced 16 voucher specimens (including the original specimen) of the unusual sengi. These specimens are distinguished from other Macroscelides species by morphological metrics (they are smaller), external features (rusty-tinged pelage, large subcaudal gland, and lack of dark skin pigment), and by divergence at 3 independently segregating DNA loci. These traits are the basis for the description of a new species of Macroscelidesthat seems to be confined to gravel plains associated with the distinctive reddish colored Etendeka geological formation of northwestern Namibia. The new species appears to be reproductively isolated from congeners, because portions of its distribution are sympatric with that of the Namib round-eared sengi (M. flavicaudatus), and we found no evidence of hybrid individuals or gene flow. The new species is allopatric with the Karoo round-eared sengi (M. proboscideus), which is found about 500 km to the south. The new species, along with M. flavicaudatus, is endemic to Namibia. With this 3rd species in the genus, there are now 19 recognized extant species in the order Macroscelidea.

Key words: elephant-shrew, Etendeka, Macroscelides, Namibia, new species, phylogenetics, sengi

Etymology.— The derivation of micus is Greek (mickros) meaning small, which reflects the diminutive size of this species; indeed, it is the smallest of any known sengi. This epithet continues the practice of using names that reflect distinctive features of each taxon in this genus (see below). We suggest the common name for the new species be Etendeka round-eared sengi (or elephant-shrew), which is based on the widely recognized common name used when the genus was monospecific (round-eared sengi), and incorporates the name of the region in Namibia where it occurs. Etendeka is from the Himba/Otji-Herero language of the Himba people from northwestern Namibia, and refers to the distinctive flat-topped mountains and rust-colored substrates of the region. The other 2 species in the genus are the Karoo round-eared sengi (M. proboscideus) and the Namib round-eared sengi (M. flavicaudatus)

 Dumbacher, J. P.; Rathbun, G. B.; Osborne, T. O.; Griffin, M.; Eiseb, S. J. 2014. A New Species of Round-eared Sengi (genus Macroscelides) from Namibia. Journal of Mammalogy. 95 (3): 443–454. doi: 10.1644/13-MAMM-A-159

Galen B. Rathbun and John P. Dumbacher. 2015. Home Range and Use of Diurnal Shelters by the Etendeka Round-eared Sengi, A Newly discovered Namibian Endemic Desert Mammal. PeerJ. 3:e1302. DOI: 10.7717/peerj.1302