Mexico is home to 14 species of lagomorphs, 6 of which are endemic. Studies on diseases affecting native lagomorphs are scarce, and in most cases, the impact on their populations remains largely unknown. Rabbit hemorrhagic disease virus (RHDV), especially the RHDV2 variant, causes a serious and extremely contagious disease, resulting in high mortality rates and major declines in wild lagomorph populations. The objectives of this study were to identify disease hotspots and critical biodiversity regions in Mexico through the combined use of disease information and lagomorph distribution maps and to determine the areas of greatest concern. In total, 19 states of Mexico recorded RHDV2 from April 2020 to August 2021, and 12 of them reported the wild species Sylvilagus audubonii, Lepus californicus, and unidentified Leporidae species. The distribution of RHDV2 in Mexico can be closely predicted from climatic variables. RHDV2 hotspots are located in the central-southern area of the Mexican Highlands and the Trans-Mexican Volcanic Belt, where the virus affects multiple species. This knowledge is essential for proposing specific actions to manage and preserve lagomorph populations at risk and address these issues as soon as possible.

The SARS-CoV-2 coronavirus is the focus of attention as it has caused more than three million human deaths globally. This and other coronaviruses, such as MERS-CoV, have been suggested to be related to coronaviruses that are hosted in bats. This work shows, through a bibliographic review, the frequency of detection of coronavirus in bats species of the Americas. The presence of coronavirus in bats has been examined in 25 investigations in 11 countries of the Americas between 2007 and 2020. Coronaviruses have been explored in 9371 individuals from 160 species of bats, and 187 coronavirus sequences have been deposited in GenBank distributed in 43 species of bats. While 91% of the coronaviruses sequences identified infect a single species of bat, the remainder show a change of host, dominating the intragenera change. So far, only Mex-CoV-6 is related to MERS-CoV, a coronavirus pathogenic for humans, so further coronavirus research effort in yet unexplored bat species is warranted.

We analyzed morphometric and molecular variation among 8 populations of Peromyscus zarhynchus grouped into 5 pooled samples representing separate physiographic regions across the range of this species in Chiapas, Mexico, and western Guatemala. Mitochondrial sequence data identify 2 well-supported and reciprocally monophyletic clades, separating all Chiapas specimens from those in Guatemala. These 2 clades group as a strongly supported monophyletic lineage aligned with other members of the Peromyscus mexicanus species group. The Chiapas clade is further subdivided into 4 subclades: 1) samples from the western part of the state, 2) specimens from a single locality in Northern Chiapas, 3) all central localities, and 4) those from a single locality in Eastern Chiapas. The molecular distance in the mitochondrial cytochrome-b gene (Cytb) between the 2 major clades is relatively low (mean p-distance = 3.66%); those between the 4 Chiapas subclades are even less (mean p-distance 2.73%). Multivariate analyses of external and craniodental morphometric variables also distinguish 2 major groups, separating Guatemalan from Chiapas samples but with the latter also divided into 2 subgroups, one that segregates the Northern Chiapas sample from those distributed elsewhere in that state. The Guatemalan and Chiapas samples differ in both cranial size and shape variables. The second-level separation of samples from within Chiapas (northern versus all others) is interpreted to result from the combination of local adaptation to distinct physiographic regions and geographic isolation generated by patches of suitable habitat. We describe the Guatemalan samples as a distinct species based on their molecular and morphological uniqueness, and argue that P. zarhynchus itself is divided into definable subspecies, with the nominotypical form P. z. zarhynchus, restricted to the vicinity of its type locality (Tumbalá) in Northern Chiapas, and P. z. cristobalensis with type locality of San Cristobal, over the remainder of the species range in the state. Analizamos la variación morfométrica y molecular en 8 poblaciones de Peromyscus zarhynchus, agrupadas en 5 diferentes regiones fisiográficas a lo largo de la distribución de la especie en Chiapas, México, y el oeste de Guatemala. Los datos de secuencias mitocondriales identifican 2 clados monofiléticos recíprocos que separan a todos los individuos de Chiapas de aquellos de Guatemala; estos dos clados están agrupados como un linaje monofilético junto a otros miembros del grupo Peromyscus mexicanus. El clado de Chiapas está además subdividido en 4 subclados geográficos: (1) oeste, (2) norte, (3) todas las localidades del centro, y (4) este. La distancia molecular en el gen mitocondrial citocromo b (Cytb) entre los 2 clados principales es relativamente baja (distancia media p = 3.66%); mientras que entre los 4 subclados de Chiapas es aún menor (distancia media p = 2.73%). Los análisis multivariados de las variables externas y morfométricas también distinguen 2 grandes grupos, separando a las muestras de Guatemala de las de Chiapas; esta última es divisible en 2 subgrupos, uno con la muestra del norte de Chiapas y el segundo con aquellos distribuidos en otras partes del estado. Las muestras de Guatemala y Chiapas difieren en tamaño y forma craneal. El segundo nivel de separación de las muestras de Chiapas (norte contra todos los demás) es interpretado como resultado de la combinación de adaptación local a distintas regiones fisiográficas y aislamiento geográfico generado por parches de hábitat adecuado. Describimos a los ejemplares guatemaltecos como una especie distinta basada en su singularidad molecular y morfológica, y argumentamos que P. zarhynchus en sí mismo es divisible en subespecies definidas, con la forma nominotípica (P. z. zarhynchus) restringida a los alrededores de su localidad tipo (Tumbalá) en el norte de Chiapas y P. z. cristobalensis, con localidad tipo en San Cristóbal, para el resto de la distribución de la especie en el estado.

Effect of Climate Change on the Distribution of a Critically Threatened Specie

We assessed the patterns of diversity, richness, abundance, and dissimilarity in rodent and bat communities for four sites on the Isthmus of Tehuantepec in Oaxaca, Mexico, an important region given the enormous number of endemic Neotropical species. The main objective was to examine rodent and bat community parameters relative to habitat diversity and human habitat disturbance in a fragmented landscape. We captured 1,133 individuals of 13 rodent species and 26 bat species from January to August 2006. The site (landscape unit) with greatest habitat diversity also had the highest diversity of rodents. Species dissimilarity was low between sites that had similar degrees of human disturbance. For rodents, species dissimilarity between habitats on the Isthmus of Tehuantepec landscape was generally high; therefore, the species are not distributed evenly across the entire landscape. For bats, the degree of species dissimilarity between the different habitats of the landscape was low. The distribution of bat species across the landscape is a reflection of their high vagility and the spatial structure of the landscape. The results show the importance of a diversity of habitats to the patterns of richness, abundance, and dissimilarity of mammals in the study area.

The antelope jackrabbit, Lepus alleni occurs from south-central Arizona, southward to northern Nayarit, Mexico. In Arizona and the northern part of Sonora the species is sympatric with Lepus californicus. Lepus alleni belongs to the white-sided jackrabbit group of the genus, which separated from a common ancestor to Lepus californicus ∼1.2 MYBP. Genetic evidence indicates that this white-sided jackrabbit group separated into at least three species during the Pleistocene, while L. californicus expanded its range. We contend that L. alleni is a tropic-subtropic species restricted to remnant savannas and those more mesic portions of the Sonoran Desert where summer precipitation and humidity are adequate, and to areas of maritime dew lacking L. californicus. Not only is L. californicus better adapted to aridity, this species is also able to tolerate relatively cold temperatures. L. alleni is confined to habitats having mean annual temperatures between 20°C and 60°C, and goes into hypothermia when bod...