Temporal and spatial variation of waterbirds at Sayula Lagoon, Jalisco, Mexico: a five–year winter season study

Variació temporal i espacial dels ocells aquàtics de la llacuna de Sayula, Jalisco, Mèxic: estudi de cinc temporades hivernals Els aiguamolls del centre de Mèxic són hàbitats importants tant per a ensambles d’ocells migratoris com residents. Per tal d’estudiar la variació quant a riquesa i abundància dels ocells aquàtics es van portar a terme observacions mensuals en 30 parcel·les permanents de tota la llacuna de Sayula, Jalisco, Mèxic, durant les temporades hivernals (d’octubre a març) dels anys 2004 a 2007 i 2009 a 2011. S’hi van registrar 73 espècies. Un total de 39 espècies són visitants invernals i vuit estan incloses en alguna categoria de risc. Les famílies més ben representades van ser: Anatidae, Scolopacidae i Ardeidae. Spatula clypeata i Anser caerulescens van ser les espècies més abundants. Es va observar una variació de la riquesa entre zones (només dues van ser similars), però no entre estacions (només WS4 va ser diferent) ni entre mesos (només el mes de novembre va ser diferent). La llacuna de Sayula és un ecosistema molt dinàmic influït per la migració i l’aportació d’aigua durant la temporada de pluges.Dades publicades a GBIF (doi: 10.15470/cuwqgi)Variación temporal y espacial de las aves acuáticas de la laguna de Sayula, Jalisco, México: estudio de cinco temporadas invernales Los humedales del centro de México son hábitats importantes para ensambles de aves tanto migratorias como residentes. A fin de estudiar la variación en cuanto a riqueza y abundancia de las aves acuáticas, se realizaron observaciones mensuales en 30 parcelas permanentes de toda la laguna de Sayula, Jalisco, México, durante las temporadas invernales (de octubre a marzo) de los años 2004 a 2007 y 2009 a 2011. Se registraron 73 especies. Un total de 39 especies son visitantes invernales y ocho están incluidas en alguna categoría de riesgo. Las familias mejor representadas fueron: Anatidae, Scolopacidae y Ardeidae. Spatula clypeata y Anser caerulescens fueron las especies más abundantes. Se observó variación de la riqueza entre zonas (sólo dos fueron similares), pero no entre estaciones (solo WS4 fue diferente) ni entre meses (solo el mes de noviembre fue diferente). La laguna de Sayula es un ecosistema muy dinámico influido por la migración y el aporte de agua durante la temporada de lluvias. Datos publicados en GBIF (doi: 10.15470/cuwqgi)Wetlands in central Mexico are important habitats for assemblages of migratory and resident birds. To study variation in richness and abundance of waterbirds, we conducted monthly observations in 30 permanent plots throughout the Sayula Lagoon, Jalisco, Mexico, during the winter season (from October to March) from 2004-2007 and from 2009-2011. Seventy-three species were recorded; 39 species were winter visitors, and eight species are included in some risk category. The best represented families were: Anatidae, Scolopacidae and Ardeidae. Spatula clypeata and Anser caerulescens were the most abundant species. We found variation in richness between zones (only two were similar), but not between the seasons (only WS4 was different) or months (only NOV was different). Sayula lagoon is a highly dynamic ecosystem influenced by migration and the water inputs occurring during the rainy season.Data published in GBIF (doi: 10.15470/cuwqgi

Efectos del uso del suelo en la sobrevivencia de nidos en pastizales abiertos en el sur del desierto chihuahuense

Las aves de pastizal de Norte América han sufrido tremendas disminuciones en sus poblaciones. Las causas de estos declives únicamente se conocen de manera parcial y existen varios factores que pueden estar involucrados, tales como la pérdida y degradación de pastizales, fragmentación de hábitats, efectos de borde, pastoreo, clima, estructura vegetal, y abundancia y patrones de actividad de depredadores de nidos. Estos efectos pueden variar entre regiones y a través del tiempo. Examinamos el efecto de tres tipos de uso del suelo del pastizal mediano abierto (pastizal abierto, pastizal tipo sabana con pastoreo, y agricultura) en la sobrevivencia de nidos de aves en los Llanos de Ojuelos, Jalisco, en la porción más meridional del desierto Chihuahuense. También examinamos hipótesis alternativas referentes a la estructura vegetal, exposición de nidos, temporalidad, y precipitación. Durante las épocas de anidación de 2004 y 2005 registramos información de sobrevivencia de 271 nidos de ocho especies para un total de 3,909 días de exposición en nueve sitios de estudio. Para el análisis estadístico de los datos utilizamos los métodos de exposición logística y criterio de información de Akaike, y concluimos que el tipo de uso de suelo tuvo la mayor influencia con una mayor sobrevivencia de nidos en pastizales abiertos y en pastizales tipo sabana que en los sitios agrícolas. La etapa de anidación también influyó en el éxito reproductivo con mayor sobrevivencia de nidos durante la incubación que en la etapa alimentación de polluelos en el nido. Sin embargo, los intervalos de confianza fueron bastante grandes, sugiriendo que estudios posteriores deben incorporar otro tipo de efectos, tales como fragmentación a diferentes escalas espaciales, efectos de borde, y regímenes de actividad de depredadores potenciales de los nidos

Presence of exotic birds in San Luis Potosi city, Mexican Plateau

We recorded 12 exotic bird species in San Luis Potosi, Mexico and adjacent areas. Obtained data were collected during the period August 2012 to August 2013. From the total of recorded species, eight are confirmations (Anas platyrhynchos domesticus, Cairina moschata, Bubulcus ibis, Columba livia, Sturnus vulgaris, Turdus rufopalliatus, Quiscalus mexicanus and Passer domesticus) and four are new records (Aratinga canicularis, Amazona oratrix, A. autumnalis and Cyanocorax yncas). Although not all exotic species represent a risk because of the lack of the necessary resources for the establishment of abundant viable populations, it is important to publicize their status in the region. Therefore, knowing the presence of exotic species in a new distribution area is important for monitoring its establishment and colonization, and defining management, control and eradication programs of these species, along with environmental education programs that would lead to a better understanding of impacts that these species can cause

Evaluating phyllostomid bat conservation potential of three forest types in the northern Neotropics of Eastern Mexico

Forest conversion to anthropogenic uses is a generalized phenomenon throughout tropical Latin America. We evaluated whether patches of secondary forest, which develop relatively rapidly after field abandonment, contribute to conservation of phyllostomid bat assemblages. Our objective was to compare patterns of phyllostomid bat abundance and the structure and composition of phyllostomid bat assemblages across three forest types in the northern neotropics of eastern Mexico. We studied phyllostomid bats within secondary evergreen, primary semi-deciduous, and primary evergreen forests. For each forest type, three representative sites were sampled with mist nets once during the dry season and once during the rainy season for a total of nine sites. Richness, diversity, and assemblage composition patterns were compared among forest types for all phyllostomid species, and for three groups of sensitivity to habitat fragmentation. Abundance of individual species was also compared among forest types. A total of 646 individual bats from 15 species, 11 of which were phyllostomids, were registered. Combining both seasons, more than 250 captures were accomplished at both the primary evergreen and secondary evergreen forests, and only 81 individuals were caught at primary semi-deciduous forests. Overall richness and diversity of species and sensitivity groups were greater in the rainy than the dry season. Richness was greater in secondary evergreen than in primary semi-deciduous forests, and diversity was greatest in the primary evergreen, intermediate in the secondary evergreen, and lowest in the primary semi-deciduous forest. Some overlap in composition was also evident, although there was separation between forest types and seasons. Mean abundances were higher for some species at primary evergreen and secondary evergreen forests, but were threefold lower (though not significantly) in secondary evergreen forests in the dry season for some other species. We also found that primary evergreen forests have the greatest importance for phyllostomids during the dry season. These results suggest that maintenance of secondary evergreen forests, which cover a large proportion of the northeastern Mexican neotropics, would contribute to the conservation of diverse tropical bat communities. Therefore, large areas of this forest type should necessarily be incorporated in the landscape

Seeds photoblastism and its relationship with some plant traits in 136 cacti taxa

Seed germination triggered by light exposure (positive photoblastism) has been determined in quantitative studies for numerous plant families and species. For Cactaceae, positive photoblastism is thought to be associated with life form and seed mass, but this association has never been evaluated. To explore hypotheses on associations between seed mass, seed dispersal, seed dormancy, life form, taxa and plant height with Relative Light Germination (RLG) in Cactaceae, we evaluated the effect of light on seed germination of 136 taxa. The taxa studied are native to several countries: México, Chile, Argentina, Brazil, Perú, USA, and Venezuela. Seed traits contrasted with RLG were life form, seed mass, seed dispersal, seed dormancy, adult plant height and taxon. We found some differences between RLG among taxa; Cacteae, Pachycereeae and Trichocereeae had higher RLG than Notocacteae. RLG was lower for seeds from taller than for shorter taxa, and lower for taxa with heavier seeds than for taxa with lighter seeds. Dispersal syndrome groups varied with RLG. RLG did not differ between cylindrical and globose taxa. Trends found here were in agreement with expectations for small-seeded species to have a light requirement to germinate more often than large-seeded species. This is the first time that cactus height is related to photoblastism. It is possible that seeds from tall plants are larger and thus have the capacity to produce taller seedlings than those from small plants, and that seedlings from large seeds with more resources have the ability to emerge from greater soil depths than those from small seeds.Fil: Flores, J.. Instituto Potosino de Investigación Científica y Tecnológica; MéxicoFil: Jurado, E.. Universidad Autónoma de Nuevo León; MéxicoFil: Chapa Vargas, L.. Instituto Potosino de Investigación Científica y Tecnológica; MéxicoFil: Ceroni Stuva, A.. Universidad Nacional Agraria La Molina; PerúFil: Dávila Aranda, P.. Universidad Nacional Autónoma de México; MéxicoFil: Galindez, Guadalupe. Instituto Nacional de Tecnología Agropecuaria. Centro Nacional de Investigaciones Agropecuarias. Centro de Investigación de Recursos Naturales. Instituto de Recursos Biológicos; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Gurvich, Diego Ezequiel. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: León Lobos, P.. Instituto de Investigaciones Agropecuarias; ChileFil: Ordóñez, C.. Universidad Nacional Autónoma de México; MéxicoFil: Ortega Baes, Francisco Pablo. Universidad Nacional de Salta. Facultad de Cs.naturales. Escuela de Agronomia. Laboratorio de Investigaciones Botanicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Salta; ArgentinaFil: Ramírez Bullón, N.. Universidad Nacional Agraria La Molina; PerúFil: Sandoval, A.. Instituto de Investigaciones Agropecuarias; ChileFil: Seal, C. E.. Royal Botanic Gardens; Reino UnidoFil: Ullian, T.. Royal Botanic Gardens; Reino UnidoFil: Pritchard, H. W.. Royal Botanic Gardens; Reino Unid

Ecophysiological and Anatomical Mechanisms behind the Nurse Effect: Which Are More Important? A Multivariate Approach for Cactus Seedlings

BACKGROUND: Cacti establish mostly occurs under the canopy of nurse plants which provide a less stressful micro-environment, although mechanisms underlying this process are unknown. The impact of the combination of light and watering treatments on Opuntia streptacantha (Cactaceae) seedlings was examined. METHODS/PRINCIPAL FINDINGS: Ecophysiological [titratable acidity, osmotic potential (‘solute potential’, Ψ(s)), relative growth rate (RGR) and their components (NAR, SLA, and LWR)], anatomical (chloroplast density, chloroplast frequency, and cell area), and environmental [photosynthetic photon flux density (PPFD) and air temperature] sets of variables were analyzed, assessing relationships between them and measuring the intensity of the relationships. Three harvests were carried out at days 15, 30, and 45. Ψ(s) and acidity content were the most important responses for seedling establishment. The main anatomical and environmental variables were chloroplast density and water availability, respectively. Opuntia streptacantha seedlings establish better in the shade-watering treatment, due to higher Ψ(s) and acidity, unaffected chloroplasts, and lower PPFD. In addition, the chloroplasts of cells under high-light and non-watering treatment were clumped closer to the center of the cytosol than those under shade-drought, to avoid photoinhibition and/or to better distribute or utilize the penetrating light in the green plant tissue. CONCLUSIONS: Opuntia seedlings grow better under the shade, although they can tolerate drought in open spaces by increasing and moving chloroplasts and avoiding drastic decreases in their Ψ(s). This tolerance could have important implications for predicting the impact of climate change on natural desert regeneration, as well as for planning reforestation-afforestation practices, and rural land uses