Author: LEONARDO CHAPA VARGAS
LEONARDO CHAPA VARGAS (2017)
"Raptor birds have widespread distributions in different environments throughout the planet. Yet, they are highly sensitive to landscape disturbances. We studied raptors in northern-central Mexico at the Highland plateau of San Luis Potosí and Zacatecas, in three landscape types that differed in proportion of agriculture. Our main goal was to determine whether small proportion of agriculture at the landscape level influences species richness, ecological diversity, and functional diversity. We conducted raptor road surveys during 1 year, from April 2015 to February 2016. We registered a total of 332 birds belonging to 14 diurnal raptor species. The most abundant species were Cathartes aura (turkey vulture), Falco sparverius (American kestrel), Caracara cheriway (crested caracara), and Buteo jamaicensis (red-tailed hawk). Three species: Aquila chrysaetos (golden eagle), Pandion haliaetus (osprey), and Falco columbarius (merlin) were exclusively recorded in the less-degraded, scrubland landscapes. However, no significant differences on average diversity were found between landscape types. Contrastingly, scrubland landscapes had the highest average functional diversity, followed by mixed landscapes, and then by agricultural landscapes, with significant differences in functional diversity between scrubland and agricultural landscapes. Overall, observed species richness in the study area formed four functional groups. These groups change and loose species as proportion of agriculture in the landscape progressively increases. The results suggested that the contribution of species richness to functional diversity, both for scrubland landscapes, which have the greatest functional diversity, and agricultural landscapes, which hold the smallest functional diversity, is important because there is substantial functional redundancy among landscape types."
"El rango de distribución restringido y el pequeño tamaño poblacional del gorrión de Worthen han ocasionado que esta ave sea considerada una especie amenazada en México y a nivel internacional. Aquí reportamos nuevos registros de esta ave los cuales expanden su rango de distribución conocido en los últimos cuarenta años y abren la posibilidad del uso de hábitats adicionales que no habían sido documentados anteriormente. Por lo tanto es importante realizar esfuerzos para documentar posible actividad reproductiva en estos hábitats."
"Se presenta el registro de 12 especies de aves exóticas para la ciudad de San Luis Potosí, México y áreas adyacentes. Los datos presentados se obtuvieron durante durante el periodo agosto de 2012 a agosto de 2013. Del total de especies registradas ocho son confirmaciones (Anas platyrhynchos domesticus, Cairina moschata, Bubulcus ibis, Columba livia, Sturnus vulgaris, Turdus rufopalliatus, Quiscalus mexicanus y Passer domesticus) y cuatro son nuevos registros (Aratinga canicularis, Amazona oratrix, A. autumnalis y Cyanocorax yncas). Aunque no todas las especies exóticas pueden representar un riesgo, debido a que no existen los recursos necesarios para el establecimiento de poblaciones abundantes viables, es importante dar a conocer su estatus en la región. Por lo que, el conocimiento de la presencia de especies exóticas es importante para dar seguimiento a su establecimiento y colonización en una nueva área, para así definir programas de manejo, control y erradicación para estas especies, aunado a programas de educación ambiental que conlleven a un mejor entendimiento sobre los impactos que estas pueden ocasionar."
"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."
"Reportamos dos observaciones visuales del ibis blanco (Eudocimus albus) de la Laguna de Los Coyotes, un afluente natural del manantial la Media Luna que se localiza en el municipio de Rioverde, San Luis Potosí, México. Los avistamientos ocurrieron en septiembre de 2011 y febrero de 2012. Este es el primer reporte de la presencia de esta ave en dicha localidad, y es importante porque la especie ha sido escasamente encontrada en ambientes no ribereños del Altiplano Mexicano."
"We report two visual records of the White Ibis (Eudocimus albus) at "Los Coyotes" lagoon, a natural affluent of the water spring "Media Luna" located at the "Rioverde" municipality of San Luis Potosi, Mexico. These visual encounters took place on September 2011 and February 2012. This is the first published report of the species at this locality, and our finding is important because this species has been barely found in non-coastal wetlands of the Mexican highland plateau."
"México alberga una diversidad biológica excepcional que lo coloca entre los principales países megadiversos, pues posee tres de las 34 ecorregiones del mundo y zonas consideradas áreas silvestres a nivel mundial, como los desiertos de Chihuahua, Sonora y California; su importancia radica en que reúne alrededor de 70 % de su hábitat original en buenas condiciones y una densidad poblacional humana menor a 5 habitantes km-2. El uso de la genómica como herramienta en la investigación científica en este país tuvo sus inicios a finales de 1930 con trabajos encaminados al mejoramiento genético de cultivos comerciales y a entender los fundamentos ecológicos de la variación genética en Drosophila pseudooscura, pero hasta los años 80 y 90 comenzó el estudio de la flora y la fauna bajo esa perspectiva. Sin embargo, a pesar del potencial que las técnicas genómicas ofrecen para mejorar el desarrollo de estrategias y políticas de gestión que aseguren la producción de alimentos y la preservación de especies, no han sido extensamente utilizadas. Se presenta una revisión de las áreas del conocimiento en la vida silvestre en las que la genómica ha sido incorporada para abordar poblaciones naturales y se discuten los aspectos en los que puede incidir dentro del manejo y conservación de taxa de importancia biológica y comercial."
"Mexico has a unique biodiversity that places it within the list of megadiverse countries; it has three of the 34 ecoregions of the world and sites that are considered wilderness areas worldwide. The use of Genomics as a tool for research in Mexico began in the late 1930s with work aimed at the genetic improvement of commercial crops and to understand the ecological foundations of the genetic variation in Drosohpila pseudooscura, however, it wasn't until the decades of 1980-1990s that these tools were used for the study of natural populations of flora and fauna with purposes of conservation and management. Nonetheless, the potential that genomic tools have to improve the strategies and policies of management to ensure food production and conservation of wildlife in Mexico, these have not been widely applied. In this paper the areas of knowledge in wildlife where genomics have been applied in the study of natural populations of flora and fauna in Mexico were reviewed, and the practical applications of genomics for management and conservation of species of biological and commercial concern were discussed."
"The Great kiskadee (Pitangus sulphuratus) has a continuous distribution in both slopes of Mexico, mainly in tropical zones. As a result of monthly samplings from December 2006 to August 2013, we report the occurrence of this species in eastern Aguascalientes and the Highland Plateau region of San Luis Potosi. Based on these records, we suggest that this species can be considered as a resident for this region, thus suggesting that its geographic distribution could be extended to the central plateau of Mexico."
"Avian haemosporidian parasites are particularly diverse and widespread. To date, more than 3,000 distinct cytochrome b lineages have been recorded, of which some present extremely wide geographical distributions, even including multiple continents. Whether these isolates represent one or several cryptic species remains unknown. Here we carried out a case study of SISKIN1, a common haemosporidian parasite lineage belonging to the morphologically described species Haemoproteus tartakovskyi. To shed light on its evolutionary origin, we investigated the divergence between SISKIN1 isolates obtained from siskins and redpolls in Europe (Russia and Sweden) and house finches in North America (Mexico). First, we used sequence capture of a small data set (2 Russian isolates and 1 Mexican isolate) to investigate the genetic structure based on the full-length mitochondrial genome and ?1,000 genes. The mitochondrial genomes of Russian isolates were identical with each other but differed from the Mexican one at 6 positions. The nuclear divergence between Russian and Mexican isolates was on average 2.8%, close to what has been observed between 2 species of malaria parasites that respectively infect humans (Plasmodium falciparum) and gorillas (Plasmodium praefalciparum). Second, we used the expanded data set (15 samples in total) to investigate the genetic structure in 3 genes known to be involved in host invasion. The European isolates were identical across all sequenced genes, whereas the Mexican isolates were highly diverse. The lack of shared alleles between European and Mexican populations suggests that they might have diverged in isolation without gene flow. From the MalAvi database we examined the lineages most similar to the SISKIN1 barcode fragment (part of the cyt b gene) and found that most of them had been recorded in North and South America. This suggests that the lineage SISKIN1 originated in North America and subsequently spread to Europe. Our analyses support that the cyt b gene barcoding region is a useful marker for identification of avian haemosporidian lineages that can classify them into clusters of closely related parasites, but to further investigate species limits and evolutionary history, molecular data from multiple faster-evolving genes are required."
Cytochrome b Lineage Evolutionary origin Genomic Divergence Geographical distribution Haemoproteus tartakovskyi Haemosporidian Parasites Haplotype network Nuclear genes Passerine Sequence Capture BIOLOGÍA Y QUÍMICA CIENCIAS DE LA VIDA BIOLOGÍA ANIMAL (ZOOLOGÍA) PARASITOLOGÍA ANIMAL PARASITOLOGÍA ANIMAL
"Dentro de las aves, las de pastizal son de las más amenazadas en el mundo. En México, estos ecosistemas se han visto afectados por el sobre-apacentamiento con ganado doméstico y la conversión a la agricultura. Para desarrollar planes de conservación es necesario evaluar las poblaciones y utilizar herramientas precisas que permitan conocer el estado de éstas. El objetivo del estudio fue comparar el conteo de aves por transecto y el puntual, para contrastar su efectividad al estimar la riqueza de especies y densidad de poblaciones, mediante cuatro diferentes distancias de detección en tres tipos de hábitats: pastizal mediano abierto, sabana y áreas agrícolas, las cuales diferían en su cubierta vegetal. La cuantificación se realizó en el periodo invierno-primavera 2004 - 2005. Las densidades más altas se obtuvieron con la técnica del conteo puntual en los intervalos de 0 - 25 y 25 - 50 m. El mayor número de especies se detectó con ambos métodos en las distancias de 0 a 75 m. Los resultados son consistentes para las dos estaciones y los tres hábitats, por lo que es posible combinar los métodos probados cuando se realicen inventarios referentes a la diversidad de aves de los pastizales semiáridos de México."
"Inside the birds group, the grassland birds are the most threatened in the world. In Mexico, these ecosystems have been affected by overgrazing by domestic livestock and conversion of soil to agriculture. To develop conservation plans is necessary to evaluate birds populations and the use of tools that help us to accurately assess the status of bird populations. The main objective of our study was to compare two bird-count methods (transect and point count), to contrast the effectiveness of estimating species richness and population densities at four detection distances in three contrasting grassland habitats: open middle grassland, savanna grassland and agriculture lands, these habitats differ in vegetation cover. Bird counts were conducted during winter 2004 and spring 2005. Estimated population densities were highest when using the PC method at distances of 0 - 25 m and 25 - 50 m. The greatest number of species was detected when both methods at distances of 0 to 75 m. These results were consistent for both seasons and for the three grassland habitats, in base to these results, combining both methods when realizing birds' diversity inventories in Mexican semiarid grasslands."
Studies of avian haemosporidians allow understanding how these parasites affect wild bird populations, and if their presence is related to factors such as habitat loss, degradation and fragmentation, and climate change. Considering the importance of the highland Plateau of Mexico as part of the North American bird migratory route and as a region containing important habitat for numerous bird species, the purpose of this study was to document haemosporidian species richness and how habitat degradation, bird body condition, and distance from water sources correlate with bird parasitemia.
We assessed the presence of avian haemosporidians in three resident bird species through microscopy and PCR amplification of a fragment of the haemosporidian cytochrome b gene. Average parasitemia was estimated in each species, and its relationship with habitat degradation through grazing, bird body condition and distance from water bodies was assessed.
High levels of parasitemia were recorded in two of the three bird species included in this study. Four lineages of haemosporidians were identified in the study area with nearly 50 % prevalence. Areas with highly degraded shrublands and villages showed higher parasitemia relative to areas with moderately degraded shrublands. No strong relationship between parasitemia and distance from water bodies was observed. There were no significant differences in prevalence and parasitemia between the two bird species infected with the parasites. Two of the sequences obtained from the fragments of the parasite's cytochrome b gene represent a lineage that had not been previously reported.
Haemosporidian diversity in arid zones of the Mexican highland plateau is high. Shrubland habitat degradation associated to the establishment of small villages, as well as tree extraction and overgrazing in the surroundings of these villages, significantly enhances parasitemia of birds by haemosporidians."
"Secondary forests are extensive in the tropics. Currently, these plant communities are the available habitats for wildlife and in the future they will possibly be some of the most wide-spread ecosystems world-wide. To understand the potential role of secondary forests for wildlife conservation, three ungulate species were studied: Mazama temama, Odocoileus virginianus and Pecari tajacu. We analyzed their relative abundance and habitat use at two spatial scales: (1) Local, where three different successional stages of tropical deciduous forest were compared, and (2) Landscape, where available habitats were compared in terms of landscape composition (proportion of forests, pastures and croplands within 113 ha). To determine the most important habitat-related environmental factors influencing the Sign Encounter Rate (SER) of the three ungulate species, 11 physical, anthropogenic and vegetation variables were simultaneously analyzed through model selection using Akaike’s Information Criterion. We found, that P. tajacu and O. virginianus mainly used early successional stages, while M. temama used all successional stages in similar proportions. The latter species, however, used early vegetation stages only when they were located in landscapes mainly covered by forest (97%). P. tajacu and O. virginianus also selected landscapes covered essentially by forests, although they required smaller percentages of forest (86%). All ungulate species avoided landscape fragments covered by pastures. For all three species, landscape composition and human activities were the variables that best explained SER. We concluded that landscape is the fundamental scale for ungulate management, and that secondary forests are potentially important landscape elements for ungulate conservation."
Conservation Huasteca Potosina Landscape composition Relative abundance Secondary tropical forest Ungulates BIOLOGÍA Y QUÍMICA CIENCIAS DE LA VIDA BIOLOGÍA VEGETAL (BOTÁNICA) ECOLOGÍA VEGETAL ECOLOGÍA VEGETAL