DNA sequences spanning 1,042 nucleotide bases of the mitochondrial cyt
ochrome-b gene are reported for all 15 species and selected subspecies
of cranes and an outgroup, the Limpkin (Aramus guarauna). Levels of s
equence divergence coincide approximately with current taxonomic ranks
at the subspecies, species, and subfamilial level, but not at the gen
eric level within Gruinae. In particular, the two putative species of
Balearica (B. pavonina and B. regulorum) are as distinct as most pairs
of gruine species. Phylogenetic analysis of the sequences produced re
sults that are strikingly congruent with previous DNA-DNA hybridizatio
n and behavior studies. Among gruine cranes, five major lineages are i
dentified. Two of these comprise single species (Grus leucogeranus, G.
canadensis), while the others are species groups: Anthropoides and Bu
geranus; G. antigone, G. rubicunda, and G. vipio; and G. grus, G. mona
chus, G. nigricollis, G. americana, and G. japonensis. Within the latt
er group, G. monachus and G. nigricollis are sister species, and G. ja
ponensis appears to be the sister group to the other four species. The
data provide no resolution of branching order for major groups, but s
uggest a rapid evolutionary diversification of these lineages.