General Microbiota of the Soft Tick Ornithodoros turicata Parasitizing the Bolson Tortoise (Gopherus flavomarginatus) in the Mapimi Biosphere Reserve, Mexico

The general bacterial microbiota of the soft tick Ornithodoros turicata found on Bolson tortoises (Gopherus flavomarginatus) were analyzed using next generation sequencing. The main aims of the study were to establish the relative abundance of bacterial taxa in the tick, and to document the presence of potentially pathogenic species for this tortoise, other animals, and humans. The study was carried-out in the Mapimi Biosphere Reserve in the northern-arid part of Mexico. Bolson tortoises (n = 45) were inspected for the presence of soft ticks, from which 11 tortoises (24.4%) had ticks in low loads (1–3 ticks per individual). Tick pools (five adult ticks each) were analyzed through 16S rRNA V3–V4 region amplification in a MiSeq Illumina, using EzBioCloud as a taxonomical reference. The operational taxonomic units (OTUs) revealed 28 phyla, 84 classes, 165 orders, 342 families, 1013 genera, and 1326 species. The high number of taxa registered for O. turicata may be the result of the variety of hosts that this tick parasitizes as they live inside G. flavomarginatus burrows. While the most abundant phyla were Proteobacteria, Actinobacteria, and Firmicutes, the most abundant species were two endosymbionts of ticks (Midichloria-like and Coxiella-like). Two bacteria documented as pathogenic to Gopherus spp. were registered (Mycoplasma spp. and Pasteurella testudinis). The bovine and ovine tick-borne pathogens A. marginale and A. ovis, respectively, were recorded, as well as the zoonotic bacteria A. phagocytophilum,Coxiella burnetii, and Neoehrlichia sp. Tortoises parasitized with O. turicata did not show evident signs of disease, which could indicate a possible ecological role as a reservoir that has yet to be demonstrated. In fact, the defense mechanisms of this tortoise against the microorganisms transmitted by ticks during their feeding process are still unknown. Future studies on soft ticks should expand our knowledge about what components of the microbiota are notable across multiple host–microbe dynamics. Likewise, studies are required to better understand the host competence of this tortoise, considered the largest terrestrial reptile in North America distributed throughout the Chihuahuan Desert since the late Pleistocene.

Individual variation in mule deer (Odocoileus hemionus) habitat and home range in the Chihuahuan Desert, Mexico

Historically, mule deer (Odocoileus hemionus) had a distribution area as large as the Chihuahuan Desert in Mexico, but in recent years, its populations have decreased and distribution areas have become isolated. This species exhibits a high degree of intraspecific variation in its use of habitat resources and home range size. In the Mapimí Biosphere Reserve, where the southernmost population of mule deer is located, over the course of 3 years, 7 females and 1 young male mule deer were monitored using radiotelemetry. Based on the deer location data, home range and habitat use were estimated for each deer. The mean (± SD) home range size for females was 14.70 km2 (± 5.89), the home range of the male was 18.05 km2. These estimates are among the smallest reported for the species. During the dry season, the use of certain topographic characteristics of the habitat was more similar among the individual deer than it was during the rainy season. The group of deer we sampled did not show preference for any particular type of vegetation, but rather used the majority of plant associations, depending on their availability. Preference was only exhibited by individual deer. The young male made use of the habitat similar to that of most of the females. El venado bura (Odocoileus hemionus) históricamente tenía un área de distribución tan grande como el Desierto Chihuahuense de México, sin embargo, en los últimos años sus poblaciones y áreas de distribución se han visto reducidas y aisladas. Se sabe que la especie exhibe gran variación intraespecífica en el uso de los recursos del hábitat y en los ámbitos hogareños. Dentro de la Reserva de Biosfera de Mapimí donde se encuentra la población más sureña de los venados buras, a lo largo de 3 años se monitorearon mediante radiotelemetría, 7 hembras y 1 macho joven de venado bura. Utilizando las localizaciones se estimaron los ámbitos hogareños y el uso del hábitat de cada animal. El promedio (± DE) del tamaño del ámbito hogareño para las hembras fue de 14.70 km2 (± 5.89), el tamaño del ámbito hogareño del macho fue de 18.05 km2. Estas estimaciones son de las áreas más pequeñas reportadas para la especie. Durante la temporada de secas el uso de las características topográficas del hábitat entre individuos fue más parecido entre ellos que en lluvias. Entre el conjunto de venados que muestreamos, no se presentó preferencia por alguna asociación vegetal en particular, los individuos usan la mayoría de las asociaciones vegetales de acuerdo a su disponibilidad, las preferencias únicamente se observaron a nivel individual. El macho joven hizo un uso del hábitat similar al que hicieron la mayoría de las hembras.