Underlying and proximate drivers of biodiversity changes in Mesoamerican biosphere reserves.

Protected areas are of paramount relevance to conserving wildlife and ecosystem contributions to people. Yet, their conservation success is increasingly threatened by human activities including habitat loss, climate change, pollution, and species overexploitation. Thus, understanding the underlying and proximate drivers of anthropogenic threats is urgently needed to improve protected areas' effectiveness, especially in the biodiversity-rich tropics. We addressed this issue by analyzing expert-provided data on long-term biodiversity change (last three decades) over 14 biosphere reserves from the Mesoamerican Biodiversity Hotspot. Using multivariate analyses and structural equation modeling, we tested the influence of major socioeconomic drivers (demographic, economic, and political factors), spatial indicators of human activities (agriculture expansion and road extension), and forest landscape modifications (forest loss and isolation) as drivers of biodiversity change. We uncovered a significant proliferation of disturbance-tolerant guilds and the loss or decline of disturbance-sensitive guilds within reserves causing a "winner and loser" species replacement over time. Guild change was directly related to forest spatial changes promoted by the expansion of agriculture and roads within reserves. High human population density and low nonfarming occupation were identified as the main underlying drivers of biodiversity change. Our findings suggest that to mitigate anthropogenic threats to biodiversity within biosphere reserves, fostering human population well-being via sustainable, nonfarming livelihood opportunities around reserves is imperative.

Riqueza y abundancia de aves en áreas verdes en la ciudad de San Cristóbal de las Casas, Chiapas, México / Richness and abundance of birds in green areas of San Cristobal de Las Casas city, Chiapas, Mexico

Resumen Las áreas verdes en las ciudades se han considerado elementos importantes para la conservación de la avifauna. En este estudio se presentan estimaciones de riqueza y abundancia de aves, así como su relación con las áreas verdes en la ciudad de San Cristóbal de Las Casas, Chiapas, México. Identificamos un total de 75 especies de aves en diez áreas verdes de diferente tamaño de febrero a julio de 2016 y relacionamos su presencia con variables ambientales a dos escalas geográficas (local y de paisaje). Se utilizaron análisis no paramétricos para comparar la riqueza y abundancia de las aves entre áreas verdes y categorías de tamaño. El porcentaje de superficie total ocupada por vegetación fue la variable más importante al correlacionarse positivamente con la riqueza y abundancia de las aves. Mientras que el porcentaje de cobertura de dosel, de construcciones, de pavimento y de áreas verdes muestreadas se correlacionaron negativamente con la riqueza y abundancia de aves. La heterogeneidad espacial de la estructura vegetal vertical en las áreas verdes fue importante para incrementar la diversidad de la avifauna. El mantenimiento e incremento de áreas verdes en ciudades es significativo para proteger y aumentar la diversidad de aves en áreas urbanas.

Abstract Green areas in urban districts are important elements for bird conservation. In this study, we estimated bird abundance within green areas in the urban district of San Cristobal de Las Casas, state of Chiapas, Mexico. We identified a total of 75 bird species in ten green areas of different sizes from February of 2016 through July of 2016. We related bird presence to environmental variables at two geographical scales (local and landscape). Nonparametric analyses were used to compare richness and abundance of birds between green areas and size categories. The percentage of vegetation area was the most important variable that positively correlated with species richness and abundance. However, negative correlations were found between species richness and abundance and the percentage coverage of canopy, buildings, pavement and sampled green areas. The spatial heterogeneity of vertical vegetation structure in green areas was important to increase the diversity of avifauna. The maintenance and increase of green areas in cities is important to protect and increase the diversity of birds in urban areas.

Organochlorine Pesticides in the Ferruginous Pygmy Owl (Glaucidium brasilianum) in Chiapas, Mexico.

Concentrations of organochlorine pesticides were quantified in samples of feathers (n = 17) and blood (n = 15) of the ferruginous pygmy owl (Glaucidium brasilianum). The individuals were captured near the Protected Natural Area Cerro Sonsonate, Chiapas, Mexico, between February and June 2014. In both tissues, pesticides belonging to seven organochlorine chemical families were detected. However, the organochlorine pesticide concentrations differed between feathers and blood. The highest concentrations of hexachlorocyclohexanes were found in feathers (0.63 ± 0.89 µg/g), whereas the highest concentrations of ΣDrines were found in blood (0.31 ± 0.47 µg/mL). By using the summed concentrations for each of the seven families of pesticides found in feathers, we did not find any significant correlation between the pesticides and pectoral muscle or body weight (p > 0.15). The ΣDDT group was the only pesticide family that showed a positive correlation with owl body weight (r = 0.60, p = 0.05); the concentrations of these pesticides were also high in feather and blood tissues (r = 0.87, p = 0.02). Our results confirm that ferruginous pygmy owls in the study area are exposed to these pesticides.

Cultural significance of wild mammals in Mayan and mestizo communities of the Lacandon Rainforest, Chiapas, Mexico.

BACKGROUND: Several ethnobiology studies evaluate the cultural significance (CS) of plants and mushrooms. However, this is not the case for mammals. It is important to make studies of CS allowing the comparison of cultural groups because the value given to groups of organisms may be based on different criteria. Such information would be valuable for wildlife preservation plans. In this study, the most culturally significant species of mammals from the Lacandon Rainforest (Chiapas, Mexico) for people from two Mayan-Lacandon and mestizo communities were identified. The reasons behind the CS of the studied species were explored and the existence of differences among the cultural groups was evaluated. METHODS: One hundred ninety-eight semi-structured and structured interviews were applied to compile socio-demographic information, qualitative data on CS categories, and free listings. Frequency of mention was a relative indicator to evaluate the CS of each species of mammal. Comparison of responses between communities was carried out through multivariate analyses. The non-parametric Mann-Whitney U test was used to compare the number of mentioned species by Lacandons and mestizos as well as different responses in the qualitative categories. A χ2 test was used to compare frequency of categories. RESULTS: 38 wild mammal species were identified. The classification and Principal Components Analyses show an apparent separation between Lacandon and mestizo sites based on the relative importance of species. All four communities mentioned the lowland paca the most, followed by peccary, white-tailed deer, armadillo, and jaguar. No significant difference was found in the number of mentioned species between the two groups. Eight CS categories were identified. The most important category was "harmful mammals", which included 28 species. Other relevant categories were edible, medicinal, and appearing in narratives. CONCLUSIONS: The data obtained in this study demonstrates the existence of differential cultural patterns in the relationships that Lacandon and mestizo groups establish with mammals. Species are deemed important either because they are eaten of because of the harm they cause. We suggest the incorporation of local conceptions about wild animals in conservation frameworks for the fauna in the Lacandon Rainforest.

CracidMex1: a comprehensive database of global occurrences of cracids (Aves, Galliformes) with distribution in Mexico.

Cracids are among the most vulnerable groups of Neotropical birds. Almost half of the species of this family are included in a conservation risk category. Twelve taxa occur in Mexico, six of which are considered at risk at national level and two are globally endangered. Therefore, it is imperative that high quality, comprehensive, and high-resolution spatial data on the occurrence of these taxa are made available as a valuable tool in the process of defining appropriate management strategies for conservation at a local and global level. We constructed the CracidMex1 database by collating global records of all cracid taxa that occur in Mexico from available electronic databases, museum specimens, publications, "grey literature", and unpublished records. We generated a database with 23,896 clean, validated, and standardized geographic records. Database quality control was an iterative process that commenced with the consolidation and elimination of duplicate records, followed by the geo-referencing of records when necessary, and their taxonomic and geographic validation using GIS tools and expert knowledge. We followed the geo-referencing protocol proposed by the Mexican National Commission for the Use and Conservation of Biodiversity. We could not estimate the geographic coordinates of 981 records due to inconsistencies or lack of sufficient information in the description of the locality. Given that current records for most of the taxa have some degree of distributional bias, with redundancies at different spatial scales, the CracidMex1 database has allowed us to detect areas where more sampling effort is required to have a better representation of the global spatial occurrence of these cracids. We also found that particular attention needs to be given to taxa identification in those areas where congeners or conspecifics co-occur in order to avoid taxonomic uncertainty. The construction of the CracidMex1 database represents the first comprehensive research effort to compile current, available global geographic records for a group of cracids. The database can now be improved by continuous revision and addition of new records. The CracidMex1 database will provide high quality input data that could be used to generate species distribution models, to assess temporal changes in species distributions, to identify priority areas for research and conservation, and in the definition of management strategies for this bird group. This compilation exercise could be replicated for other cracid groups or regions to attain a better knowledge of the global occurrences of the species in this vulnerable bird family.

Abundancia de colibríes y uso de flores en un bosque templado del sureste de México / Hummingbird abundance and flowers use in a template forest from Southeast Mexico

Hummingbird abundance varies with plant bloom phenology used for feeding. However, the information on hummingbird-flower interaction is limited for tropical mountain environments. We evaluated hummingbird abundance using mist nest and estimated monthly flowering phenology visited by hummingbirds in three different habitats (oak forest, cloud forest and bush) from January to August 2010 in Huitepec Ecological Reserve. We recorded four hummingbird species (Hylocharis leucotis, Lampornis amethystinus, Lamprolaima rhami and Eugenes fulgens), and their abundance varied among habitats (H3.8=14.8, p=0.001). Seven plant species were visited for hummingbirds and showed the highest number of flower species during dry season. Bush had the highest blossom. Fuchsia paniculata had the highest blossom period but only was visited by H. leucotis. Passiflora membranacea was the only species visited for all hummingbird species. The only positive association was E. fulgens abundance with P.a membranacea bloom (rS=0.93, p=0.02). Hummingbird abundance fluctuations in this study are determined for interactions with floral resources and their habitat distribution.

La abundancia de los colibríes puede variar por la fenología de floración de las plantas de las que se alimentan. Sin embargo, la información sobre la interacción colibrí-flor es limitada en ambientes tropicales de montaña. En este estudio se evaluó la abundancia de colibríes con redes de niebla y se registró la fenología de floración mensual de las flores visitadas por los colibríes en tres ambientes (bosque de encino, de neblina y matorral) en la Reserva Ecológica Huitepec, Chiapas, México de enero a agosto 2010. Cuatro especies de colibríes (Hylocharis leucotis, Lampornis amethystinus, Lamprolaima rhami y Eugenes fulgens) se registraron y sus abundancias variaron entre ambientes (H3.8=14.8, p=0.001). Siete especies de plantas fueron visitadas por los colibríes, y presentaron una mayor floración formando parches durante la temporada de secas. En el matorral se concentró el mayor número de especies de plantas con flores. Fuchsia paniculata presentó el mayor periodo de floración aunque solo fue visitada por H. leucotis. Passiflora membranacea fue la única especie visitada por las cuatro especies de colibríes. La única asociación positiva fue la abundancia de E. fulgens con la floración de P. membranacea (rS=0.93, p=0.02). Las fluctuaciones de las abundancias de colibríes en este estudio están en cierta forma determinadas por las interacciones del recurso floral y su distribución en el ambiente.

[Hummingbird abundance and flowers use in a template forest from Southeast Mexico]. / Abundancia de colibríes y uso de flores en un bosque templado del sureste de México.

Hummingbird abundance varies with plant bloom phenology used for feeding. However, the information on hummingbird-flower interaction is limited for tropical mountain environments. We evaluated hummingbird abundance using mist nest and estimated monthly flowering phenology visited by hummingbirds in three different habitats (oak forest, cloud forest and bush) from January to August 2010 in Huitepec Ecological Reserve. We recorded four hummingbird species (Hylocharis leucotis, Lampornis amethystinus, Lamprolaima rhami and Eugenes fulgens), and their abundance varied among habitats (H3.8=14.8, p=0.001). Seven plant species were visited for hummingbirds and showed the highest number of flower species during dry season. Bush had the highest blossom. Fuchsia paniculata had the highest blossom period but only was visited by H. leucotis. Passiflora membranacea was the only species visited for all hummingbird species. The only positive association was E. fulgens abundance with P.a membranacea bloom (r(S)=0.93, p=0.02). Hummingbird abundance fluctuations in this study are determined for interactions with floral resources and their habitat distribution.

Insights into the interaction of human arginase II with substrate and manganese ions by site-directed mutagenesis and kinetic studies. Alteration of substrate specificity by replacement of Asn149 with Asp.

To examine the interaction of human arginase II (EC 3.5.3.1) with substrate and manganese ions, the His120Asn, His145Asn and Asn149Asp mutations were introduced separately. About 53% and 95% of wild-type arginase activity were expressed by fully manganese activated species of the His120Asn and His145Asn variants, respectively. The K(m) for arginine (1.4-1.6 mM) was not altered and the wild-type and mutant enzymes were essentially inactive on agmatine. In contrast, the Asn149Asp mutant expressed almost undetectable activity on arginine, but significant activity on agmatine. The agmatinase activity of Asn149Asp (K(m) = 2.5 +/- 0.2 mM) was markedly resistant to inhibition by arginine. After dialysis against EDTA, the His120Asn variant was totally inactive in the absence of added Mn(2+) and contained < 0.1 Mn(2+).subunit(-1), whereas wild-type and His145Asn enzymes were half active and contained 1.1 +/- 0.1 Mn(2+).subunit(-1) and 1.3 +/- 0.1 Mn(2+).subunit(-1), respectively. Manganese reactivation of metal-free to half active species followed hyperbolic kinetics with K(d) of 1.8 +/- 0.2 x 10(-8) M for the wild-type and His145Asn enzymes and 16.2 +/- 0.5 x 10(-8) m for the His120Asn variant. Upon mutation, the chromatographic behavior, tryptophan fluorescence properties (lambda(max) = 338-339 nm) and sensitivity to thermal inactivation were not altered. The Asn149-->Asp mutation is proposed to generate a conformational change responsible for the altered substrate specificity of arginase II. We also conclude that, in contrast with arginase I, Mn(2+) (A) is the more tightly bound metal ion in arginase II.

Kinetic studies and site-directed mutagenesis of Escherichia coli agmatinase. A role for Glu274 in binding and correct positioning of the substrate guanidinium group.

The interaction of Escherichia coli agmatinase (EC 3.5.3.11) with the substrate guanidinium group was investigated by kinetic and site-directed mutagenesis studies. Putrescine and guanidinium ions (Gdn+) were slope-linear, competitive inhibitors with respect to agmatine and their bindings to the enzyme were not mutually exclusive. By site-directed mutagenesis, the E274A variant exhibiting about 1-2% of wild-type activity was obtained. Mutation produced a moderate, but significant, increase in the Km value for agmatine (from 1.1 +/- 0.2 mM to 6.3 +/- 0.3 mM) and the Ki value for competitive inhibition by Gdn+ (from 15.0 +/- 0.1 mM to 44.2 +/- 2.1 mM), but the Ki value for putrescine inhibition (2.8 +/- 0.2 mM) was not altered. The tryptophan fluorescence properties (lambdamax = 342 nm) and circular dichroism spectra were not significantly altered by the Glu274 --> Ala mutation. The dimeric structure of the enzyme was also maintained. We conclude that Glu274 is involved in binding and positioning of the guanidinium moiety of the substrate for efficient catalysis. A kinetic mechanism involving rapid equilibrium random release of products is proposed for E. coli agmatinase.