Phylogeny of the Avian Family Ciconiidae (storks) Based on Cytochrome B Sequences and DNA-DNA Hybridization Distances

This study is a phylogenetic analysis of the avian family Ciconiidae, the storks, based on two molecular data sets: 1065 base pairs of sequence from the mitochondrial cytochrome b gene and a complete matrix of single-copy nuclear DNA-DNA hybridization distances. Sixteen of the nineteen stork species were included in the cytochrome b data matrix, and fifteen in the DNA-DNA hybridization matrix. Both matrices included outgroups from the families Cathartidae (New World vultures) and Threskiornithidae (ibises, spoonbills). Optimal trees based on the two data sets were congruent in those nodes with strong bootstrap support. In the best-fit tree based on DNA-DNA hybridization distances, nodes defining relationships among very recently diverged species had low bootstrap support, while nodes defining more distant relationships had strong bootstrap support. In the optimal trees based on the sequence data, nodes defining relationships among recently diverged species had strong bootstrap support, while nodes defining basal relationships in the family had weak support and were incongruent among analyses. A combinable-component consensus of the best-fit DNA-DNA hybridization tree and a consensus tree based on different analyses of the cytochrome b sequences provide the best estimate of relationships among stork species based on the two data sets.