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1.
Mar Environ Res ; 186: 105926, 2023 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-36898302

RESUMEN

Identifying the areas of the world with suitable environmental conditions for the establishment of invasive species represents a fundamental basis for preventing their impacts. One of the most widely used tools for this is ecological niche modeling. Nonetheless, this approach may underestimate the specie's physiological tolerances (it's potential niche) since wildlife populations of species usually do not occupy their entire environmental tolerance. Recently, it has been suggested that incorporating occurrences of phylogenetically related species improves the prediction of biological invasions. However, the reproducibility of this technique remains unclear. Here, we evaluated the generality of this protocol by assessing whether the construction of modeling units above species level improves the capacity of niche models to predict the distribution of 26 target marine invasive species. For each, we constructed supraspecific modeling units based on published phylogenies by grouping the native occurrence records of each invasive species with the records of its phylogenetically closest relative. We also considered units at species level, including only the presence of records in the native areas of the target species. We generated ecological niche models for each unit with three modeling methods (minimum volume ellipsoids - MVE, machine learning algorithms - Maxent and a presence-absence method - GLM). In addition, we grouped the 26 target species based on whether or not the species are in environmental pseudo-equilibrium (i.e., it occupies all habitats where it can disperse) and have any geographical or biological constraints. Our results suggest that the construction of supraspecific units improves the predictive capacity of correlative models to estimate the invasion area of our target species. This modeling approach consistently generated models with a higher predictive ability for species in non-environmental pseudo-equilibrium and with geographical constraints.


Asunto(s)
Ecosistema , Especies Introducidas , Animales , Reproducibilidad de los Resultados , Modelos Teóricos , Animales Salvajes , Modelos Biológicos
2.
J Anim Ecol ; 92(4): 925-935, 2023 04.
Artículo en Inglés | MEDLINE | ID: mdl-36744653

RESUMEN

Climate temporality is a phenomenon that affects species activity and distribution patterns across spatial and temporal scales. Despite the global availability of microclimatic data, their use to predict activity patterns and distributions remains scarce, particularly at fine temporal scales (e.g. < month). Predicting activity patterns based on climatic data may allow us to foresee some of the consequences of climate change, particularly for ectothermic vertebrates. The Gila monster exhibits marked daily and seasonal activity patterns linked to physiology and reproduction. Here we evaluate whether ecological niche models fitted using microclimate data can predict temporal activity patterns using the Gila monster Heloderma suspectum as a study system. Furthermore, we identified whether the activity patterns are related to physiological constraints. We used dated occurrences from museum specimens and human observations to generate and test ecological niche models using minimum volume ellipsoids. We generated hourly microclimatic data for each occurrence site for 10 years using the NicheMapR package. For ecological niche modelling, we compared the traditional seasonal approach versus a daily activity pattern strategy for model construction. We tested both using the omission rate of independent observations (citizen science data). Finally, we tested whether unimodal and bimodal activity patterns for each season could be recreated through ecological niche modelling and whether these patterns followed known physiological constraints. The unimodal and bimodal activity patterns previously reported directly from tracking individuals across the year were recovered using niche modelling and microclimate across the species' geographical range. We found that upper thermal tolerances can explain the daily activity patterns of this species. We conclude that ecological niche models trained with microclimatic data can be used to predict activity patterns at high temporal resolutions, particularly on ectotherm species of arid zones coping with rapid climate modifications. Furthermore, the use of high temporal resolution variables can lead to a better niche delimitation, enhancing the results of any research objective that uses correlative models.


La estacionalidad climática es un fenómeno que afecta la actividad de las especies y los patrones de distribución a diferentes escalas espaciales y temporales. A pesar de la disponibilidad global de datos microclimáticos para estudiar dichos patrones, su uso sigue siendo escaso, particularmente en escalas temporales finas (e.g., < mes). La predicción de patrones de actividad basados en datos climáticos puede permitirnos prever algunas de las potenciales consecuencias del cambio climático, particularmente para los vertebrados ectotérmicos. El monstruo de Gila (Heloderma suspectum) exhibe marcados patrones de actividad diarios y estacionales vinculados a la fisiología y la reproducción. En este trabajo evaluamos cómo los modelos de nichos ecológicos ajustados con datos de microclima, pueden predecir patrones de actividad temporal, utilizando al monstruo de Gila como sistema de estudio. Además, identificamos si los patrones de actividad están relacionados con restricciones fisiológicas. Usamos registros de presencia provenientes de colecciones científicas y de ciencia ciudadana para generar y probar modelos de nichos ecológicos usando elipsoides de volumen mínimo. Generamos datos microclimáticos para cada hora en cada sitio de presencia durante diez años utilizando el paquete NicheMapR. Para el modelado de nichos ecológicos, comparamos el enfoque estacional tradicional con una estrategia de patrón de actividad diaria para la construcción del nicho. Ambos enfoques fueron probados utilizando la tasa de omisión de observaciones independientes (provenientes de datos de ciencia ciudadana). Finalmente, probamos si los patrones de actividad unimodales y bimodales para cada estación podían recrearse a través de modelos de nichos ecológicos y si estos patrones seguían restricciones fisiológicas conocidas. Los patrones de actividad unimodal y bimodal previamente informados directamente del seguimiento de individuos a lo largo del año, sí se recuperaron mediante el uso de modelos de nicho y microclimas en todo el rango geográfico de la especie. Encontramos también que las tolerancias térmicas superiores pueden explicar los patrones de actividad diaria de esta especie. Concluimos que los modelos de nichos ecológicos entrenados con datos microclimáticos pueden usarse para predecir patrones de actividad en altas resoluciones temporales, particularmente en especies ectotermas de zonas áridas que se enfrentan a modificaciones climáticas rápidas. Además, consideramos que el uso de variables con alta resolución temporal puede conducir a una mejor delimitación de nichos, mejorando los resultados de cualquier objetivo de investigación que utilice estos modelos correlativos.


Asunto(s)
Ecosistema , Microclima , Animales , Humanos , Vertebrados , Modelos Teóricos , Geografía
3.
Parasitology ; 149(8): 1129-1144, 2022 07.
Artículo en Inglés | MEDLINE | ID: mdl-35535473

RESUMEN

Long-term, inter-annual and seasonal variation in temperature and precipitation influence the distribution and prevalence of intraerythrocytic haemosporidian parasites. We characterized the climatic niche behind the prevalence of the three main haemosporidian genera (Haemoproteus, Plasmodium and Leucocytozoon) in central-eastern Mexico, to understand their main climate drivers. Then, we projected the influence of climate change over prevalence distribution in the region. Using the MaxEnt modelling algorithm, we assessed the relative contribution of bioclimatic predictor variables to identify those most influential to haemosporidian prevalence in different avian communities within the region. Two contrasting climate change scenarios for 2070 were used to create distribution models to explain spatial turnover in prevalence caused by climate change. We assigned our study sites into polygonal operational climatic units (OCUs) and used the general haemosporidian prevalence for each OCU to indirectly measure environmental suitability for these parasites. A high statistical association between global prevalence and the bioclimatic variables 'mean diurnal temperature range' and 'annual temperature range' was found. Climate change projections for 2070 showed a significant modification of the current distribution of suitable climate areas for haemosporidians in the study region.


Asunto(s)
Enfermedades de las Aves , Haemosporida , Parásitos , Plasmodium , Animales , Enfermedades de las Aves/epidemiología , Enfermedades de las Aves/parasitología , Cambio Climático , México/epidemiología , Filogenia , Prevalencia
4.
PLoS One ; 16(5): e0251027, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33956885

RESUMEN

Ecuador is one of the most biodiverse countries in the world, but faces severe pressures and threats to its natural ecosystems. Numerous species have declined and require to be objectively evaluated and quantified, as a step towards the development of conservation strategies. Herein, we present an updated National Red List Assessment for amphibian species of Ecuador, with one of the most detailed and complete coverages for any Ecuadorian taxonomic group to date. Based on standardized methodologies that integrate taxonomic work, spatial analyses, and ecological niche modeling, we assessed the extinction risk and identified the main threats for all Ecuadorian native amphibians (635 species), using the IUCN Red List Categories and Criteria. Our evaluation reveals that 57% (363 species) are categorized as Threatened, 12% (78 species) as Near Threatened, 4% (26 species) as Data Deficient, and 27% (168 species) as Least Concern. Our assessment almost doubles the number of threatened species in comparison with previous evaluations. In addition to habitat loss, the expansion of the agricultural/cattle raising frontier and other anthropogenic threats (roads, human settlements, and mining/oil activities) amplify the incidence of other pressures as relevant predictors of ecological integrity. Potential synergic effects with climate change and emergent diseases (apparently responsible for the sudden declines), had particular importance amongst the threats sustained by Ecuadorian amphibians. Most threatened species are distributed in montane forests and paramo habitats of the Andes, with nearly 10% of them occurring outside the National System of Protected Areas of the Ecuadorian government. Based on our results, we recommend the following actions: (i) An increase of the National System of Protected Areas to include threatened species. (ii) Supporting the ex/in-situ conservation programs to protect species considered like Critically Endangered and Endangered. (iii) Focalizing research efforts towards the description of new species, as well as species currently categorized as Data Deficient (DD) that may turn out to be threatened. The implementation of the described actions is challenging, but urgent, given the current conservation crisis faced by amphibians.


Asunto(s)
Anfibios , Especies en Peligro de Extinción , Animales , Anuros , Bufonidae , Conservación de los Recursos Naturales/métodos , Bases de Datos como Asunto , Ecosistema , Ecuador , Especies en Peligro de Extinción/estadística & datos numéricos
5.
Mol Phylogenet Evol ; 136: 29-34, 2019 07.
Artículo en Inglés | MEDLINE | ID: mdl-30930236

RESUMEN

Natural history collections are increasingly valued as genomic resources. Their specimens reflect the combined efforts of collectors and curators over hundreds of years. For many rare or endangered species, specimens are the only readily available source of DNA. We leveraged specimens from a historical collection to study the evolutionary history of wood-partridges in the genus Dendrortyx. The three Dendrortyx species are found in the highlands of central Mexico and Central America south to Costa Rica. One of these species is endangered, and in general, Dendrortyx are secretive and poorly represented in tissue collections. We extracted DNA from historical museum specimens and sequenced ultraconserved elements (UCEs) and mitochondrial DNA (mtDNA) to assess their phylogeny and divergence times. Phylogenies built from hundreds to thousands of nuclear markers were well resolved and largely congruent with an mtDNA phylogeny. The divergence times revealed an unusually old avian divergence across the Isthmus of Tehuantepec in the Pliocene around 3.6 million years ago. Combined with other recent studies, our results challenge the general pattern that highland bird divergences in Mesoamerica are relatively young and influenced by the Pleistocene glacial cycles compared to the older divergences of reptiles and plants, which are thought to overlap more with periods of mountain formation. We also found evidence for monophyletic genetic lineages in mountain ranges within the widespread D. macroura, which should be investigated further with integrative taxonomic methods. Our study demonstrates the power of museum genomics to provide insight into the evolutionary histories of groups where modern samples are lacking.


Asunto(s)
Ecosistema , Galliformes/genética , Especiación Genética , Genómica , Museos , Madera , Animales , Secuencia de Bases , Biodiversidad , América Central , ADN Mitocondrial/genética , Bosques , México , Filogenia , Filogeografía
6.
Zootaxa ; 4358(2): 271-294, 2017 Nov 29.
Artículo en Inglés | MEDLINE | ID: mdl-29245469

RESUMEN

In this study, we systematized available distribution data, obtained from biological databases and relevant literature, for Mexican species belonging to the tribe Phanaeini. The main objectives were to provide an overall description of the distribution records in biological collections, to detect potential sampling biases, to describe the seasonality of collections and to obtain species distribution models using the Desktop GARP algorithm. A total of 5,562 records, corresponding to 32 species in Mexico, were compiled, including the recently described Phanaeus zoque Moctezuma & Halffter, 2017. This compilation includes 784 unique collection records at 325 localities. These records were mainly distributed along the Trans-Mexican Volcanic Belt, the Sierra Madre Oriental and Sierra Madre Occidental mountain ranges and throughout the states of Chiapas and Veracruz. The Mexican High Plateau, the state of Tlaxcala and the Yucatan Peninsula are lacking in records. Distribution maps were created for species of three genera (Phanaeus MacLeay, 1819, Coprophanaeus Olsoufieff, 1924, and Sulcophanaeus Olsoufieff, 1924) and for 29 species present in Mexico. These species distributions are largely delimited by geomorphological features and vegetation types and coincide with expert descriptions of this tribe; some species show expanded distribution ranges. These maps provide a starting point for further analyses, the planning of future field studies, and the verification of possible new species in the Mexican territory.


Asunto(s)
Escarabajos , Animales , México
7.
PLoS One ; 12(9): e0183996, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-28863140

RESUMEN

In Mexico, the Long-tailed Wood-Partridge (Dendrortyx macroura) is distributed in the mountains of the Trans-Mexican Volcanic Belt, Sierra Madre del Sur and Sierra Norte de Oaxaca; while the Bearded Wood-Partridge (D. barbatus) is distributed in the Sierra Madre Oriental (SMO). There is a controversial overlap in distribution (sympatry) between these two species (on the Cofre de Perote and Pico de Orizaba volcanoes, SMO and Sierra Norte de Oaxaca), based on the ambiguity and current lack of information regarding the distribution of these two species. In order to disentangle the possible presence of both species in the area of sympatry, we conducted a crumble analysis of the historic knowledge regarding the geographic distribution of both species, based on a review of scientific literature, database records, the specimen examination (in ornithological collections), field work and a reconstruction of the distribution range based on Ecological Niche Modeling. Our results support the presence of only one of these two species in the overlapping area, rejecting the existence of such an area of sympatry between the two species. We discuss alternative hypotheses that could explain the historically reported distribution pattern: 1) an error in the single existing historical record; 2) a possible local extinction of the species and 3) the past existence of interspecific competition that has since been resolved under the principle of competitive exclusion. We propose that the Santo Domingo River in northern Oaxaca and western slope of the Sierra Madre Oriental, mark the distribution limits between these species.


Asunto(s)
Galliformes/clasificación , Variación Genética , Simpatría , Algoritmos , Animales , Biodiversidad , ADN Mitocondrial/genética , Sistemas de Información Geográfica , Geografía , México , Modelos Estadísticos , Filogenia , Curva ROC , Ríos , Programas Informáticos , Especificidad de la Especie
8.
Rev. biol. trop ; Rev. biol. trop;65(3): 1194-1207, Jul.-Sep. 2017. ilus
Artículo en Español | LILACS-Express | LILACS | ID: biblio-897614

RESUMEN

Resumen: El loro corona lila (Amazona finschi), es una especie endémica de las tierras bajas de la costa del Pacífico mexicano y está considerada en peligro. Sin embargo, ha sido documentado que la especie presenta migraciones estacionales y altitudinales a lo largo de su rango geográfico, lo que sugiere que su distribución ecológica y temporal permanece incierta. Se modeló la distribución potencial del loro corona lila considerando sus dos principales periodos de actividad: reproductiva y no reproductiva. Para desarrollar modelos de nicho ecológico, se usaron 428 presencias históricas de bases de datos de libre acceso en internet, que fueron combinados con cinco coberturas ambientales: tres climáticas y dos topográficas para cada periodo, mediante el algoritmo de Maxent. Posteriormente transferimos cada modelo estacional al resto de los meses para analizar si los movimientos estacionales de la especie estaban dirigidos por el clima. Se evaluaron las diferencias en las variables ecológicas entre estaciones mediante el uso de una prueba de "t". Analizamos mediante la superposición de los mapas, la correspondencia geográfica entre la distribución de loro y la de los recursos (plantas), usados por la especie. Se encontró una marcada estacionalidad en la distribución del loro corona lila. La especie presenta una mayor amplitud ecológica en términos de temperatura mínima durante la temporada reproductiva, pero una notable reducción en lo que se refiere a la precipitación. La distribución de los recursos de anidación y alimentación corresponde en gran medida con la distribución del loro corona lila. En el centro del rango de distribución de la especie existe un área donde se presentan las condiciones de las que la especie hace uso en ambas temporadas y en los periodos de transición entre estas. Finalmente, además de las implicaciones en la conservación de la especie, nuestros resultados acerca de la variación estacional en la distribución geográfica y ecológica del loro corona lila, son importantes para la comprensión de la distribución de otras especies, particularmente aquellas que se encuentran asociadas con ambientes altamente estacionales.


Abstract: The lilac-crowned parrot (Amazona finschi) is an endemic species restricted to lowlands of the Mexican Pacific coast and is currently considered as endangered. It has been documented that it shows altitudinal and seasonal migrations along its distributional range, suggesting that its ecological and temporal distribution is still uncertain. We modeled the potential distribution of the A. finschi considering the two main activity seasons for the species: reproductive and non-reproductive. We used 428 historical occurrences (1882-2014), obtained from open access databases, combined with five environmental layers: three climatic and two topographic for each season, to perform ecological niche models using Maxent. We then transferred each model to the rest of the months to analyze the seasonal movements guided by climate. Differences in ecological variables between seasons were evaluated using a t-test. The geographic correspondence among the parrot distribution and the resources (plants) distributions were analyzed by superimposing maps. A marked seasonality in the distribution of A. finschi was observed. Ecologically, the species displays greater amplitude during the breeding seasons in terms of minimum temperature, but a noticeable reduction as far as precipitation is concerned. The distribution of food and nesting resources largely corresponds to the distribution of this parrot. There is a wide area in the center of the geographical distribution in which the species finds conditions that meet both periods of activity, as well as transition conditions between these periods. Finally, our results on the seasonal variation in the geographical and ecological distribution of this species, possess a strong ecological meaning in the understanding of other species distribution, particularly those associated with highly seasonal environments, and definitively will contribute to the conservation of this species. Rev. Biol. Trop. 65 (3): 1194-1207. Epub 2017 September 01.

9.
PLoS One ; 11(3): e0150932, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-26968031

RESUMEN

We used Ecological Niche Modeling (ENM) of individual species of two taxonomic groups (plants and birds) in order to reconstruct the climatic distribution of Tropical Dry Forests (TDFs) in Mexico and to analyze their boundaries with other terrestrial ecosystems. The reconstruction for TDFs' distribution was analyzed considering the prediction and omission errors based upon the combination of species, obtained from the overlap of individual models (only plants, only birds, and all species combined). Two verifications were used: a primary vegetation map and 100 independent TDFs localities. We performed a Principal Component (PCA) and Discriminant Analysis (DA) to evaluate the variation in the environmental variables and ecological overlap among ecosystems. The modeling strategies showed differences in the ecological patterns and prediction areas, where the "all species combined" model (with a threshold of ≥10 species) was the best strategy to use in the TDFs reconstruction. We observed a concordance of 78% with the primary vegetation map and a prediction of 98% of independent locality records. Although PCA and DA tests explained 75.78% and 97.9% of variance observed, respectively, we observed an important overlap among the TDFs with other adjacent ecosystems, confirming the existence of transition zones among them. We successfully modeled the distribution of Mexican TDFs using a number of bioclimatic variables and co-distributed species. This autoecological niche approach suggests the necessity of rethinking the delimitations of ecosystems based on the recognition of transition zones among them in order to understand the real nature of communities and association patterns of species.


Asunto(s)
Aves/fisiología , Modelos Teóricos , Fenómenos Fisiológicos de las Plantas , Animales , Conservación de los Recursos Naturales/métodos , Bosques , México , Análisis de Componente Principal , Clima Tropical
10.
Glob Chang Biol ; 22(1): 364-79, 2016 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-26367278

RESUMEN

Assuming that co-distributed species are exposed to similar environmental conditions, ecological niche models (ENMs) of bird and plant species inhabiting tropical dry forests (TDFs) in Mexico were developed to evaluate future projections of their distribution for the years 2050 and 2070. We used ENM-based predictions and climatic data for two Global Climate Models, considering two Representative Concentration Pathway scenarios (RCP4.5/RCP8.5). We also evaluated the effects of habitat loss and the importance of the Mexican system of protected areas (PAs) on the projected models for a more detailed prediction of TDFs and to identify hot spots that require conservation actions. We identified four major distributional areas: the main one located along the Pacific Coast (from Sonora to Chiapas, including the Cape and Bajío regions, and the Balsas river basin), and three isolated areas: the Yucatán peninsula, central Veracruz, and southern Tamaulipas. When considering the effect of habitat loss, a significant reduction (~61%) of the TDFs predicted area occurred, whereas climate-change models suggested (in comparison with the present distribution model) an increase in area of 3.0-10.0% and 3.0-9.0% for 2050 and 2070, respectively. In future scenarios, TDFs will occupy areas above its current average elevational distribution that are outside of its present geographical range. Our findings show that TDFs may persist in Mexican territory until the middle of the XXI century; however, the challenges about long-term conservation are partially addressed (only 7% unaffected within the Mexican network of PAs) with the current Mexican PAs network. Based on our ENM approach, we suggest that a combination of models of species inhabiting present TDFs and taking into account change scenarios represent an invaluable tool to create new PAs and ecological corridors, as a response to the increasing levels of habitat destruction and the effects of climate change on this ecosystem.


Asunto(s)
Aves , Cambio Climático , Conservación de los Recursos Naturales/métodos , Bosques , Plantas , Animales , Ecosistema , México , Clima Tropical
11.
PLoS One ; 10(6): e0131452, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-26115482

RESUMEN

A widespread biogeographic pattern in nature is that population abundance is not uniform across the geographic range of species: most occurrence sites have relatively low numbers, whereas a few places contain orders of magnitude more individuals. The Bolson tortoise Gopherus flavomarginatus is endemic to a small region of the Chihuahuan Desert in Mexico, where habitat deterioration threatens this species with extinction. In this study we combined field burrows counts and the approach for modeling species abundance based on calculating the distance to the niche centroid to obtain range-wide abundance estimates. For the Bolson tortoise, we found a robust, negative relationship between observed burrows abundance and distance to the niche centroid, with a predictive capacity of 71%. Based on these results we identified four priority areas for the conservation of this microendemic and threatened tortoise. We conclude that this approach may be a useful approximation for identifying key areas for sampling and conservation efforts in elusive and rare species.


Asunto(s)
Conservación de los Recursos Naturales/métodos , Ecosistema , Modelos Teóricos , Tortugas , Animales , Demografía , México , Densidad de Población , Tortugas/crecimiento & desarrollo , Incertidumbre
12.
PLoS One ; 9(6): e100957, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-24963989

RESUMEN

BACKGROUND: Many authors have claimed that snakebite risk is associated with human population density, human activities, and snake behavior. Here we analyzed whether environmental suitability of vipers can be used as an indicator of snakebite risk. We tested several hypotheses to explain snakebite incidence, through the construction of models incorporating both environmental suitability and socioeconomic variables in Veracruz, Mexico. METHODOLOGY/PRINCIPAL FINDINGS: Ecological niche modeling (ENM) was used to estimate potential geographic and ecological distributions of nine viper species' in Veracruz. We calculated the distance to the species' niche centroid (DNC); this distance may be associated with a prediction of abundance. We found significant inverse relationships between snakebites and DNCs of common vipers (Crotalus simus and Bothrops asper), explaining respectively 15% and almost 35% of variation in snakebite incidence. Additionally, DNCs for these two vipers, in combination with marginalization of human populations, accounted for 76% of variation in incidence. CONCLUSIONS/SIGNIFICANCE: Our results suggest that niche modeling and niche-centroid distance approaches can be used to mapping distributions of environmental suitability for venomous snakes; combining this ecological information with socioeconomic factors may help with inferring potential risk areas for snakebites, since hospital data are often biased (especially when incidences are low).


Asunto(s)
Bothrops/fisiología , Ecosistema , Mapeo Geográfico , Actividades Humanas , Modelos Biológicos , Mordeduras de Serpientes/epidemiología , Animales , Salud Ambiental , Humanos , Incidencia , México/epidemiología , Prevalencia , Factores de Riesgo
13.
PLoS One ; 8(12): e81837, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-24339973

RESUMEN

We studied a population of the endangered glassfrog, Cochranella mache, at Bilsa Biological Station, northwestern Ecuador, from 2008 and 2009. We present information on annual abundance patterns, behavioral ecology, habitat use and a species distribution model performed with MaxEnt. We evaluate the importance of the National System of Protected Areas (SNAP) in Colombia and Ecuador, under scenarios of climate change and habitat loss. We predicted a restricted environmental suitability area from 48,509 Km(2) to 65,147 Km(2) along western Ecuador and adjacent Colombia; ∼ 8% of the potential distribution occurs within SNAP. We examined four aspects of C. mache ecology: (1) ecological data suggests a strong correlation between relative abundance and rainfall, with a high probability to observe frogs through rainy months (February-May); (2) habitat use and the species distribution model suggest that this canopy dweller is restricted to small streams and rivulets in primary and old secondary forest in evergreen lowland and piedmont forest of western Ecuador, with predictions of suitability areas in adjacent southern Colombia; (3) the SNAP of Colombia and Ecuador harbor a minimum portion of the predicted model of distribution (<10%); and (4) synergetic effects of habitat loss and climate change reduces in about 95% the suitability areas for this endangered frog along its distributional range in Protected Areas. The resulting model allows the recognition of areas to undertake conservation efforts and plan future field surveys, as well as forecasting regions with high probability of C. mache occurrence in western Ecuador and southern Colombia. Further research is required to assess population tendencies, habitat fragmentation and target survey zones to accelerate the discovery of unknown populations in unexplored areas with high probability of suitability. We recommend that Cochranella mache must be re-categorized as "Critically Endangered" species in national and global status, according with criteria and sub-criteria A4, B1ab(i,ii,iii,iv),E.


Asunto(s)
Anuros/fisiología , Ecosistema , Modelos Biológicos , Estaciones del Año , Clima Tropical , Animales , Colombia , Ecuador , Especies en Peligro de Extinción , Dinámica Poblacional
14.
Glob Chang Biol ; 19(8): 2524-35, 2013 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-23625760

RESUMEN

Climate change (CC) and sea level rise (SLR) are phenomena that could have severe impacts on the distribution of coastal dune vegetation. To explore this we modeled the climatic niches of six coastal dunes plant species that grow along the shoreline of the Gulf of Mexico and the Yucatan Peninsula, and projected climatic niches to future potential distributions based on two CC scenarios and SLR projections. Our analyses suggest that distribution of coastal plants will be severely limited, and more so in the case of local endemics (Chamaecrista chamaecristoides, Palafoxia lindenii, Cakile edentula). The possibilities of inland migration to the potential 'new shoreline' will be limited by human infrastructure and ecosystem alteration that will lead to a 'coastal squeeze' of the coastal habitats. Finally, we identified areas as future potential refuges for the six species in central Gulf of Mexico, and northern Yucatán Peninsula especially under CC and SLR scenarios.


Asunto(s)
Cambio Climático , Magnoliopsida/fisiología , Dispersión de las Plantas , Ecosistema , México , Modelos Biológicos
15.
Chiropt. neotrop. ; 17(2): 1017-1021, 2011.
Artículo en Español, Inglés | VETINDEX | ID: vti-464635

RESUMEN

Documentamos el primer registro de consumo y dispersión de semillas de Solanum schlechtendalianum (Solanaceae) por el murciélago de charreteras de tierras altas (Sturnira ludovici). La ingesta representó el 13%, 4% y el 80% del contenido total de su dieta en tres diferentes localidades estudiadas. Mediante experimentos de germinación in situ, determinamos un porcentaje de germinación de 30% de un total de 80 semillas digeridas; esto sugiere que S. ludovici actuá como dispersor legítimo de S. schlechtendalianum.


Consumption and seed dispersion of Solanum schlechtendalianum (Solanaceae) by the fruit bat Sturnira ludovici (Phyllostomidae). We presented the first report of the consumption and seed dispersion of Solanum schlechtendalianum (Solanaceae) by the highland yellow-shouldered bat (Sturnira ludovici). Intake accounted for 13%, 4% and 80% of total diet respectively in three studied locations. In situ germination experiments had a 30% of the 80 digested seeds; suggesting that S. ludovici is acting as legitimate seed disperser of S. schlechtendalianum.

16.
Chiropt. Neotrop. (Impr.) ; 17(2): 1017-1021, 2011.
Artículo en Español | LILACS-Express | VETINDEX | ID: biblio-1471968

RESUMEN

Documentamos el primer registro de consumo y dispersión de semillas de Solanum schlechtendalianum (Solanaceae) por el murciélago de charreteras de tierras altas (Sturnira ludovici). La ingesta representó el 13%, 4% y el 80% del contenido total de su dieta en tres diferentes localidades estudiadas. Mediante experimentos de germinación in situ, determinamos un porcentaje de germinación de 30% de un total de 80 semillas digeridas; esto sugiere que S. ludovici actuá como dispersor legítimo de S. schlechtendalianum.


Consumption and seed dispersion of Solanum schlechtendalianum (Solanaceae) by the fruit bat Sturnira ludovici (Phyllostomidae). We presented the first report of the consumption and seed dispersion of Solanum schlechtendalianum (Solanaceae) by the highland yellow-shouldered bat (Sturnira ludovici). Intake accounted for 13%, 4% and 80% of total diet respectively in three studied locations. In situ germination experiments had a 30% of the 80 digested seeds; suggesting that S. ludovici is acting as legitimate seed disperser of S. schlechtendalianum.

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