Differentiation and characterization of burrows of two species of armadillos in the Brazilian Cerrado

Abstract

Signs left by some mammals such as tracks, trails, burrows, scratches, feces, hair, and others can be an important tool for species identification. This study was conducted in the Itirapina Ecological Station, in the southern Brazilian Cerrado, whose main objectives were to (1) compare the burrow morphometric variables of Cabassous unicinctus and Euphractus sexcinctus and (2) check for differences in the occurrence of foraging burrows in two different environments: areas with vegetation (shrubby grassland) and areas without vegetation (roads). The collected measures of armadillo’s burrows have been width, height, depth, and angle relative to the soil. To record foraging burrows (<70 cm), the linear transect methodology was used simultaneously in roads and shrubby grassland environments. In a shrubby grassland environment of the Itirapina Ecological Station, a density of 121 burrows/ha pertaining to C. unicinctus and of 277 to E. sexcinctus was observed. Although there is overlap between them, morphometric variables were used to measure the burrows; significant differences were observed in all: depth, p < 0.001; ratio, p < 0.001; perimeter of the ellipse (perimeter), p < 0.001; and angle of excavation relative to the soil, p < 0.001. There was an observed interaction between the variables p < 0.001 for Wilk test. The PCA analysis evidenced two highly distinct groups of burrows, which corresponded to the initial visual classification. The variance explained by axes 1 and 2 was 83.18 %. The variable that most influenced the distinction of the burrows of the species was the perimeter. There was a density of 114 foraging burrows/ha across the roads and 42 in shrubby grassland. The results of the ANOVA, p < 0.05, and Tukey test, p < 0.05, demonstrate significant difference between the mean densities of foraging burrows in the said environments. This indicates that armadillos use the area devoid of vegetation to feed. Thus, this study provides information that can assist in the surveys of these species as well as to clarify aspects of its ecology in the Cerrado.