Bollmer,
J. L., R.T. Kimball, N. K.
Whiteman, J. H. Sarasola, and P.G. Parker.
2006. Phylogeography of the Galápagos Hawk (Buteo
galapagoensis): a recent arrival to the Galápagos
Islands. Molecular
Phylogenetics and Evolution 39: 237-247.
Galápagos hawks (Buteo galapagoensis)
are one of the most inbred bird species in the world, living in small,
isolated island populations. We used mitochondrial sequence and nuclear
minisatellite data to describe relationships among Galápagos
hawk populations and their colonization history. We sampled 10
populations (encompassing the entire current species range of nine
islands and one extirpated population), as well as the Galápagos
hawk’s closest mainland relative, the Swainson’s hawk (B. swainsoni).
There was little sequence divergence between Galápagos and
Swainson’s hawks (only 0.42% over almost 3 kb of data),
indicating that the hawks colonized Galápagos very recently, likely less than 300,000 years ago, making them the most
recent arrivals of the studied taxa. There were only seven, closely
related Galápagos hawk haplotypes, with most populations being
monomorphic. The mitochondrial and minisatellite data together
indicated a general pattern of rapid population expansion followed by
genetic isolation of hawk breeding populations. The recent arrival,
genetic isolation, and phenotypic differentiation among populations
suggest that the Galápagos hawk, a rather new species itself, is
in the earliest stages of further divergence.