The Taxonomic Status of Mazama bricenii and the Significance of the Táchira Depression for Mammalian Endemism in the Cordillera de Mérida, Venezuela

Abstract

We studied the taxonomy and biogeography of Mazama bricenii, a brocket deer classified as Vulnerable by the IUCN, drawing on qualitative and quantitative morphology and sequences of the mitochondrial cytochrome-b gene. We used Ecological Niche Modeling (ENM) to evaluate the hypothesis that M. bricenii of the Venezuelan Cordillera de Mérida (CM) might have become isolated from populations of its putative sister species, Mazama rufina, in the Colombian Cordillera Oriental (CO). This hypothesis assumes that warm, dry climatic conditions in the Táchira Depression were unsuitable for the species. Our analyses did not reveal morphological differences between specimens geographically attributable to M. bricenii and M. rufina, and phylogenetic analyses of molecular data recovered M. bricenii nested within the diversity of M. rufina. These results indicate that M. bricenii should be regarded as a junior synonym of M. rufina. ENM analyses revealed the existence of suitable climatic conditions for M. rufina in the Táchira Depression during the last glacial maximum and even at present, suggesting that gene flow between populations in the CO and CM may have occurred until at least the beginning of the current interglacial period and may continue today. Because this pattern might characterize other mammals currently considered endemic to the CM, we examined which of these species match two criteria that we propose herein to estimate if they can be regarded as endemic to the CM with confidence: (1) that morphological or molecular evidence exists indicating that the putative endemic taxon is distinctive from congeneric populations in the CO; and (2) that the putative endemic taxon is restricted to either cloud forest or páramo, or both. Only Aepeomys reigi, Cryptotis meridensis, and Nasuella meridensis matched both criteria; hence, additional research is necessary to assess the true taxonomic status and distribution of the remaining species thought to be CM endemics.

Terrestrial medium and large-sized mammal’s diversity and activity patterns from Tamá National Natural Park and buffer zone, Colombia

“…M. rufina was considered absent from the eastern mountain range and still its northern distribution is not well known (Lizcano and Alvarez 2008), while M. bricenii is presumed to occur in northern Colombia in areas such as Tamá NNP (Lizcano et al 2010). The classification and identification of M. bricenii and M. rufina have been subject to recent debate (e. g., Solari et al 2013;Gutiérrez et al 2015), however, according to available descriptions for both species (Barrio 2010;Gutiérrez et al 2015), and taxon validity (Gutiérrez et al 2015), our records correspond to M. rufina. We therefore obtained multiple records of M. rufina between 350 and 3,450 m, in areas of tropical forest and Páramo (i. e., Páramo del Tamá and Páramo de Santa Isabel) near the border with Venezuela, indicating that the species is mostly nocturnal and solitary, adding some lights on the scarce knowledge of this species ecology (Lizcano and Alvarez 2008;Merino and Rossi 2010).…”

A new polytypic species of yellow-shouldered bats, genus Sturnira (Mammalia: Chiroptera: Phyllostomidae), from the Andean and coastal mountain systems of Venezuela and Colombia

“…1). The physical characteristics and mammalian biogeography of these systems has been considered in detail in recent studies (Molinari 2007;Anderson & Gutiérrez 2009;Anderson et al 2012;QuirogaCarmona & Molinari 2012;Gutiérrez et al 2015). A succinct description of these mountain systems, and the Venezuelan political divisions (within parentheses) from which we examined specimens, are: 1) Cordillera Oriental [de Colombia], on its Venezuelan side (Táchira, SW of the Táchira Depression; Apure); 2) Sierra de Perijá (or Molecular analysis.…”

The systematics of the Cervidae: a total evidence approach

“…Their fossil record is scarce and thus, the validity of some of the species is doubtful (Alcaraz & Zurita, 2004;Menegaz, 2000;Merino & Rossi, 2010). So far, there are only few studies on extinct neotropical cervids and even fewer attempting to reconstruct the phylogeny of fossil and extant neotropical deer (Gutiérrez et al, 2015;Escobedo-Morales et al, 2016;Gutiérrez et al, 2017).…”

“…Gutiérrez et al (2015) tested whether the degree of concavity of the dorsal outline in lateral view and the shape of the lacrimal fossa can distinguish Mazama bricenii and Mazama rufina, but found that these characters are too variable to discriminate species. In the molecular and TE analyses here, Mazama bricenii was placed as the sister taxon to Mazama rufina, while in Gutiérrez et al (2015) and Gutiérrez et al (2017) Mazama bricenii was nested within Mazama rufina and the opposite was the case in Heckeberg et al (2016). Gutiérrez et al (2015Gutiérrez et al ( , 2017) stated based on their results that Mazama bricenii is not a valid taxon, but a junior synonym of Mazama rufina.…”