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1.
Environ Monit Assess ; 196(1): 89, 2023 Dec 26.
Article in English | MEDLINE | ID: mdl-38147172

ABSTRACT

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.


Subject(s)
Ursidae , Humans , Animals , Mexico , Environmental Monitoring , Area Under Curve
2.
PLoS Biol ; 21(1): e3001946, 2023 01.
Article in English | MEDLINE | ID: mdl-36719873

ABSTRACT

Large carnivores have long fascinated human societies and have profound influences on ecosystems. However, their conservation represents one of the greatest challenges of our time, particularly where attacks on humans occur. Where human recreational and/or livelihood activities overlap with large carnivore ranges, conflicts can become particularly serious. Two different scenarios are responsible for such overlap: In some regions of the world, increasing human populations lead to extended encroachment into large carnivore ranges, which are subject to increasing contraction, fragmentation, and degradation. In other regions, human and large carnivore populations are expanding, thus exacerbating conflicts, especially in those areas where these species were extirpated and are now returning. We thus face the problem of learning how to live with species that can pose serious threats to humans. We collected a total of 5,440 large carnivore (Felidae, Canidae, and Ursidae; 12 species) attacks worldwide between 1950 and 2019. The number of reported attacks increased over time, especially in lower-income countries. Most attacks (68%) resulted in human injuries, whereas 32% were fatal. Although attack scenarios varied greatly within and among species, as well as in different areas of the world, factors triggering large carnivore attacks on humans largely depend on the socioeconomic context, with people being at risk mainly during recreational activities in high-income countries and during livelihood activities in low-income countries. The specific combination of local socioeconomic and ecological factors is thus a risky mix triggering large carnivore attacks on humans, whose circumstances and frequencies cannot only be ascribed to the animal species. This also implies that effective measures to reduce large carnivore attacks must also consider the diverse local ecological and social contexts.


Subject(s)
Canidae , Carnivora , Ursidae , Animals , Humans , Ecosystem , Conservation of Natural Resources/methods
3.
Curr Biol ; 31(15): 3457-3466.e4, 2021 08 09.
Article in English | MEDLINE | ID: mdl-34237270

ABSTRACT

Large terrestrial carnivores have undergone some of the largest population declines and range reductions of any species, which is of concern as they can have large effects on ecosystem dynamics and function.1-4 The jaguar (Panthera onca) is the apex predator throughout the majority of the Neotropics; however, its distribution has been reduced by >50% and it survives in increasingly isolated populations.5 Consequently, the range-wide management of the jaguar depends upon maintaining core populations connected through multi-national, transboundary cooperation, which requires understanding the movement ecology and space use of jaguars throughout their range.6-8 Using GPS telemetry data for 111 jaguars from 13 ecoregions within the four biomes that constitute the majority of jaguar habitat, we examined the landscape-level environmental and anthropogenic factors related to jaguar home range size and movement parameters. Home range size decreased with increasing net productivity and forest cover and increased with increasing road density. Speed decreased with increasing forest cover with no sexual differences, while males had more directional movements, but tortuosity in movements was not related to any landscape factors. We demonstrated a synergistic relationship between landscape-scale environmental and anthropogenic factors and jaguars' spatial needs, which has applications to the conservation strategy for the species throughout the Neotropics. Using large-scale collaboration, we overcame limitations from small sample sizes typical in large carnivore research to provide a mechanism to evaluate habitat quality for jaguars and an inferential modeling framework adaptable to the conservation of other large terrestrial carnivores.


Subject(s)
Anthropogenic Effects , Motor Activity , Panthera , Spatial Behavior , Animals , Conservation of Natural Resources , Ecology , Ecosystem , Male
4.
Integr Zool ; 15(6): 471-481, 2020 Nov.
Article in English | MEDLINE | ID: mdl-32427390

ABSTRACT

During the last century, the coyote (Canis latrans) has increased its distribution in Central America. Before the 1980s, it had not been recorded in Panama. New records show that coyotes have crossed the Panama Canal, indicating that continues to expand; therefore, there is a possibility that it will reach northern South America. Our objectives were to identify potential coyote colonization routes to South America, and the variables that favor its expansion. We hypothesized that habitat fragmentation benefits coyote expansion. We applied 7 algorithms to model the potential distribution of the coyote, using 196 presence records and 12 variables. The models with better performance were used to generate a consensus model. Using our consensus model and the areas with highest probability of presence, a potential colonization route was generated between Central America and northern South America. This route lies through southern Costa Rica, along the Pacific coast of Panama to the south, to the Andean mountains in northern Colombia. The variables that explained potential coyote distribution were human population density, altitude, and percentage of crops with positive influence, and tropical broadleaf forests with negative influence. These results indicate that human activities and deforestation are related to coyote distribution expansion. Actions can be implemented within the identified route to improve environmental management, in order to avoid the presence of the coyote in the ecosystems of northern South America.


Subject(s)
Animal Distribution , Coyotes , Introduced Species , Algorithms , Altitude , Animals , Central America , Ecosystem , Homing Behavior , Humans , Population Density , South America
5.
Genetica ; 147(2): 149-164, 2019 Apr.
Article in English | MEDLINE | ID: mdl-30879155

ABSTRACT

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.


Subject(s)
Endangered Species , Polymorphism, Genetic , Urodela/genetics , Animals , Ecosystem , Microsatellite Repeats
6.
J Genet ; 97(5): 1119-1130, 2018 Dec.
Article in English | MEDLINE | ID: mdl-30555061

ABSTRACT

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 rattlesnakeswere 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.


Subject(s)
Crotalus/genetics , Gene Flow , Genetic Variation , Genetics, Population , Microsatellite Repeats , Population Density , Animals , Ecosystem , Gene Frequency , Mexico , Phylogeny
7.
Ecology ; 99(7): 1691, 2018 07.
Article in English | MEDLINE | ID: mdl-29961270

ABSTRACT

The field of movement ecology has rapidly grown during the last decade, with important advancements in tracking devices and analytical tools that have provided unprecedented insights into where, when, and why species move across a landscape. Although there has been an increasing emphasis on making animal movement data publicly available, there has also been a conspicuous dearth in the availability of such data on large carnivores. Globally, large predators are of conservation concern. However, due to their secretive behavior and low densities, obtaining movement data on apex predators is expensive and logistically challenging. Consequently, the relatively small sample sizes typical of large carnivore movement studies may limit insights into the ecology and behavior of these elusive predators. The aim of this initiative is to make available to the conservation-scientific community a dataset of 134,690 locations of jaguars (Panthera onca) collected from 117 individuals (54 males and 63 females) tracked by GPS technology. Individual jaguars were monitored in five different range countries representing a large portion of the species' distribution. This dataset may be used to answer a variety of ecological questions including but not limited to: improved models of connectivity from local to continental scales; the use of natural or human-modified landscapes by jaguars; movement behavior of jaguars in regions not represented in this dataset; intraspecific interactions; and predator-prey interactions. In making our dataset publicly available, we hope to motivate other research groups to do the same in the near future. Specifically, we aim to help inform a better understanding of jaguar movement ecology with applications towards effective decision making and maximizing long-term conservation efforts for this ecologically important species. There are no costs, copyright, or proprietary restrictions associated with this data set. When using this data set, please cite this article to recognize the effort involved in gathering and collating the data and the willingness of the authors to make it publicly available.


Subject(s)
Panthera , Animals , Ecology , Female , Humans , Male , Movement
8.
Integr Zool ; 13(1): 84-93, 2018 Jan.
Article in English | MEDLINE | ID: mdl-28261959

ABSTRACT

The study of predator-prey interactions is commonly analyzed using functional responses to gain an understanding of predation patterns and the impact they have on prey populations. Despite this, little is known about predator-prey systems with multiple prey species in sites near the equator. Here we studied the functional response of cougars (Puma concolor) in relation to their main prey, armadillo (Dasypus novemcinctus), coati (Nasua narica) and white-tailed deer (Odocoileus virginianus). Between 2004 and 2010, cougar scats were collected along 5 transects to estimate the consumption of different prey species. A relative abundance index (RAI) was calculated for each prey species and cougar using 18 camera traps. We compared Holling type I, II and III functional response models to determine patterns in prey consumption based on the relative abundance and biomass of each prey species consumed. The 3 main prey species comprised 55% (armadillo), 17% (coati) and 8% (white-tailed deer) of the diet. Type I and II functional responses described consumption of the 2 most common prey species armadillos and coati similarly well, while a type I response best characterized consumption of white-tailed deer. A negative correlation between the proportions of armadillo versus coati and white-tailed deer biomass in cougar scats suggests switching to consume alternative prey, confirming high foraging plasticity of this carnivore. This work represents one of the few studies to compare functional responses across multiple prey species, combined with evidence for prey-switching at low densities of preferred prey.


Subject(s)
Armadillos/physiology , Deer/physiology , Food Chain , Procyonidae/physiology , Puma/physiology , Animals , Feces , Predatory Behavior , Species Specificity
9.
Int. j. morphol ; 35(4): 1590-1596, Dec. 2017. graf
Article in English | LILACS | ID: biblio-893173

ABSTRACT

SUMMARY: Vertebrates exhibit structural changes in their cardiovascular and gas exchange systems in response to hypoxic conditions in high altitude environments. In highland neotenic mole salamanders, as other amphibians, the majority of gases exchange is carried out for skin and gills. But, in high altitude environments, the available oxygen is lower than it is in the air thus, the scarcity of oxygen limits the survival of organisms. Many studies on this subject have focused on understanding the hematological mechanisms that amphibians exhibit in response to hypoxia. However, little is known about possible morphological changes in respiratory structures that may permit increased gas exchange during respiration in high altitude amphibians like Ambystoma leorae and A. rivulare, two threatened Mexican salamander species. The aim of the present study was to describe and compare the histological characteristics of the gills and dorsal skin of A. leorae and A. rivulare from populations at low and high altitudes. We found that, in comparison to lowland organisms, highland ones exhibited more pronounced skin folds, greater numbers of secondary branches in the gills, thinner dorsal and gill epidermises, and greater quantity of melanin surrounding the gill blood vessels. These differences permit a greater capacity for gas exchange and also increase thermoregulatory capacity in high altitude environments.


RESUMEN: Los anfibios que viven en ambientes de altitud se enfrentan a factores abióticos que limitan la vida, tales como la disminución de la presión barométrica con la consecuente disminución de la presión parcial de oxígeno (O2). Conocer los mecanismos que optimizan la obtención del O2 en estos animales es de gran importancia para entender las diferencias en la sensibilidad a la hipoxia de las diferentes especies. Ambystoma rivulare y A. leorae son anfibios endémicos del Estado de México que viven en ambientes de alta altitud por lo que se cree presentan estrategias fenotípicas para asimilar eficazmente el O2 y poder subsistir en los ambientes de altitud. El objetivo de este trabajo fue analizar las características histológicas de branquias y piel cefálica (que son las principales estructuras que se encargan del intercambio gaseoso) provenientes de tres poblaciones con diferente altitud. Nuestros resultados muestran que los organismos que habitan a mayor altitud tienden a aumentar la superficie de intercambio gaseoso, como es el caso de pliegues epidérmicos y ramas branquiales secundarias. Las diferencias histológicas de branquias y piel cefálica tanto interespecíficas como intraespecíficas respecto a la altitud parecen apoyar la idea de que los organismos modifican sus estructuras para contrarrestar las limitantes de la vida en ambientes de altitud.


Subject(s)
Animals , Skin/anatomy & histology , Altitude , Ambystoma/anatomy & histology , Gills/anatomy & histology , Back
10.
J Genet ; 96(6): 873-883, 2017 Dec.
Article in English | MEDLINE | ID: mdl-29321345

ABSTRACT

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.


Subject(s)
Ambystomatidae/genetics , Genetic Variation , Genetics, Population , Animals , Ecosystem , Endangered Species , Gene Flow , Inbreeding , Mexico , Microsatellite Repeats/genetics , Population Density
11.
Genetica ; 144(6): 689-698, 2016 Dec.
Article in English | MEDLINE | ID: mdl-27796527

ABSTRACT

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.


Subject(s)
Ambystomatidae/genetics , Genetic Variation , Animals , Conservation of Natural Resources , Gene Flow , Mexico , Phylogeny , Population Density
12.
Dis Aquat Organ ; 121(2): 167-171, 2016 09 26.
Article in English | MEDLINE | ID: mdl-27667814

ABSTRACT

Ticks are common ectoparasites of amphibians and reptiles but very few reports of such parasites on crocodylians exist worldwide. Herein, we report the first detailed observations of Amblyomma dissimile Koch, 1844 on the 3 crocodylian species present in Mexico, with the first report of tick parasitism on Crocodylus acutus and the second on Caiman crocodilus chiapasius. This is also the first report of A. dissimile in the state of Quintana Roo. Proportions of infested individuals found in this study ranged from 0.51 to 1.96%, suggesting that tick parasitism in crocodylians is likely opportunistic and occurs when individuals leave the water for terrestrial activities. Tick parasitism does not represent a major threat to crocodylians. The increasing habitat destruction/fragmentation and cattle expansion in southeastern Mexico, however, could increase tick populations and trigger tick parasitism and tick-borne diseases in herpetofauna and other vertebrates, including humans. Thus, studies are needed to better understand these relationships.


Subject(s)
Alligators and Crocodiles/parasitology , Tick Infestations/veterinary , Animals , Ixodidae , Mexico/epidemiology , Tick Infestations/epidemiology
13.
Genetica ; 144(1): 59-69, 2016 Feb.
Article in English | MEDLINE | ID: mdl-26790662

ABSTRACT

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.


Subject(s)
Conservation of Natural Resources , Genetic Variation , Genetics, Population , Panthera/genetics , Animals , Animals, Zoo/genetics , Breeding , Genotype , Mexico , Pedigree , Population Density , Sequence Analysis, DNA
14.
Genetica ; 143(6): 705-16, 2015 Dec.
Article in English | MEDLINE | ID: mdl-26497875

ABSTRACT

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.


Subject(s)
Crotalus/genetics , Agriculture , Animals , Conservation of Natural Resources , Gene Flow , Genetic Variation , Inbreeding , Mexico , Population Density
15.
Zool Stud ; 54: e16, 2015.
Article in English | MEDLINE | ID: mdl-31966103

ABSTRACT

BACKGROUND: We evaluated the strategies of resources partitioning among species, dietary overlap and niche breadth in an assemblage of carnivores integrated by top predators (Puma concolor and Panthera onca) and mesopredators(Leoparduspardalis,Leoparduswiedii,Puma yagouaroundi,Nasuanarica andUrocyoncinereoargenteus). The aim of this study was to investigate the mechanisms explaining the coexistence among species at a temperate zone in central Mexico. RESULTS: We collected 259 scats of carnivores and identified 45 food items. The analysis showed the common consumptionof mammals in the assemblage, and the correspondence analysis showed three guilds: 1) top predators associated with the use of medium-sized mammals and the exclusive consumption of large mammals, 2) carnivore mesopredators associated with the consumption of small mammals and birds and 3) omnivore mesopredators associated with the consumption of arthropods and plants. The dietary overlap analysis indicated a low overlap between guilds and a high overlap within them. Top predators were specialist foragers, whilst the carnivore mesopredators showed generalist consumption. CONCLUSIONS: The coexistence in this carnivore assemblage seems to be related to body size, morphology and prey segregation because such characteristics suggest the presence of three guilds. We observed high dietary overlap within guilds and resource partitioning betweenguilds.

16.
PLoS One ; 9(7): e103595, 2014.
Article in English | MEDLINE | ID: mdl-25076052

ABSTRACT

The reduced immigration and emigration rates resulting from the lack of landscape connectivity of patches and the hospitality of the intervening matrix could favor the loss of alleles through genetic drift and an increased chance of inbreeding. In order for isolated populations to maintain sufficient levels of genetic diversity and adapt to environmental changes, one important conservation goal must be to preserve or reestablish connectivity among patches in a fragmented landscape. We studied the last known population of Ambystoma leorae, an endemic and critically threatened species. The aims of this study were: (1) to assess the demographic parameters of A. leorae and to distinguish and characterize the microhabitats in the river, (2) to determine the number of existing genetic groups or demes of A. leorae and to describe possible relationships between microhabitats types and demes, (3) to determine gene flow between demes, and (4) to search for geographic locations of genetic discontinuities that limit gene flow between demes. We found three types of microhabitats and three genetically differentiated subpopulations with a significant level of genetic structure. In addition, we found slight genetic barriers. Our results suggest that mole salamander's species are very sensitive to microhabitat features and relatively narrow obstacles in their path. The estimates of bidirectional gene flow are consistent with the pattern of a stepping stone model between demes, where migration occurs between adjacent demes, but there is low gene flow between distant demes. We can also conclude that there is a positive correlation between microhabitats and genetic structure in this population.


Subject(s)
Ambystoma/genetics , Alleles , Ambystomatidae , Animal Distribution , Animals , Cluster Analysis , Ecosystem , Endangered Species , Gene Flow , Genetic Drift , Genetic Variation , Inbreeding , Mexico , Microsatellite Repeats , Models, Genetic , Rivers
17.
Rev Biol Trop ; 61(1): 243-53, 2013 Mar.
Article in Spanish | MEDLINE | ID: mdl-23894977

ABSTRACT

White-tailed deer is a species with a large behavioral plasticity and adaptation to different habitats, including their food habits. This study was conducted with the aim to determine the food habits of this species in the cloud (BMM) and pine-oak (BPE) forests. Deer scats and plant samples were obtained following standard methods, from Sierra Nanchititla Park in the State of Mexico, from June 1990 to May 1992. A total of 104 deer pellet-groups were collected, and histological analysis for herbivores was used and compared with stock samples of plant tissues collected from the study area. We applied the Spearman correlation and Morisita index to determine alimentary preference. The results showed that the deer consumes 79.44% of plant species from BMM and 20.56% of the BPE. There is a selectivity tendency for 12 of the 14 plant species located in the BMM, while for BPE no tendency was observed. Key species that are part of the elemental diet of the deer in these areas were: Acalypha setosa, Smilax pringlei, Psidium sartorianum and Dendropanax arborea. The consumption of plants did not differ significantly between the dry and rainy seasons in terms of biological form, however, during the dry season there is a tendency to consume trees, and by the end of the rainy season to consume herbs. The data indicate that the deer can be selective with BMM plants, while for the BPE tends to be opportunistic.


Subject(s)
Conservation of Natural Resources , Deer/physiology , Feces/chemistry , Feeding Behavior/physiology , Animals , Deer/classification , Mexico , Seasons
18.
Rev. biol. trop ; 61(1): 243-253, Mar. 2013. ilus
Article in Spanish | LILACS | ID: lil-674076

ABSTRACT

Food habits of the white-tailed deer, Odocoileus virginianus (Artiodactyla: Cervidae) in Nanchititla Natural Park, Mexico. White-tailed deer is a species with a large behavioral plasticity and adapta- tion to different habitats, including their food habits. This study was conducted with the aim to determine the food habits of this species in the cloud (BMM) and pine-oak (BPE) forests. Deer scats and plant samples were obtained following standard methods, from Sierra Nanchititla Park in the State of Mexico, from June 1990 to May 1992. A total of 104 deer pellet-groups were collected, and histological analysis for herbivores was used and compared with stock samples of plant tissues collected from the study area. We applied the Spearman correlation and Morisita index to determine alimentary preference. The results showed that the deer consumes 79.44% of plant species from BMM and 20.56% of the BPE. There is a selectivity tendency for 12 of the 14 plant species located in the BMM, while for BPE no tendency was observed. Key species that are part of the elemental diet of the deer in these areas were: Acalypha setosa, Smilax pringlei, Psidium sartorianum and Dendropanax arborea. The consumption of plants did not differ significantly between the dry and rainy seasons in terms of biological form, however, during the dry season there is a tendency to consume trees, and by the end of the rainy season to consume herbs. The data indicate that the deer can be selective with BMM plants, while for the BPE tends to be opportunistic.


El venado cola blanca es una especie con una gran plasticidad conductual y de adaptación en diferentes hábitat. En el Parque Sierra Nanchititla en el Estado de México se realizó un estudio para determinar los hábitos alimentarios en el bosque mesófilo de montaña (BMM) y bosque de pino-encino (BPE). De junio 1990 a mayo 1992 se recolectaron 104 muestras de excremento de venado en las dos zonas de estudio. Aplicamos el índice de Morisita y la correlación de Spearman para determinar la preferencia alimentaria. Se utilizó el análisis histológico de heces fecales para herbívoros las cuales se compararon con muestras de tejidos vegetales de plantas de la zona de estudio. Los resultados muestran que consume el 79.44% de especies vegetales del BMM y 20.56% del BPE. Existe cierta tendencia en la selectividad de 12 de las 14 especies de plantas localizadas en el BMM, mientras que para el BPE no se aprecia tal tendencia. Las especies clave que for- man parte de la alimentación elemental del venado fueron: Acalypha setosa, Smilax pringlei, Psidium sartorianum y Dendropanax arborea. El consumo de plantas no varió sig- nificativamente entre la época seca y lluviosa en función de la forma biológica (X2=12, p=0.21). Sin embargo, durante la época seca existe cierta tendencia a consumir árboles y a finales de la época de lluvia a consumir hierbas (Z=1.61, p=0.95). Los datos indican que el venado puede ser selecti- vo con plantas del BMM, mientras que para el BPE tiende a ser oportunista.


Subject(s)
Animals , Conservation of Natural Resources , Deer/physiology , Feces/chemistry , Feeding Behavior/physiology , Deer/classification , Mexico , Seasons
19.
Rev Biol Trop ; 60(3): 1357-67, 2012 Sep.
Article in Spanish | MEDLINE | ID: mdl-23025104

ABSTRACT

Studies about the permanence of natural protected areas are important, because they contribute to the promotion of the conservation target and to optimize economical and human resources of specific areas. Although there are no natural protected areas in Guerrero, it has suitable habitat for the jaguar, a common species used for planning and management of conservation areas. Since, there is actual evidence that environmental and anthropogenic variables may modify vertebrate species distribution with time, in this study we predicted the potential distribution of Panthera onca using MaxEnt for this Southeastern region. In addition, we made a projection considering the effect of a moderate climate change scenario, to evaluate the stability of the conservation area for a period of 24 years. Furthermore, we applied three threat scenarios for the actual prediction to define conservation priorities areas. In our results, we have found that 18 361Km2 (29%) of this state has a permanent suitable habitat for jaguar conservation in the Sierra Madre del Sur and Pacific coast, with a possible loss of 2 000km2 in 24 years. This habitat is characterized by a 56% of temperate forest (mainly conifers and hardwoods 34%), and 35% of tropical deciduous forest. With the projections, the Southeastern region resulted with the higher anthropogenic impacts, while at the same time, an area of 7 900km2 in the Central-Western state was determined as a priority for conservation. To assure jaguar conservation, we propose the inclusion of this new conservation area, which is located in the Sierra Madre del Sur, with which we may potentially preserve other 250 species of threatened vertebrates. This way, the suggested habitat conservation may represent a local effort in Guerrero and will strengthen the biological corridor network for P. onca protection in Latin America.


Subject(s)
Ecosystem , Panthera/physiology , Animals , Conservation of Natural Resources , Demography , Mexico
20.
Rev. biol. trop ; 60(3): 1357-1367, Sept. 2012. mapas, tab
Article in Spanish | LILACS | ID: lil-659594

ABSTRACT

Studies about the permanence of natural protected areas are important, because they contribute to the promotion of the conservation target and to optimize economical and human resources of specific areas. Although there are no natural protected areas in Guerrero, it has suitable habitat for the jaguar, a common species used for planning and management of conservation areas. Since, there is actual evidence that environmental and anthropogenic variables may modify vertebrate species distribution with time, in this study we predicted the potential distribution of Panthera onca using MaxEnt for this Southeastern region. In addition, we made a projection considering the effect of a moderate climate change scenario, to evaluate the stability of the conservation area for a period of 24 years. Furthermore, we applied three threat scenarios for the actual prediction to define conservation priorities areas. In our results, we have found that 18 361Km2 (29%) of this state has a permanent suitable habitat for jaguar conservation in the Sierra Madre del Sur and Pacific coast, with a possible loss of 2 000km2 in 24 years. This habitat is characterized by a 56% of temperate forest (mainly conifers and hardwoods 34%), and 35% of tropical deciduous forest. With the projections, the Southeastern region resulted with the higher anthropogenic impacts, while at the same time, an area of 7 900km2 in the Central-Western state was determined as a priority for conservation. To assure jaguar conservation, we propose the inclusion of this new conservation area, which is located in the Sierra Madre del Sur, with which we may potentially preserve other 250 species of threatened vertebrates. This way, the suggested habitat conservation may represent a local effort in Guerrero and will strengthen the biological corridor network for P. onca protection in Latin America.


Guerrero se caracteriza por presentar extensiones considerables y adecuadas de hábitat para el jaguar, pero carece de áreas naturales protegidas. Son importantes los estudios sobre la persistencia de las áreas naturales protegidas debido a que ofrecen escenarios geográficos con mayor certidumbre de cumplir con el objetivo de la conservación biológica a largo plazo y con la optimización de recursos humanos y económicos. Existe evidencia de que variables ambientales y antropogénicas modifican la distribución de muchas especies de vertebrados, por lo que es necesario incluir estas variables como criterio en la selección de reservas. Se estimó la distribución potencial del jaguar utilizando MAxENT, misma que se uso como criterio para proponer áreas naturales protegidas en el Estado. Se realizó una proyección en el futuro para considerar el efecto de un escenario moderado de cambio climático y así poder proponer una zona de conservación que sea estable en un periodo de 24 años. También se aplicaron tres criterios de riesgo en la predicción actual para definir prioridades de conservación. Se determino que el 29% del estado es hábitat idóneo para el jaguar y será persistente en el futuro. Se propone al área ubicada en la Sierra Madre del Sur para la conservación de P. onca y potencialmente 250 especies de vertebrados amenazados ante la UICN. Conservar el hábitat de P. onca en Guerrero fortalecerá la red de corredores para la conservación del jaguar en Latinoamérica.


Subject(s)
Animals , Ecosystem , Panthera/physiology , Conservation of Natural Resources , Demography , Mexico
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