The value of xeroriparian habitats in the Llanos de Ojuelos, southern portion of the central plateau of Mexico in the light of new mammal records

Resumen

The Llanos de Ojuelos, in the southern part of the central plateau of Mexico is a complex, semiarid, anthropized landscape, in which native habitats persist as remnants within a diffuse farmland matrix. Approximately 0.1% of the landscape is covered by riparian habitats, which in arid and semiarid regions are known as xeroriparian. They are mostly fragmented remnants of a historically much larger xeroriparian network. Xeroriparian habitats generally play a disproportionate role as wildlife habitat, although their value for many groups, including mammals, has not been assessed in the southern part of the central plateau of México. Since 2003 we conducted some opportunistic observations in xeroriparian habitats, and from 2017 to 2023 we deployed 15 automatic trail cameras at five xeroriparian systems for different periods of time. We also surveyed these and other such systems in search of mammal signs. Among the many species whose records we obtained, those of Virginia opossum (Didelphis virginiana), nine-banded armadillo (Dasypus novemcinctus), ringtail (Bassariscus astutus), American badger (Taxidea taxus), puma (Puma concolor), collared peccary (Pecari tajacu), and Peters´ squirrel (Sciurus oculatus) were important in improving our understanding of the conservation value of xeroriparian systems. They either were new records for these systems or complemented the scanty data previously generated. The data fill important information gaps on mammal distribution and habitat use and contribute to a better knowledge of the mammal composition of the region and the conservation role of its xeroriparian systems. Some species, such as the American badger and ringtail, may have always inhabited the region, but remained undetected due to their cryptic nature. Others, like the puma and collared peccary, appear to be recolonizing large areas from which they had been extirpated. In contrast, at least the armadillo seems to be a recent colonizer. The origin of Peters´ squirrel requires further study. Although much remains unknown about the value of xeroriparian habitats in the southern part of the central plateau of Mexico for mammals, their disappearance, reduction, or strong transformation would impact this group negatively. Our new data underscore that despite the extended anthropization of the Llanos de Ojuelos, xeroriparian habitats play an important role in the conservation of mammalian biodiversity.