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Anthropogenic changes, such as land use and climate change, are the greatest threats to biodiversity, especially for reptiles, the second most endangered vertebrate class worldwide. Species distribution modelling was applied to assess how expected scenarios of future climate and land cover change might influence the geographic distribution and habitat connectivity of three Conopsisearthsnakes endemic to Mexico: Conopsis biserialis (Taylor and Smith, 1942),Conopsis lineata (Kennicott, 1859), and Conopsis nasus (Günther, 1858). In order to do this, two climate models were used, CNRM-CM5 (CN) and MPI-ESM-LR (MP), with the Representative Concentration Pathways of RCP 85 and the Maxent modelling method in ENMeval. The most important environmental variables affecting the distribution of the target species, as well as the environmental niche overlap between them, were also determined. C. biserialis, C. lineata, and C. nasus were found to be restricted by maximum and minimum temperatures as they are adapted to high elevations and temperate semi-cold climates; therefore, climate was a main determining factor for species distribution. As expected, all Conopsis species were predicted to face a reduction in their potential distribution with C. lineata possibly losing approximately 48.5% and C. biserialislosing 28.7%. However, the models were inconsistent in determining which species would suffer the biggest reduction in distribution in the future. Likewise, a reduction in connectivity was found for the three species of Conopsis, while the Sierra de las Cruces and Corredor Biológico Chichinautzin were determined as very important areas in terms of connectivity. Unfortunately, great losses of Abies and Pinus forests occurred in these areas between 2011 and 2014, along with an increase in the agricultural activity that compromises the populations of these species when intensively managed. Most of the potential distribution of these species are found in close proximity to agriculture and outside of protected areas, which is why it is extremely important to create protected areas for reptile species that live in these parts of central Mexico.

Anthropogenic changes, such as land use and climate change, are the greatest threats to biodiversity, especially for reptiles, the second most endangered vertebrate class worldwide. Species distribution modelling was applied to assess how expected scenarios of future climate and land cover change might influence the geographic distribution and habitat connectivity of three Conopsis earthsnakes endemic to Mexico: Conopsis biserialis (Taylor and Smith, 1942), Conopsis lineata (Kennicott, 1859), and Conopsis nasus (Günther, 1858). In order to do this, two climate models were used, CNRM-CM5 (CN) and MPI-ESM-LR (MP), with the Representative Concentration Pathways of RCP 85 and the Maxent modelling method in ENMeval. The most important environmental variables affecting the distribution of the target species, as well as the environmental niche overlap between them, were also determined. C. biserialis, C. lineata, and C. nasus were found to be restricted by maximum and minimum temperatures as they are adapted to high elevations and temperate semi-cold climates; therefore, climate was a main determining factor for species distribution. As expected, all Conopsis species were predicted to face a reduction in their potential distribution with C. lineata possibly losing approximately 48.5% and C. biserialis losing 28.7%. However, the models were inconsistent in determining which species would suffer the biggest reduction in distribution in the future. Likewise, a reduction in connectivity was found for the three species of Conopsis, while the Sierra de las Cruces and Corredor Biológico Chichinautzin were determined as very important areas in terms of connectivity. Unfortunately, great losses of Abies and Pinus forests occurred in these areas between 2011 and 2014, along with an increase in the agricultural activity that compromises the populations of these species when intensively managed. Most of the potential distribution of these species are found in close proximity to agriculture and outside of protected areas, which is why it is extremely important to create protected areas for reptile species that live in these parts of central Mexico.

Roberts’ False Brook Salamander (Pseudoeurycea robertsi) is a critically endangered plethodontid salamander, endemic to the Nevado de Toluca Volcano (NTV), Mexico. Little is known about the biology and ecology of this species, including its microhabitats. Thus, this study aimed to collect basic information about P. robertsi. We sampled fourteen forested sites in the NTV; to corroborate the correct identification of the species we used genetic data, we assessed the variation in head morphometric measurements and dorsal colouration patterns amongst localities and the microhabitat features associated with P. robertsi presence. Of the four potential salamander species, P. robertsi was the most abundant (89.80%) and widely distributed (approximately within 130 km2) salamander in the NTV. We did not find significant variations in morphometry; however, we found significant differences in dorsal patterns between populations (in the number and size of segments of the dorsal stripe). The average total length for 185 adults was 89.15 mm (38.7–117.9 mm); we found seven patterns of dorsal stripe. We found 98% of P. robertsi individuals under the bark of fallen logs in Abies religiosa and A. religiosa-Pinus sp. forests, with a higher number of detected salamanders in naturally-fallen logs than in cut logs (34% vs. 10%). Thus, keeping well-preserved A. religiosa forests and retaining fallen logs is essential to P. robertsi conservation.

Pseudocorynosoma constrictum (Van Cleave, 1918) is a polymorphid acanthocephalan that attaches to the digestive tract of waterfowl to complete its life cycle, causing severe histological damage to its definitive avian hosts. In the present study, we present a histopathological analysis of the lesions that P. constrictum induced in the layers of the ileum of the blue-winged teal Anas discors. The results revealed that worms insert the attachment structures into the inner gut muscular layer, which causes substantial swelling, haemorrhaging and necrosis in the tissue near the parasite's proboscis. We also observed that the number of parasites attached to the tissue can obstruct the intestinal lumen; in the most serious case, we observed more than 30 parasites penetrating completely the walls of the bird intestine.

Mexico is one of the most diverse countries that is losing a large amount of forest due to land use change, these data put Mexico in fourth place for global deforestation rate, therefore, Mexico occupies the first place in number of endangered species in the world with 665 endangered species. It is important to study amphibians because they are among the most threatened vertebrates on Earth and their populations are rapidly declining worldwide due primarily to the loss and degradation of their natural habitats. Pseudoeurycea robertsi is a micro-endemic and critically endangered Plethodontid salamander from the Nevado de Toluca Volcano and to date almost nothing is known about its natural history therefore, we survey fourteen sites of the Nevado de Toluca Volcano a mountain that is part of the Trans-Mexican Volcanic Belt, Mexico. We carry out the most exhaustive sampling scheme of this species throughout the Nevado de Toluca Volcano to know the number of individuals and the microhabitat features associated with the presence of P. robertsi. Likewise, we carry out a morphometric study and coloration measurements of P. robertsi individuals and we determine the potential distribution of P. robertsi and the other 3 species of pletodontids present in the NTV using ecological niche modeling and to determine the most important habitat features associated with the presence of salamander species, as well as to know the niche overlap among salamander species. This information will help raise conservation strategies for this micro-endemic and critically endangered salamander.