Abstract:
The monophyly and phylogeny of the adaptive radiation of Hawaiian finches (Fringillidae: Drepanidini; honeycreepers,
auct.) were studied using parsimony analysis of comparative osteology, combined with Templeton (Wilcoxon
signed-ranks) tests of alternative phylogenetic hypotheses. Eighty-four osteological characters were scored in 59 terminal
taxa of drepanidines, including 24 fossil forms, and in 30 outgroup species. The optimal phylogenetic trees
show considerable agreement, and some conflict, with independently derived ideas about drepanidine evolution. The
monophyly of a large Hawaiian radiation was upheld, although one fossil taxon from Maui fell outside the drepanidine
clade. The finch-billed species were placed as basal drepanidine taxa, and continental cardueline finches (Carduelini)
were identified as the radiation’s closest outgroups. The study found anatomical as well as phylogenetic
evidence that the radiation had a finch-billed ancestor. The optimal trees identify the red-and-black plumage group
as a clade, and suggest that the tubular tongue evolved only once in the radiation. Because comparative osteology
provides too few characters to strongly support all the nodes of the tree, it was helpful to evaluate statistical support
for alternative hypotheses about drepanidine relationships using the Templeton test. Among the alternatives that
received significant statistical support are a relationship of the drepanidines with cardueline finches rather than
with the Neotropical honeycreepers (Thraupini), classification of the controversial genera Paroreomyza and Melamprosops
as drepanidines, and a secondary loss of the tubular tongue in Loxops mana. The hypothesis of monophyly
for all the Hawaiian taxa in the study was not rejected statistically. The study provides a framework for incorporating
morphological and palaeontological information in evolutionary studies of the Drepanidini.