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| Dipsadoboa montisilva Branch, Conradie & Tolley
in Branch, Bayliss, Bittencourt-Silva, Conradie, Engelbrecht, et al., 2019.
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Abstract
A new species of tree snake Dipsadoboa montisilva Branch, Conradie & Tolley sp. nov. (Serpentes: Colubridae) is described from the ‘sky islands’ of Mount Mabu and Mount Ribáuè in northern Mozambique. Features of scalation, colour, body form and habitat distinguish the new species from other Dipsadoboa. This is supported by a phylogenetic analysis using one mitochondrial marker (cytochrome b) that shows the new Mozambican species is divergent from other sampled Dipsadoboa, including D. flavida and D. aulica, the only congeners known to occur in Mozambique. Morphologically, the new Dipsadoboa forms part of the D. werneri-shrevei complex from east and southeast Africa, but differs in having higher subcaudal counts, a different temporal pattern and only two supralabials entering the orbit. Phylogenetically, it occurs in a clade with D. shrevei and D. werneri. The status of D. shrevei in East Africa is reassessed, particularly in terms of the poorly-known Dipsadoboa shrevei kageleri from northern Tanzania. It is morphologically well defined from D. shrevei shrevei and utilises a different habitat. Although based on limited genetic data, it appears to be well-defined from typical D. shrevei and is accordingly raised to specific status. The only Tanzanian record for typical D. shrevei from Mtene, Rondo Plateau in southeast Tanzania is well isolated from the species’ range to the west (e.g. Zambia, Angola) and the published scalation features, particularly ventral counts, do not fully accord with D. shrevei. The Rondo Plateau population is treated as Dipsadoboa incerta sedis, and because we return D. shrevei to its binomial status, we can no longer consider D. shrevei as occurring in Tanzania. Biogeographically, the Rondo Plateau population may have a stronger affinity to the new Mozambican species. The discovery of isolated populations of the new species in mid-altitude forest remnants on Mt Mabu and Mt Ribáuè emphasizes the high conservation importance of the Mozambique forest ‘sky islands’ from which numerous other endemic new species have been recently discovered. These species are impacted by ongoing habitat destruction through slash and burn clearing for subsistence agriculture.
Keywords: Reptilia, Dipsadoboa, Serpentes, Colubridae
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| Dipsadoboa montisilva sp. nov. Holotype, adult male, PEM R21122,
Mt Mabu Forest Base Camp, Zambezia Province, Mozambique.
whole body in life, showing uniform olive-brown dorsal coloration and showing the weakly-keeled orange ventrals, whose coloration suffuses onto the three adjacent lateral body scale rows. |
Dipsadoboa montisilva Branch, Conradie & Tolley sp. nov.
Montane Forest Tree Snake
Synonymy:
Dipsadoboa sp. (Timberlake et al. 2012; Bayliss et al. 2014)
Dipsadoboa cf. shrevei (Conradie et al. 2016).
Etymology. The name is derived from the Latin words ‘montem’ = mountain and ‘silva’= forest, which is in
reference to the isolated mountain forest habitat in which it is found on Mt Mabu, Zambezia Province, Mozambique.
The name is in the masculine form.
William R. Branch, Julian Bayliss, Gabriela B. Bittencourt-Silva, Werner Conradie, Hanlie M. Engelbrecht, Simon P. Loader, Michele Menegon, Cristóvão Nanvonamuquitxo and Krystal A. Tolley. 2019. A New Species of Tree Snake (Dipsadoboa, Serpentes: Colubridae) from ‘Sky Island’ Forests in northern Mozambique, with Notes on other Members of the Dipsadoboa werneri group. Zootaxa. 4646(3); 541–563. DOI: 10.11646/zootaxa.4646.3.6
Werner Conradie, Gabriela Bittencourt-Silva, Hanlie M. Engelbrecht, Simon P. Loader, Michele Menegon, Cristóvão Nanvonamuquitxo , Michael Scott and Krystal A. Tolley. 2016. Exploration into the hidden world of Mozambique’s sky island forests: new discoveries of reptiles and amphibians. Zoosystematics and Evolution. 92(2): 163-180. DOI: 10.3897/zse.92.9948
