Mammals of the Tamaulipeco Thorny Scrubland, Northwestern Coahuila, Mexico

Abstract

The 'Tamaulipeco' thorny scrubland is one of the most interesting habitats of northeastern Mexico. It is considered that almost 70 % of its original surface area has been lost. Although there are no formal studies about the side effects of this loss, it is likely that it threatens wildlife in this habitat, mammals included. In addition, few areas in the State of Coahuila have been properly documented. The aim of this study was to document the richness of wild mammals in the northeastern border of Coahuila within the priority terrestrial region known as "Tamaulipeco Scrubland of the Lower Rio Bravo". The richness of mammals was assessed through direct records by trapping methods for small, medium-sized and large mammals along with the use of camera traps. This was supplemented with indirect records through traces. The occurrence index and richness of the area index were calculated. In addition, dominance and evenness were both evaluated with the Simpson and the Shannon-Wiener indexes for small and medium-sized/large mammals separately. Thirty three mammal species (Table 2) were recorded in 34 days of recording effort. The richness recorded in the study area represents 31.8 % of the mammal wildlife reported for Coahuila. The high diversity in the area is evidenced by the Margalef index (5.13). The Simpson index for small mammals (0.241) indicates a higher dominance in relation to medium-sized/large mammals (0.215). The Shannon-Wiener index showed a lower evenness among small relative to medium-sized /large mammal species (1.821 vs. 1.858). The species richness recorded in the study area shows a high diversity supported by the Margalef index. Despite characteristics of some of the observed traces are inarguable for specie's identification index does not confirm its presence due to low indirect records, so the certain presence of these species need to be confirmed in future surveys. The large number of records for Dicotyles angulatus and Odocoileus virginianus is due to the location of the study area in a hunting zone were these are the main species hunted. It is likely that hunting activities by local inhabitants benefits the rest of the species recorded.