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.

In the Americas, infectious viral diseases caused by viruses of the genus Mammarenavirus have been reported since the 1960s. Such diseases have commonly been associated with land use changes, which favor abundance of generalist rodent species. In the Americas—where the rates of land use change are among the highest worldwide—at least 1326 of all 2277 known rodent species have been reported. We conducted a literature review of studies between 1960 and 2020, to establish the current and historical knowledge about genotypes of mammarenaviruses and their rodent reservoirs in the Americas. Our overall goal was to show the importance of focusing research efforts on the American continent, since the conditions exist for future viral hemorrhagic fever (VHF) outbreaks caused by rodent-borne viruses, in turn, carried by widely distributed rodents. We found 47 species identified down to the species level, and one species identified only down to the genus level (Oryzomys sp.), reported in the Americas as reservoirs of mammarenaviruses, most these are ecological generalists. These species associate with 29 genotypes of Mammarenavirus, seven of which have been linked to VHFs in humans. We also highlight the need to monitor these species, in order to prevent viral disease outbreaks in the region.

Urbanization implies the loss of biodiversity and promotes the extirpation of local flora and fauna. It favors habitat fragmentation and the establishment and increase of non-native species and, eventually, the homogenization of the landscape. This study aims to evaluate the urbanization process in a medium-sized city in the Mexican southeast, San Cristóbal de Las Casas (SCLC) in the Neotropics, and the response of the rodent community to such process.  The study area was categorized according to its structural characteristics into four coverage classes: urban, forest, agricultural and mountain wetlands. Rodents were sampled over urbanization gradients. In each gradient, nine sampling sites were established. The responses of rodent alpha and beta diversities to landscape structure (landscape metrics) were evaluated. The larger diversity of rodents was found in the mosaic and transition landscape categories and the least diverse were the conserved and urban ones. In SCLC, rodent richness responds to the number of fragments and the diversity of the landscape. Mus musculus and Rattus rattus were more abundant in landscapes with a high percentage of urban cover, while Peromycus mexicanus and P. beatae, in landscapes with higher forest cover. San Cristóbal de Las Casas is a city that grows over areas with native vegetation, forests and mountain wetlands; of which fragments remain embedded in the urban matrix. Mosaic and transition landscapes favor areas with high diversity and richness of rodent species (intermediate disturbance hypothesis). This study suggests that both native and non-native rodent species are abundant in areas with natural vegetation and also in urban sites. Sanitary measures are granted, since reservoir species of pathogens with zoonotic potential can be found in the area.

Amphibians are particularly sensitive to disturbances caused by urbanization. Urban disturbances impact amphibians at different ecological scales that include a decrease in biodiversity, increment of stress, and changes in vocal behavior. However, little is known about urban effects on terrestrial amphibians. In this study, we quantified abundance (by encounter rates) and species richness of amphibians, and the characteristics of their habitats in Pedregal del Xitle, a xerophytic ecosystem in Mexico City. In addition, we evaluated the vocal activity of Pedregal frogs under different noise exposures within the three protected areas. During 2015 and 2016 with the support of volunteers, several stratified direct night searches were conducted in three urban protected areas. Additionally, using a non-supervised classification of satellite images, we analyzed the coverage of the different vegetation types, and calculated the evenness of amphibians. With an effort of 238 person-hours, we located 73 individuals of amphibians, including three plethodontid salamanders (Aquiloeurycea cephalica, Chiropterotriton orculus and Pseudoeurycea leprosa), and the Pedregal frog, Eleutherodactylus grandis. Altogether, the captures of C. orculus and E. grandis represented 90% of the amphibians found. We found that 75% of the amphibians occupied the rocky ground microhabitat. The call rate of E. grandis was consistently lower at sites with the highest noise exposure. Among the three urban protected areas, Ecoguardas stands out as the one with the greatest abundance and diversity of amphibians and the largest proportion of forested area. Our study revealed the ecological value of the Pedregal ecosystem for terrestrial amphibians, since the most threatened species (the frog E. grandis and the salamander C. orculus) are those with the greatest presence in the urban protected areas studied.

Alopecia is the partial or total loss of hair in a mammal. This condition has been reported in 38 species of bats from 6 families. This report documents the presence of alopecia in an individual of Artibeus jamaicensis in the state of Veracruz, southeastern México. On September 25, 2022, during a field trip as part of a project to assess areas of zoonotic risk in the Mexican Neotropics, rodents and bats were captured in a medium semi-evergreen forest with shaded coffee plants in the peri-urban town of Berlín, municipality of Córdoba, Veracruz, México. Forty bats of different species were captured, including 1 adult male of A. jamaicensis with no evidence of reproductive activity and with alopecia in the head, neck, right shoulder, and chest. The area of the chest with alopecia also had a gelatinous lesion with a yellowish crust at the edges. This report represents the first record of alopecia in bats in Veracruz and the second for A. jamaicensis in México. In the A. jamaicensis individual examined, alopecia probably occurred as a result of a thoracic injury that spread to other parts of the body, likely due to a bacterial or fungal infection.