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Anthropogenic noise interferes with the acoustic signals of various wildlife species. For bats that use echolocation, noise can mask the information received in the echo. The effect of anthropogenic noise on the time and frequency components of echolocation pulses emitted by the aerial insectivorous bats Molossus sinaloae and Mormoops megalophylla in urban and natural habitats were evaluated. We hypothesized that the frequency components of pulses would increase in response to masking, while time components would not change significantly. To this end, acoustic recordings of both species were made in the two types of habitats using ultrasonic detectors; simultaneously, the intensity of the ambient noise was measured. Frequency (kHz) and time (ms) were analyzed for each echolocation pulse using the BatSound 4.2 software. Consistent with our hypothesis, the results showed that under background noise of 75 dB in an urban environment, M. sinaloae increased the low and high frequencies of its echolocation pulses by 5.8 kHz on average. For M. megalophylla, no increase in pulse frequencies was observed. Contrary to our expectation, the time components of pulses for M. sinaloae were modified, being of shorter duration in urban sites. Increasing the maximum amplitude-frequency by M. sinaloae may be a response to the Lombard effect, i. e., the increase in vocal amplitude in response to increased background noise. It is important to carry out studies focused on understanding the modification of echolocation pulses, mainly for species living in urban environments.

The volcano rabbit, Romerolagus diazi, is endemic to a small region along the Trans-Mexican Volcanic Belt in central Mexico. Although its distribution in the volcanic fields of the Sierras Nevada and Chichinautzin is not debated, its occurrence in the Nevado de Toluca volcano has been controversial. In this study, we used a species identification tool using DNA isolated from fecal pellets in order to corroborate the occurrence of volcano rabbit in the Nevado de Toluca. Both PCR assays and phylogenetic analysis of fragments of cytochrome b and D-Loop mitochondrial genes provide evidence that although the morphology of collected pellets resemble those of R. diazi, they instead correspond to a Sylvilagus species. These results support the hypothesis that R. diazi is not currently distributed in the Nevado de Toluca.

This work describes the echolocation pulses produced by Myotis velifer during postnatal development. The aim was to record the changes of these calls during the development of this bat species and investigate the underlying causes. Bat specimens were sampled in El Salitre cave, Morelos, Mexico, during May and June 2016, where juvenile bats were captured and sorted into five age classes. Forearm length was used as reference for offspring growth. Each juvenile bat was induced to fly and the echolocation calls produced were recorded using an ultrasound detector. Six quantitative characteristics of the echolocation pulses of each call were measured, which served as reference to explore the development of this system during growth through a linear regression. A steady increase in the frequency parameters associated with bat growth was observed, coupled with a decrease in the temporal parameters. The final pulse frequency was the only parameter that remained unchanged during postnatal growth. The major changes in the characteristics of echolocation pulses during postnatal growth in M. velifer follow the pattern observed in other species previously studied. These changes are likely related to the development of organs and muscles involved in the emission and reception of sound, and to the learning process involved in the use of this adaptation.

Endemic to the central mountains of the Trans-Mexican Volcanic Belt, the volcano rabbit (Romerolagus diazi), known locally as the zacatuche, is a threatened species at risk of extinction. In the Ajusco-Chichinautzin Mountain Range, the Pelado and Tlaloc volcanoes are core distribution areas for this species; however, suitable habitat within these areas is patchy. We analyzed the habitat of this species at the landscape level, taking into account biotic, abiotic, and anthropogenic factors. We used geographic information systems for the habitat analysis and a linear mixedeffects model to identify the habitat patches available, analyze them in the FRAGSTATS program, and calculate their landscape metrics. To identify the habitat of the volcano rabbit, we used its relative abundance index in the context of land use and vegetation, elevation, slope, road and highway density, and distance to human settlements. The analyses indicated that the relative abundance index of this species decreases with increasing proximity to human settlements and with increasing road and highway density. At the landscape level, there are 957 patches of habitat available to the species, covering 75.44 km2. Most of the patches are 2,500 m2 in area and regular in shape (square); however, because they are small patches it is possible that they will disappear. The largest patches are located on the Pelado and Tlaloc volcanoes, and coincide with the core distribution areas of the volcano rabbit described in the literature.

Bat acoustic libraries are important tools that assemble echolocation calls to allow the comparison and discrimination to confirm species identifications. The Sonozotz project represents the first nation‐wide library of bat echolocation calls for a megadiverse country. It was assembled following a standardized recording protocol that aimed to cover different recording habitats, recording techniques, and call variation inherent to individuals. The Sonozotz project included 69 species of echolocating bats, a high species richness that represents 50% of bat species found in the country. We include recommendations on how the database can be used and how the sampling methods can be potentially replicated in countries with similar environmental and geographic conditions. To our knowledge, this represents the most exhaustive effort to date to document and compile the diversity of bat echolocation calls for a megadiverse country. This database will be useful to address a range of ecological questions including the effects of anthropogenic activities on bat communities through the analysis of bat sound., The Sonozotz project represents the first nation‐wide library of bat echolocation calls for a megadiverse country.

We propose in this work a novel approach aiming at assessing cause and effect relationships between variables that can affect target biodiversity issues. These cause–effect relations are used to build a network whose nodes represent variables linked by directed arcs. The arcs have associated a value that represents trends of cause–effect relations. An important novelty of this approach is the use of product and addition operations between trends of cause–effect relations for assessing factors that can affect target variables. For the analysis of the network we use the concept of paths. Paths are defined as sequences of cause–effect relations from source variables to target variables. For example, the path from population increment that causes effects on the increment of transport routes, which in turn causes effects on the loss of vegetation cover. This approach was applied to the assessment of vegetation cover in the Morelos State, Mexico during the period 2000–2010. The results show a promising practical alternative to assess the potential effects on biodiversity issues based on the analysis of the paths represented in the network.

Introduction: Predation may have important effects on prey populations, especially when the prey species is considered endangered such as the volcano rabbit (Romerolagus diazi). Understanding the importance of the volcano rabbit in the coyote and bobcat diet is important to recognize the possible impact that thesepredators can have on the populations of this endangered rabbit. Methods: We studied the food habits of the coyote and during three climate seasons in the Chichinautzin Biological Corridor through scat analysis. We obtained the frequency of occurrence and consumed biomass of each identified prey item. Additionally we estimated the relative abundance of some of the potential prey species for these two predators and analyzed the relationship between prey abundance and the use of the prey found on the diet of these two predators. Results: The most common prey species and with the greatest biomass contribution on the diet of coyotes and bobcats were the rabbits of the genus Sylvilagus sp., followed by the volcano rabbit. We did not find differences in the frequency of occurrence of prey or in the consumed biomass between the studied seasons, indicating that the diet of both predators remains constant throughout the year. Prey selection analysis showed that both predators selected Sylvilagus rabbits, while volcano rabbits are consumed less than their availability in the environment. Discussion and conclusions: Reduced consumption of the volcano rabbit according with their availability on the environment by coyotes and bobcats could be the result of the selection of larger prey and the nocturnal behavior patterns of both predators. Even though we did not find that both predators are selecting volcano rabbits on their diets, our results showed that coyotes and bobcats are important predators for R. diazi. It is necessary to determine the potential number of volcano rabbits consumed by both predators in order to understand the impact of these predators on this endangered species.

Nine new records of flowering plants are reported for Morelos state, Mexico. Most of the species occur at the Biological Corridor Chichinautzin and the Biosphere Reserve Sierra of Huautla, located at north and south of Morelos state, respectively. A brief diagnosis, phenology, notes and illustrations are included. These records are the outcome of floristic studies carried out by the authors in both natural reserves.

Changes in the environment are a common factor as human populations continue to increase. Wild mammals face these changes even in those places where they live under protection because protected areas borders are not hermetic. Measurements of faecal cortisol metabolites have become a useful tool for monitoring animal physiological status as they reflect stressful situations. In this study we measured faecal cortisol metabolites in volcano rabbits, Romerolagus diazi, inhabiting a natural protected area. Concentrations were compared between animals inhabiting disturbed vs. more natural sites within the general zone. Not only were faecal cortisol metabolites levels significantly higher in animals from the disturbed sites indicating potentially higher physiological stress intensities, but there was larger variation between the concentrations measured in those samples as well. These inter-individual cortisol metabolites concentrations are a potential indicator of physiological health for wildlife.

The volcano rabbit Romerolagus diazi is endemic to the mountains of central Mexico, where its habitat has been gradually destroyed to make way for agriculture, ranching and logging, and by forest fires. The volcano rabbit is categorized as Endangered on the IUCN Red List. We evaluated the relationship between the abundance of the volcano rabbit and vegetation structure at a small scale (0.25 ha). Using a general linear model we generated a set of 21 predictive models and proposed the best model as a habitat quality index. Our results suggest that greater height and cover of bunchgrasses and the presence of a shrub layer offer the volcano rabbit the best refuge from predators. The habitat quality index and the limited available habitat documented in our survey indicate that the populations of volcano rabbits in the study area are more threatened than previously thought. As R. diazi is a habitat specialist it does not have the option of moving to another habitat type.

Little is known about the social structure of the molossid bats in the Neotropics. During 4 observational periods (2006/2007), we studied the spatial distribution and temporal variation of a colony of Nyctinomops laticaudatus inside the Governor’s Palace at the Archeological Zone of Uxmal, Yucatan, Mexico. We surveyed 66 roosting cavities consisting of mixed groups of males and females. This particular association (mixed groups) occurred throughout the study, but bats shifted group membership by moving continuously from one group to another. Because of this pattern, we were unable to describe a unique social structure and we proposed a promiscuous system for the species. During the 2 year study, we identified only adult bats inside cavities, while newborns were observed roosting outside cavities in adjcent walls. Resting was the most common activity inside cavities, but visits and copulations were also recorded. In groups of Nyctinomops laticaudatus both sexes are presented and differ with other bats due to their lower degree of cohesiveness.

The Protected Natural Area (PNA) “Corredor Biologico Chichinautzin” contains a large area of bunchgrasses, a habitat that is necessary for the zacatuche rabbit to survive. As part of a monitoring program used to evaluate the status of the zacatuche rabbit’s populations within this PNA, we estimated its distribution by using direct (sightings) and indirect methods (latrines) during visits performed to all the available habitats. Additionally, we estimated the annual density of the zacatuche rabbit using a line transect method, sampling eight, one-kilometer-long transects monthly during one year. Based on 101 latrine records and 48 sightings, a distribution map was prepared for the region using the convex polygon method in ArcView. Most of this distribution (166.43 km 2 ) represents an area that had not been previously reported in the literature for the zacatuche rabbit. Using the half-normal model that best fit the data, we estimated a density of 4.2 rabbits/ha. Our results suggest that the Corredor Biologico Chichinautzin meets the criteria necessary to be cataloged as a core distribution area for the zacatuche rabbit. Therefore, we suggest that both management and conservation of this habitat within the PNA should be made a priority. El Area Natural Protegida (ANP) “Corredor Biologico Chichinautzin” contiene una extensa area de pastizales amacollados, un habitat que es necesario para que el zacatuche sobreviva. Como parte de un programa de monitoreo para evaluar el estado de las poblaciones del conejo zacatuche en esta ANP, estimamos su distribucion utilizando metodos directos (avistamientos) e indirectos (letrinas) durante visitas a todos los habitats disponibles. Ademas, se estimo su densidad anual utilizando el metodo de transectos lineales, muestreando cada mes ocho transectos de un km de largo durante un ano. Con base en los registros de 101 letrinas y 48 avistamientos, se elaboro un mapa de distribucion para la region mediante el metodo del poligono convexo en ArcView. La mayor parte de esta distribucion (166,43 km 2 ) representa un area que no habian sido previamente reportada en la literatura para el zacatuche. Usando el modelo half-normal que fue el mejor que se ajusto a los datos, se estimo una densidad de 4.2 conejos/ha. Nuestros resultados sugieren que el Corredor Biologico Chichinautzin cumple con los criterios necesarios para ser catalogado como un area nucleo de distribucion para el zacatuche. Por lo tanto, sugerimos que el manejo y la conservacion de este habitat en el ANP deben ser una prioridad.