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Leopardus wiedii and Leopardus pardalis are endangered small felids. Its main altitudinal range expands from sea level to 1,500 m. Camera traps were placed in the Matawi Indigenous Park on the Nevado de Toluca Volcano. Photographic records were obtained of L. wiedii at 3,207 masl and of L. pardalis at 3,307 masl. This is the highest altitudinal record for margay in its distribution, and for ocelot is the highest in the northern hemisphere. [ABSTRACT FROM AUTHOR]

One of the most obvious impacts of roads is roadkill, a problem that is recently being addressed in Mexico. However, there are economic and human resource limitations to monitor the entire road network, assess its impacts, and propose mitigation measures. The black bear (Ursus americanus) is a top predator and the largest terrestrial mammal distributed in Mexico, currently the only of the Ursidae family. In recent years, its presence near human settlements and incidents on roads has increased. We generated a single MaxEnt model to identify characteristics of sites with high black bear roadkill risk and to identify these areas within protected natural areas. We obtained 83 bear roadkill records between 2008 and 2022, and we used a set of 16 variables that included landscape, road variables, and human variables. The model had an area under curve value of 0.96 indicating good performance and the Jacknife analysis identified influence on the roadkill risk of the distance to water bodies, protected areas, scrubland, drainages, and speed limit. We identified 3883.25 km of roads at high roadkill risk for black bears of which, 373.10 (9.6%) km were inside protected areas. We suggest placing speed bumps and effective signage on high-risk sections as a short-term, low-cost strategy. The results help to focus conservation efforts to specific sections of the road network, as roadkill is an increasing source of mortality that has not been evaluated for black bear in Mexico. This information is applicable for mitigating the impacts of existing roads and for planning new projects that have less impact on wild black bear populations and, at the same time, increase the safety of vehicle drivers. [ABSTRACT FROM AUTHOR]

Context: Land use change, habitat loss and fragmentation are the major threats to jaguar conservation in Latin America. Here, we integrate the information of jaguar's distribution to identify priority areas for its conservation. Objective: We evaluated the effect of topographic, anthropogenic and landscape variables on habitat suitability to evaluate potential core areas and biological corridors for jaguar conservation across Mexico. Methods: We compiled a database of jaguar occurrence records, geospatial data-set of all Natural Protected Areas and using the expert criterion of the Mexican jaguar specialists to define Jaguar Geographic Regions; i.e. well-defined large units with similar ecological characteristics across the geographic range of jaguars in Mexico. We then conducted analyses of ecological niche models to identify Jaguar Conservation Units; i.e. core units with jaguar populations of 15 or more individuals. We used Least Cost Path and Circuit Theory analyses to define the Biological Corridors; i.e. regions with enough habitat to allow for jaguar dispersal along their geographic range, but putting emphasis in connecting Jaguar Conservation Units. Results: We identified 5 Jaguar Geographic Regions (JGRs), 10 Jaguar Conservation Units (JCUs), and 13 Biological Corridors to maintain the connectivity of jaguar's populations across their whole geographic range in Mexico. Our results showed that JGRs cover 25% of the country but only 21% of those regions are currently protected in nature reserves. So, our study illustrates the importance of the creation of new protected areas or the implementation of other schemes of conservation to protect larger extensions of the jaguars' habitat in Mexico. It also indicates that despite the reduction of jaguar range in Mexico, there are still relatively large and well conserved areas capable of maintaining jaguar populations. Conclusions: Our results are a fundamental tool to guide the conservation and management of jaguars in Mexico. Our findings indicate that public jaguar conservation policy to protect the remaining jaguar habitat in Mexico should include the following actions: i) Strengthen established protected areas, ii) Create new protected areas, iii) Implement sustainable development programs to stimulate land owners to protect their lands, and iv) Develop mitigation measures for infrastructure. Although the window of opportunity is closing, our results indicate that there is still time to save jaguars and the plethora of species that share their habitat in Mexico. [ABSTRACT FROM AUTHOR]

Species coexistence at a given locality generally implies segregation along one of the three resource dimensions of the ecological niche: spatial, trophic or temporal. Temporal activity patterns of species are ecologically important as they expose how species exploit their environments. Using camera traps, we evaluated the temporal activity patterns and temporal overlap for a mammalian carnivore assemblage from Sierra Nanchititla Natural Park, central Mexico. We characterized and compared temporal activity patterns and temporal overlap between species pairs using circular statistics. Temporal overlap was analyzed using three temporal domains (full diel, diurnal, and nocturnal), and null models were used to contrast the empirical assemblage-wide temporal overlap in relation to randomly generated distributions. We found that pair-wise temporal overlap comparisons among species were quite heterogeneous and dependent on the temporal domain used for the analyses. Two major inferences can be derived from pair-wise analyses and the null model: (a) most of the carnivore assemblage show a nocturnal activity pattern in common and (b) most of the pair-wise comparisons indicate temporal segregation among species. The highest temporal overlap at the assemblage-wide level was found when only the nocturnal domain was evaluated and we found coincident temporal activities at the full domain level, independent of the temporal resolution used. Overall, our results suggest that carnivores with distinct trophic and habitat use like the margay (Leopardus wiedii) and gray fox (Urocyon cinereoargenteus) had temporal overlapping activity patterns to full diel and nocturnal domains, and species with similar trophic and habitat use always presented temporal segregation (gray fox and white-nosed coati, Nasua narica). Finally, species with predator-prey relationships (white-nosed coati and cougar, Puma concolor) showed segregation during the day but overlap at night. Our results indicate that species temporal activity patterns likely change in relation to different interspecific interactions such as predation and competition to allow species coexistence within this carnivore assemblage. [ABSTRACT FROM AUTHOR]

Land use changes are threatening the maintenance of biodiversity. Genetic diversity is one of the main indicators of biological diversity and is highly important as it shapes the capability of populations to respond to environmental changes. We studied eleven populations of Pseudoeurycea robertsi, a micro-endemic and critically endangered species from the Nevado de Toluca Volcano, a mountain that is part of the Trans-Mexican Volcanic Belt, Mexico. We sequenced the mitochondrial cytochrome b gene from 71 individuals and genotyped 9 microsatellites from 150 individuals. Our results based on the cytochrome b showed two divergent lineages, with moderate levels of genetic diversity and a recently historical demographic expansion. Microsatellite-based results indicated low levels of heterozygosity for all populations and few alleles per locus, as compared with other mole salamander species. We identified two genetically differentiated subpopulations with a significant level of genetic structure. These results provide fundamental data for the development of management plans and conservation efforts for this critically endangered species. [ABSTRACT FROM AUTHOR]

Information about human land uses, producing the least impact on wildlife and their habitats, is crucial to develop management strategies allowing coexistence between human beings and wildlife. We investigated the responses of the bobcat (Lynx rufus) and the coyote (Canis latrans) to different types of human activity by assessing the abundance, habitat use, and activity patterns of these species in response to extraction of firewood, grazing, and crop farming within their habitat. Photographic records of both carnivores were obtained from 18 camera-trap stations, distributed evenly within these three types of habitat disturbances. The highest relative abundance index for both carnivores was obtained at firewood extraction sites, followed by grazing sites, and croplands. The probability of carnivore sightings varied between species by type of disturbance and by season. The probability of bobcat sightings was highest within firewood extraction sites, with no effect of season, whereas that of the coyote was highest during winter, with no effect of type of human disturbance. An analysis of habitat use revealed that both carnivores avoided cropland sites. Activity patterns were similar, which suggests an absence of temporal segregation between these species; moreover, the activity patterns of both carnivores seems to be affected by intensity of human activities. Preference for woodland habitats by both carnivores denotes that firewood extraction is the disturbance that least affects bobcat and coyote populations; therefore, this kind of human activity could be the least impacting type of disturbance for the coexistence between humans and these carnivore species. [ABSTRACT FROM AUTHOR]

The isolated and fragmented populations are highly susceptible to stochastic events, increasing the extinction risk because of the decline in putative adaptive potential and individual fitness. The population has high heterozygosity values and a moderate allelic diversity, the heterozygosity values are higher than in most other Crotalus species and snake studies. Possibly these high levels of genetic diversity can be related to a large founder size, high effective population size, multiple paternity and overlapping generations. We did not find the genetic structuring but the effective number of alleles (Ne) was 138.1. We found evidence of bottlenecks and the majority of rattlesnakes were unrelated, despite the small sample size, endemic status, the isolated and fragmented habitat. The genetic information provided in this study can be useful as a first approach to try to make informed conservation efforts for this species and also, important to preserve the habitat of this species; the endangered Abies-Pinus forest of the Nevado the Toluca Volcano. [ABSTRACT FROM AUTHOR]

Amphibians are globally threatened by habitat loss and fragmentation; species within the order Ambystoma are not the exception, as there are 18 species of mole salamanders in México, of which 16 are endemic and all species are under some national or international status of protection. The mole salamander, Ambystoma altamirani is a microendemic species, which is distributed in central México, within the trans-Mexican volcanic belt, and is one of the most threatened species due to habitat destruction and the introduction of exotic species. Nine microsatellite markers were used to determine the genetic structure, genetic variability, effective population size, presence of bottlenecks and inbreeding coefficient of one population of A. altamirani to generate information which might help to protect and conserve this threatened species. We found two genetic subpopulations with significant level of genetic structure (FST = 0.005) and high levels of genetic variability (Ho = 0.883; He = 0.621); we also found a small population size (Ne = 8.8), the presence of historical (M = 0.486) and recent bottlenecks under IAM and TPM models, with a low, but significant coefficient of inbreeding (FIS = -0.451). This information will help us to raise conservation strategies of this microendemic mole salamander species. [ABSTRACT FROM AUTHOR]

Top-down and bottom-up controls are hypothesized to regulate population structures in many ecosystems. However, few studies have had the opportunity to analyze both processes in the natural environment, especially on large carnivores like the cougar ( Puma concolor). Previously, studies show that cougar diet in the Sierra Nanchititla Natural Reserve (SNNR), central Mexico, is mainly armadillo, coati, and white-tailed deer. We assess whether top-down and/or bottom-up control regulate this endangered food web: (a) we predicted that seasonal per capita changes in abundance ( pca) of cougar will be positively affected by the abundance of their main prey; (b) primary productivity in SNNR will affect the pca of prey species, driving bottom-up control; and (c) armadillo, coati, and white-tailed deer pca will be affected by the abundance of cougar, generating top-down control. Using 15 camera traps for 6 years in the SNNR, we calculated a relative abundance index (RAI) and pca for cougar and each of the focal prey, and we used the normalized difference vegetation index (NDVI) as a proxy of primary productivity. We constructed multiple regression models and selected the best linear models based on ranking the AIC values. Our analysis suggests that P. concolor pca is best explained by bottom-up control and intraspecific feedback . White-tailed deer and armadillo pca were both significantly affected by cougar abundance, indicating top-down control for these prey species, but NDVI was not retained in any of the models selected for prey pca. Our results indicate that both bottom-up and top-down control are involved in regulating this endangered food web in the SNNR, Mexico. [ABSTRACT FROM AUTHOR]

The objective of the present paper is to provide a holistic framework to delineate 'territories of opportunity' where agrarian communities can manage areas to enhance the conservation of large vertebrates. The study was conducted Mexico, which is sociologically, culturally and ecologically complex, similar to other 'megadiverse' countries. We conducted ensemble niche modeling of endangered top predators to define a set of large vertebrate species. Environmental attributes were used to perform three distance-based and two artificial intelligence-based algorithms. Socio-cultural attributes were included to depict agricultural communities with strong social government schemes and clear evidence of well-managed natural resources. Other socio-economic attributes such as land acquisition cost, human agglomeration and anthropogenic land use were included in the analysis. Scenarios were computed and displayed cartographically with the aid of a geographic information system. Results showed that the largest concentration of biodiversity converges on regions with large land cover persistence and high local governance, defined as potential willingness to engage in conservation actions. The cartographic areas identified overlapped with current Mexican protected areas in only 2.7% of the country. Thus, conservation law enforcement in most of the country seems to be ineffective. Here we show that, in a number of territories, agrarian communities that have coexisted for millennia with umbrella species can be regarded as allies in biodiversity conservation. Results are discussed in the light of their relevance for future niche modeling, environmental policy design and implications for climate change. [ABSTRACT FROM AUTHOR]

Human activities are affecting the distribution of species worldwide by causing fragmentation and isolation of populations. Isolation and fragmentation lead to populations with lower genetic variability and an increased chance of inbreeding and genetic drift, which results in a loss of biological fitness over time. Studies of the genetic structure of small and isolated populations are critically important for management and conservation decisions. Ambystoma rivulare is a micro-endemic Mexican mole salamander from central Mexico. It is found in the most ecologically disturbed region in Mexico, the Trans-Mexican Volcanic Belt. The goal of this study of the population genetics of the micro-endemic mole salamander was to provide information to be used as a basis for future research and conservation planning of this species and other species of the Ambystoma genus in Mexico. The structural analysis found two subpopulations, one for each river sampled, with no signs of admixture and very high levels of genetic differentiation. Medium to high levels of heterozygosity and few alleles and genotypes were observed. Evidence of an ancestral genetic bottleneck, low values of effective population size, small inbreeding coefficients, and low gene flow were also found. [ABSTRACT FROM AUTHOR]

Genealogical records of animals (studbook) are created to avoid reproduction between closely related individuals, which could cause inbreeding, particularly for such endangered species as the Panthera onca (Linnaeus, 1758). Jaguar is the largest felid in the Americas and is considered an important ecological key species. In Mexico, wild jaguar populations have been significantly reduced in recent decades, and population decline typically accompany decreases in genetic variation. There is no current census of captive jaguars in Mexico, and zoos do not follow a standardized protocol in breeding programs based on genetic studies. Here, we emphasise the importance of maintaining an adequate level of genetic variation and propose the implementation of standardised studbooks for jaguars in Mexico, mainly to avoid inbreeding. In addition, achieving the aims of studbook registration would provide a population genetic characterisation that could serve as a basis for ex situ conservation programmes. [ABSTRACT FROM AUTHOR]

It is necessary to determine genetic diversity of fragmented populations in highly modified landscapes to understand how populations respond to land-use change. This information will help guide future conservation and management strategies. We conducted a population genetic study on an endemic Mexican Dusky Rattlesnake ( Crotalus triseriatus) in a highly modified landscape near the Toluca metropolitan area, in order to provide crucial information for the conservation of this species. There was medium levels of genetic diversity, with a few alleles and genotypes. We identified three genetically differentiated clusters, likely as a result of different habitat cover type. We also found evidence of an ancestral genetic bottleneck and medium values of effective population size. Inbreeding coefficients were low and there was a moderate gene flow. Our results can be used as a basis for future research and C. triseriatus conservation efforts, particularly considering that the Trans-Mexican Volcanic Belt is heavily impacted by destructive land-use practices. [ABSTRACT FROM AUTHOR]

Small or isolated populations are highly susceptible to stochastic events. They are prone and vulnerable to random demographic or environmental fluctuations that could lead to extinction due to the loss of alleles through genetic drift and increased inbreeding. We studied Ambystoma leorae an endemic and critically threatened species. We analyzed the genetic diversity and structure, effective population size, presence of bottlenecks and inbreeding coefficient of 96 individuals based on nine microsatellite loci. We found high levels of genetic diversity expressed as heterozygosity (H = 0.804, H = 0.613, H = 0.626 and H = 0.622). The population presents few alleles (4-9 per locus) and genotypes (3-14 per locus) compared with other mole salamanders species. We identified three genetically differentiated subpopulations with a significant level of genetic structure (F = 0.021, R = 0.044 y D = 0.010, 95 % CI). We also detected a reduction signal in population size and evidence of a genetic bottleneck (M = 0.367). The effective population size is small (Ne = 45.2), but similar to another mole salamanders with restricted distributions or with recently fragmented habitat. The inbreeding coefficient levels detected are low (F = −0.619-0.102) as is gene flow. Despite, high levels of genetic diversity A. leorae is critically endangered because it is a small isolated population. [ABSTRACT FROM AUTHOR]

The article presents a study which evaluates the association between the spatial factors and management with the livestock predations by Puma concolor in Central Mexico. The study uses the linear regressions to identify the variables which are best predicted predation risk. Results show that the risk of injury to pumas is reduced by the predation selection for goats and the livestock vulnerability was increased by the lack of night shelter in relation to the nocturnal habitats of the animal.