Birds of Sierra de Vallejo, Nayarit, Mexico

Sierra de Vallejo, is considered a priority region for conservation, and is strongly affected by anthropogenic pressures. The inventory of birds are refers to studies in near areas. This study is a concrete contribution of the birds of the mountain chain and north of it. We considered bibliographic records and databases available on the web with records of ocurrence and specimens of scientific collections. Also we perform point counts in different localities inside the reserve. We observed a richness of 261 birds species, the family Tyrannidae is the best represented. Of the species recorded, 177 are permanent residents (31 are endemic and 15 are quasi-endemics to Mexico) and 73 are migratory; the remaining eleven records have other status. Also 43 species are in endangered categories. We include species that have not been recorded in the lists of the area and records of species expand their ranges at Nayarit. Due to the great diversity of birds observed, it is necesary to continue the research work about habitat use, abundance and monitoring, it will provides the basis for the conservation of birds of Sierra de Vallejo

Diet and seed dispersal in two species of tanagers (Habia) from two types of vegetation in Los Tuxtlas, Ceracruz, Mexico

Fecal samples from mist-netted birds were used to determine the diet of the Red-throated (Habia fuscicauda) and Red-crowned (H. rubica) ant-tanagers in secondary vegetation and rainforest. The diet of both species is comprised mainly of various fruit species (65.9% and 66.6%) with animal prey making up a minor proportion (24.1% and 21.2%). Both species are considered dietary generalists and opportunists. In Los Tuxtlas, their diets are remarkably similar. The two species occur with equal frequency in the two types of studied vegetation and disperse seeds of several species of plant pioneers. These seeds are of great importance in the formation of seed banks that permit the development of secondary vegetation and, in the long run, the regeneration of the rainforest

Sexual dimorphism in Ivory-billed Woodcreepers (Xiphorhynchus flavigaster) in Mexico

We analyzed a sample of 173 specimens of different subspecies within the distribution of the Ivory-billed Woodcreeper (Xiphorhynchus flavigaster) in Mexico. Morphological variables were analyzed separately for males, females, juveniles, and adults. The results showed that males were larger in wing chord, tail length, body mass, and primary 8 length than females. Discriminant function analysis yielded correct classification as males or females in 95% of samples analyzed (92.3% of males and 100% of females). Additionally, we identified morphological variables which presented the highest correlation to obtain linear regression functions for estimating one or more missing variables in specimens. The discriminating function developed offers a means of determining the sex of individual Ivory-billed Woodcreepers, so this tool is valuable for ecological studies and population studies of this species

Speciation in the Emerald Toucanet (Aulacorhynchus prasinus) complex

We analyzed genetic variation in the Emerald Toucanet (Aulacorhynchus prasinus), a species complex that ranges primarily along the montane forests of southern and eastern Mexico south to Bolivia. Segments of three mitochondrial DNA genes (cytochrome b, ND2, and ND3) were sequenced for a total of 1,159 base pairs. Using maximum parsimony, maximum likelihood, and Bayesian analysis, we found a set of seven differentiated populations that correspond to clear geographic breaks throughout the highlands of the Neotropics. These genetically distinct populations also correspond with the geographic breaks found in previous analyses of morphological data. Molecular evidence suggests species treatment for four of the Central American clades and three South American clades