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Because systematic studies based on morphology have failed to fully resolve phylogenetic relationships of shanks (Charadriiformes: Scolopacidae), we obtained mitochondrial DNA (6349 bp) and nuclear DNA (1315 bp) sequences from 15 taxa. Using maximum parsimony and Bayesian analysis we show that Catoptrophorus and Heteroscelus are embedded within Tringa, and thus these genera should be merged in Tringa. Phylogenetic analyses of 18 morphological characters resulted in a partly resolved tree, so we mapped them on the molecular phylogeny and reconstructed ancestral states by maximum likelihood. Twelve of the morphological characters are homoplastic or plesiomorphic, and only six are phylogenetically informative, placing Xenus and Actitis outside the remaining genera. The bright yellow and red leg coloration of yellowlegs and red shanks are, respectively, a retained ancestral state and a parallel acquisition. Using a semi-parametric penalized-likelihood approach to correct for rate variation among lineages we estimated that speciation occurred in the Early Miocene-Pliocene. [ABSTRACT FROM AUTHOR]

We employed Bayesian coalescent modeling of samples of mitochondrial control region sequences in two species of shorebird, Red Knots (Calidris canutus) and Dunlins (Calidris alpina) to estimate evolutionary effective population size, population divergence times, and time to most recent common ancestor of genes in the samples. The gene trees for the two species contrast sharply: knot haplotypes were connected in a shallow, star phylogeny whereas Dunlin haplotypes were related in a deeper bifurcating genealogy. Divergence times of populations representing all six subspecies of knots are estimated to have occurred within the last 20 000 (95% CI: 5600-58 000) years, and evolutionary effective population sizes of females are small (Nef = 2000-14 000). We hypothesized that breeding knots were restricted to unglaciated regions of Eurasia during the last glacial maximum, and gradually expanded eastwards into Alaska, the high Canadian Arctic and Greenland as the ice melted. Population divergence times in Dunlins are much older (58 000-194 000 ybp) and effective population size has historically been higher in major lineages (Nef 12 000-44 000). We conclude that Dunlin populations were not severely reduced in size in the last 200 000 years, and major lineages have differentiated under restricted gene flow for a much longer time than knots. Knots present a snapshot of genetic evolution in the last 20 000 years, whereas Dunlins display patterns of genetic evolution over an order of magnitude longer time frame. [ABSTRACT FROM AUTHOR]

The Resplendent Quetzal (Pharomachrus mocinno) is a threatened bird species classified into two putative subspecies (P. m. mocinno and P. m. costaricensis) and distributed in cloud forests of seven countries in Mesoamerica. Because the birds are rare, tissue samples are difficult to obtain, but we analyzed genetic diversity in 25 quetzals from five countries based on 255 bp of domain I of the control region of mitochondrial DNA. Eight haplotypes were detected. Nucleotide diversity for Mexico (P. m. mocinno: 0.0021) and Panama (P. m. costaricensis: 0.0026) were low, and did not differ from the values estimated for other birds species irrespective of whether they were endangered. A haplotype tree rooted with the Pavonine Quetzal (P. pavoninus) recovered two reciprocally monophyletic clades corresponding to each subspecies, so we propose that each subspecies be considered as an evolutionarily significant unit for conservation planning. A minimum spanning network showed the number of genetic differences separating haplotypes within subspecies was small relative to the number of substitutions among them, indicating strong population subdivision (FST = 0.37). In spite of the limited sampling we propose that in conservation practice Mexico-Guatemala, Nicaragua, El Salvador, and Panama be considered preliminarily as independent conservation management units since they each have unique haplotypes. Additionally, these countries should construct international agreements to protect the natural vegetation corridors among cloud forests of Mesoamerica and to curtail the illegal trade of quetzals. [ABSTRACT FROM AUTHOR]

Presents information on a study which examined molecular and phenotypic sexing in red knots. Employment of molecular sexing method; Quantification of the magnitude of sexual dimorphism in size; Results; Discussion.