100 research outputs found
NUEVO REGISTRO DE CONEPATUS SEMISTRIATUS BODDAERT, 1784 (CARNIVORA: MUSTELIDAE) EN OAXACA, MÉXICO
Oaxaca is one of the most biodiverse regions in México harboring a high number of mammals species. In spite of the large number of mammal inventories conducted in this State, there are still many unexplored areas. We collected a specimen of the skunk Conepatus semistriatus outside of its known distribution range, located at La Fortaleza, Municipio de Santa Maria, Chimalapa. This new record pinpoints the need for continuing conducting biological inventories in regions holding a high biodiversity
Ecologic niche modeling and potential reservoirs for Chagas disease, Mexico
Centers for Disease Control and Prevention
http://www.cdc.gov/ncidod/EID/vol8no7/01-0454.htmEcologic niche modeling may improve our understanding of epidemiologically relevant vector and parasitereservoir
distributions. We used this tool to identify host relationships of Triatoma species implicated in
transmission of Chagas disease. Associations have been documented between the protracta complex (Triatoma:
Triatominae: Reduviidae) with packrat species (Neotoma spp.), providing an excellent case study
for the broader challenge of developing hypotheses of association. Species pairs that were identified coincided
exactly with those in previous studies, suggesting that local interactions between Triatoma and
Neotoma species and subspecies have implications at a geographic level. Nothing is known about sylvatic
associates of T. barberi, which are considered the primary Chagas vector in Mexico; its geographic distribution
coincided closely with that of N. mexicana, suggesting interaction. The presence of this species was
confirmed in two regions where it had been predicted but not previously collected. This approach may help
in identifying Chagas disease risk areas, planning vector-control strategies, and exploring parasite-reservoir
associations for other emerging diseases
PRIMER REGISTRO DEL TIGRILLO (LEOPARDUS WIEDII, SCHINZ 1821) Y DEL GATO MONTÉS (LYNX RUFUS, KERR 1792) EN LA RESERVA DE LA BIÓSFERA DE TEHUACÁN-CUICATLÁN, OAXACA, MÉXICO
Using camera-traps, two new records of margay (Leopardus wiedii) and two of lynx (Lynx rufus) were obtained at the Biosphere Reserve de Tehuacán-Cuicatlán, Oaxaca, Mexico, in 2003 and 2004. These are the first records documenting the presence of both species in this reserve
Phylogeny and Niche Conservatism in North and Central American Triatomine Bugs (Hemiptera: Reduviidae: Triatominae), Vectors of Chagas' Disease
The niche conservatism hypothesis states that related species diverge in niche characteristics at lower rates than expected, given their lineage divergence. Here we analyze whether niche conservatism is a common pattern among vector species (Hemiptera: Reduviidae: Triatominae) of Trypanosoma cruzi that inhabit North and Central America, a highly heterogeneous landmass in terms of environmental gradients. Mitochondrial and nuclear loci were used in a multi-locus phylogenetic framework to reconstruct phylogenetic relationships among species and estimate time of divergence of selected clades to draw biogeographic inferences. Then, we estimated similarity between the ecological niche of sister species and tested the niche conservatism hypothesis using our best estimate of phylogeny. Triatoma is not monophyletic. A primary clade with all North and Central American (NCA) triatomine species from the genera Triatoma, Dipetalogaster, and Panstrongylus, was consistently recovered. Nearctic species within the NCA clade (T. p. protracta, T. r. rubida) diverged during the Pliocene, whereas the Neotropical species (T. phyllosoma, T. longipennis, T. dimidiata complex) are estimated to have diverged more recently, during the Pleistocene. The hypothesis of niche conservatism could not be rejected for any of six sister species pairs. Niche similarity between sister species best fits a retention model. While this framework is used here to infer niche evolution, it has a direct impact on spatial vector dynamics driven by human population movements, expansion of transportation networks and climate change scenarios.CNIC was funded with a graduate scholarship from CONACYT (Consejo Nacional de Ciencia y Tecnologia) for his PhD studies in the Biomedical Sciences Program of the UNAM (Universidad Nacional Autonoma de Mexico), fulfilled in part by this study. Studies on vector bionomics and ecology were funded by CONACYT Fomix Morelos MOR-2004-C02-012 and CONACYT FONSEC 69997 and 161405 to JMR. This work was partially supported by DGAPA-UNAM (PAPIIT 487 IN225408, IN202711) and the CONACYT-CB-2009/132811 to VSC, and PAPIIT 2013488 and CONACYT-511 to AZR. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript
DISTRIBUCIÓN DE ROEDORES RESERVORIOS DEL VIRUS CAUSANTE DEL SÍNDROME PULMONAR POR HANTAVIRUS Y REGIONES DE POSIBLE RIESGO EN MÉXICO
We determined distributions of rodent species known as reservoirs of Sin Nombre virus, causal agent for the hantavirus pulmonary syndrome (HPS). In the absence of HPS cases reported in Mexico, this study aimed to identify potential risk regions for HPS based on distributions of these rodent reservoirs. We modeled species’ ecological niches and projected them as potential distributions using point occurrence data, environmental digital maps, the genetic algorithm GARP (Genetic Algorithm for Rule-set Prediction), and GIS. We determined potential distributions of three rodents known to serve as reservoirs for Sin Nombre virus, four additional rodent species that may also play a role, as well as all Peromsycus species, considered as potential reservoirs for Sin Nombre virus or other hantaviruses in Mexico. Geographic locations of HPS cases coincided significantly with modeled potential distributions of the three principal rodent reservoirs in the United States. In Mexico, distributions of rodent reservoirs and potential rodent reservoirs covered ample geographic regions. Rural human populations potentially exposed to HPS (living under marginal housing conditions and with a geographic coincidence with reservoir distributions), were estimated at 650,000 - 1,750,000 persons. The geographic coincidence between rodent reservoirs and HPS cases in the United States suggests that areas of high risk for HPS will be related to rodent reservoir distributions in Mexico. Since Mexico holds ecological and social conditions amply appropriate for HPS outbreaks, we predict that (1) HPS cases will be detected across broad geographic regions coinciding with rodent reservoir distributions in Mexico, and (2) HPS will prove to be more frequent in Mexico than in the United States.Se determinó la distribución geográfica de los roedores identificados como reservorios del virus Sin Nombre y otros posibles hantavirus en México, causante del síndrome pulmonar por hantavirus (SPH). Ante la ausencia de casos de SPH documentados en México, este estudio pretende identificar posibles regiones de riesgo, considerando la distribución geográfica de los roedores reservorios. Se modeló el nicho ecológico de las especies de roedores reservorios del virus, y se proyectó en mapas para estimar distribuciones potenciales, usando localidades de colecta, mapas ambientales digitales, el algoritmo genético de cómputo GARP (Genetic Algorithm for Rule-set Prediction, por sus siglas en inglés) y un sistema de información geográfico. Se incluyeron distribuciones potenciales de tres especies conocidas como reservorios importantes de hantavirus en Estados Unidos, cuatro especies de roedores que se consideran reservorios potenciales del virus en México y de todas las demás especies del género Peromyscus. Las localidades geográficas de los casos de SPH detectados en humanos en los Estados Unidos coincidieron de forma significativamente mayor que en un modelo al azar, con las distribuciones potenciales de los tres roedores reservorios. En México, los roedores reservorios y los roedores potencialmente reservorios, cubren extensas zonas geográficas, identificándose amplias regiones de posible riesgo de transmisión de hantavirus. La población potencialmente expuesta a la infección, considerando las características de vivienda rural y la distribución potencial de especies de roedores reservorios del virus, se estimó entre 650,000 y 1’750,000 personas. La coincidencia geográfica significativa entre la distribución de roedores reservorios con los casos de SPH reportados en los Estados Unidos, sugiere que la distribución de los roedores reservorios se correlaciona con áreas de riesgo de SPH. Ante la similitud entre México y las regiones de riesgo en los Estados Unidos respecto a sus condiciones biológicas, ecológicas y sociales propicias para la transmisión de SPH, predecimos que (1) en México se detectarán casos de SPH en amplias zonas geográficas, las cuales coinciden con las distribuciones de roedores reservorios y, (2) se va a registrar una mayor tasa de transmisión de SPH en México que en los Estados Unidos
Ecological Connectivity of Trypanosoma cruzi Reservoirs and Triatoma pallidipennis Hosts in an Anthropogenic Landscape with Endemic Chagas Disease
Traditional methods for Chagas disease prevention are targeted at domestic vector reduction, as well as control of transfusion and maternal-fetal transmission. Population connectivity of Trypanosoma cruzi-infected vectors and hosts, among sylvatic, ecotone and domestic habitats could jeopardize targeted efforts to reduce human exposure. This connectivity was evaluated in a Mexican community with reports of high vector infestation, human infection, and Chagas disease, surrounded by agricultural and natural areas. We surveyed bats, rodents, and triatomines in dry and rainy seasons in three adjacent habitats (domestic, ecotone, sylvatic), and measured T. cruzi prevalence, and host feeding sources of triatomines. Of 12 bat and 7 rodent species, no bat tested positive for T. cruzi, but all rodent species tested positive in at least one season or habitat. Highest T. cruzi infection prevalence was found in the rodents, Baiomys musculus and Neotoma mexicana. In general, parasite prevalence was not related to habitat or season, although the sylvatic habitat had higher infection prevalence than by chance, during the dry season. Wild and domestic mammals were identified as bloodmeals of T. pallidipennis, with 9% of individuals having mixed human (4.8% single human) and other mammal species in bloodmeals, especially in the dry season; these vectors tested >50% positive for T. cruzi. Overall, ecological connectivity is broad across this matrix, based on high rodent community similarity, vector and T. cruzi presence. Cost-effective T. cruzi, vector control strategies and Chagas disease transmission prevention will need to consider continuous potential for parasite movement over the entire landscape. This study provides clear evidence that these strategies will need to include reservoir/host species in at least ecotones, in addition to domestic habitats.This study was funded by the Secretaria de Salud and Consejo Nacional de Ciencia y Tecnología (CONACyt) project MOR-2004-CO2-012 to JMR, and by the Universidad Nacional Autónoma de México (PAPIIT project 225408 to VS-C, and the Sistema de Informática para la Biodiversidad y el Ambiente [SIBA], and Tecnologías para la Universidad de la Información y la Computación. AEGC was funded with a scholarship from CONACyT for a M. Sc. degree in vector-borne diseases at the Instituto Nacional de Salud Publica. CNIC is funded with a scholarship from CONACyT for studies at the graduate program in Biomedical Sciences of the Universidad Nacional Autonoma de Mexico
Current Knowledge of Leishmania Vectors in Mexico: How Geographic Distributions of Species Relate to Transmission Areas
This is the publisher's version, also available electronically at http://www.ajtmh.org/content/85/5/839Leishmaniases are a group of vector-borne diseases with different clinical manifestations caused by parasites transmitted by sand fly vectors. In Mexico, the sand fly Lutzomyia olmeca olmeca is the only vector proven to transmit the parasite Leishmania mexicana to humans, which causes leishmaniasis. Other vector species with potential medical importance have been obtained, but their geographic distributions and relation to transmission areas have never been assessed. We modeled the ecological niches of nine sand fly species and projected niches to estimate potential distributions by using known occurrences, environmental coverages, and the algorithms GARP and Maxent. All vector species were distributed in areas with known recurrent transmission, except for Lu. diabolica, which appeared to be related only to areas of occasional transmission in northern Mexico. The distribution of Lu. o. olmeca does not overlap with all reported cutaneous leishmaniasis cases, suggesting that Lu. cruciata and Lu. shannoni are likely also involved as primary vectors in those areas. Our study provides useful information of potential risk areas of leishmaniasis transmission in Mexico
Primer registro de la cojolita (Penelope purpurascens) en el estado de Guanajuato, México
-Aquí se informa sobre el registro de la cojolita en la Reserva de Biosfera Sierra Gorda de Guanajuato, el cual es el registro más central para esa latitud y el primero para el estado. Esta especie fue registrada fotográfícamente en un bosque de encino. La presencia de esta especie enfatiza la necesidad de continuar realizando inventarios biológicos en esta Reserva de la Biosfer
Factors affecting nectar sugar composition in chiropterophilic plants
AbstractMost pollinators prefer the sugars present in the nectar they consume, so it has been hypothesized that they have molded nectar trait evolution. However, nectar-feeding bats do not exhibit preferences for the sugars present in their diet. We analyzed the role that biochemical and ecological factors could play in shaping the nectar traits of chiropterophilic plants. We studied nectar traits and flower production in 49 plant species. We evaluated the relationship between nectar concentration and sugar composition using phylogenetically independent contrasts and if nectar traits were related to flower production using a Manova. We found that 42 species produced high hexoses nectars, and 7 species produced sucrose rich nectars. Phylogenetically independent contrasts showed that nectar concentration was negatively related to glucose content, positively related to fructose content, and was not related to sucrose content. A negative relationship was found from glucose and fructose contents to sucrose content, and glucose content was negatively related to fructose content. Finally, we did not found any relationship between nectar traits and the plants’ flowering strategies. We conclude that bat physiology and the relative low evolutionary time of the interaction between plants and bats may determine the lack of pattern in the nectar characteristics of chiropterophilic plants
Biotic predictors with phenological information improve range estimates for migrating monarch butterflies in Mexico
Although long-standing theory suggests that biotic variables are only relevant at local scales for explaining the patterns of species' distributions, recent studies have demonstrated improvements to species distribution models (SDMs) by incorporating predictor variables informed by biotic interactions. However, some key methodological questions remain, such as which kinds of interactions are permitted to include in these models, how to incorporate the effects of multiple interacting species, and how to account for interactions that may have a temporal dependence. We addressed these questions in an effort to model the distribution of the monarch butterfly Danaus plexippus during its fall migration (September-November) through Mexico, a region with new monitoring data and uncertain range limits even for this well-studied insect. We estimated species richness of selected nectar plants (Asclepias spp.) and roosting trees (various highland species) for use as biotic variables in our models. To account for flowering phenology, we additionally estimated nectar plant richness of flowering species per month. We evaluated three types of models: climatic variables only (abiotic), plant richness estimates only (biotic) and combined (abiotic and biotic). We selected models with AICc and additionally determined if they performed better than random on spatially withheld data. We found that the combined models accounting for phenology performed best for all three months, and better than random for discriminatory ability but not omission rate. These combined models also produced the most ecologically realistic spatial patterns, but the modeled response for nectar plant richness matched ecological predictions for November only. These results represent the first model-based monarch distributional estimates for the Mexican migration route and should provide foundations for future conservation work. More generally, the study demonstrates the potential benefits of using SDM-derived richness estimates and phenological information for biotic factors affecting species distributions.journal articl
- …