Natural history and demography of Thalpomys lasiotis (Thomas, 1916), a rare and endemic species from the Brazilian savanna

Abstract

Hairy-eared cerrado mouse Thalpomys lasiotis is an endemic species of the cerrado biome. It can be found in open habitats, but its distribution is patchy and population numbers are unknown. In this paper, we describe, for the first time, aspects related to the ecology and natural history of T. lasiotis, detailing demographic parameters such as population densities, reproduction, home range, and longevity of this endemic and rare species. We captured, marked, and recaptured 55 individuals of T. lasiotis in Águas Emendadas Ecological Station, located in the northeast of the Federal District, Brazil. We found significant differences on population numbers and densities between the dry and wet seasons. Densities and population numbers apparently are affected by the seasonality of food resources. Moreover, the breeding season is seasonal, and both males and females were reproductively active during the wet season. T. lasiotis showed a permanence time ranging from 2-9 months, which means that individuals can survive for at least 9 months in natural habitats. The home ranges of males and females of T. lasiotis were not significantly different. However, males have larger home ranges than females and the mean distance moved by males was higher than the distance moved by females, which is consistent with the hypothesis that males belonging to polygynous species tend to move greater distances to avoid agonistic encounters and to search sexual partners.

The mammalian faunas endemic to the Cerrado and the Caatinga

“…Thalpomys lasiotis is endemic to the Cerrado, and has been recorded in the Brazilian states of Bahia, Minas Gerais, Rondônia, and São Paulo, and in the Distrito Federal (Hershkovitz 1990a, Ribeiro et al 2010, 2011, Rocha et al 2011a, Pardiñas and Teta 2015). …”

Evolutionary affinities of the ‘Lost World’ mouse suggest a late Pliocene connection between the Guiana and Brazilian shields

“…The two species of Thalpomys, T. cerradensis and T. lasiotis, are both restricted to the Cerrado vegetation in the Brazilian Plateau (Hershkovitz, 1990;Ribeiro et al, 2011). There is a parallel between the diversification of Podoxymys + Necromys + Thalpomys and species of vesper mice (Almeida et al, 2007): Calomys species are small-bodied sigmodontine rodents distributed throughout the dry-vegetation biomes in central South America. Under this scenario, we would expect the closest relatives of Podoxymys to live on adjacent tepui slopes or in the surrounding lowlands and uplands.…”

“…Phylogenetic trees were rooted using Sigmodontalia (Leite et al, 2014) as outgroups, based on the available phylogenies of cricetid rodents (Jansa & Weksler, 2004;Steppan et al, 2004;Schenk et al, 2013;Leite et al, 2014). The GTR model of nucleotide substitution (Rodr ıguez et al, 1990), corrected for site-specific rate heterogeneity using the gamma distribution with four classes (Yang, 1994), was used in ML and Bayesian analyses. Maximum-likelihood (ML) analyses were also applied to each gene individually.…”

“…Maximum-likelihood (ML) analyses were also applied to each gene individually. The GTR model of nucleotide substitution (Rodr ıguez et al, 1990), corrected for site-specific rate heterogeneity using the gamma distribution with four classes (Yang, 1994), was used in ML and Bayesian analyses. We employed gene-specific unlinked models and estimated nucleotide base frequencies empirically from the data.…”

Subsidies for a poorly known endemic semiarid biome of Brazil: non-volant mammals of an eastern region of Caatinga

“…Fluctuations of species richness and abundance of small non-volant mammals in environments under strong climatic seasonality have been extensively discussed (e.g., Mares et al 1989;Ribeiro et al 2011). In fact, this climatic variable must be taken into consideration, especially in environments with unpredictable and erratic rainfalls, where months or even years of drought may occur (Nimer 1972).…”