MITOCHONDRIAL DNA SEQUENCE VARIATION AMONG THE SUBSPECIES OF SARUS CRANE ( GRUS ANTIGONE )

--We xamined DNA sequence variation in an 1,831 base-pair segment of the mitochondrial DNA genome from representatives of the three subspecies of Sarus Crane (Grus antigone). The sequences include the entire cytochrome-b, tRNA TM, tRNA Prø, and ND6 genes, as well as three short intergenic spacer regions. Nine distinct haplotypes were identified in a sample of nine individuals, three each from the Indian (G. a. antigone), Burmese (G. a. sharpei), and Australian (G. a. gillae) subspecies. Phylogenetic analysis revealed that although Sarus Crane haplotypes form a monophyletic assemblage relative to Brolga (G. rubicunda) and White-naped Crane (G. vipio) outgroups, they cannot be resolved onto a dichotomously branching tree. A minimum-length network for the Sarus Crane haplotypes reveals at least one instance of direct ancestry and one hard polytomy, but shows no phylogeographic partitioning of haplotypes among subspecies. Net sequence divergence among subspecies is not significantly different from zero. Estimated sequence divergence times, neutral coalescent imes, and data on the Quaternary geology of Australasia suggest hat Sarus Cranes colonized Australia during the late Pleistocene. Received 25 October 1995, accepted 10 December 1995. $ARUS CRANES (Grus antigone) are among the largest members in the crane family (Gruidae), sometimes reaching an adult height of 1.8 m. They are nonmigratory and currently found in isolated areas of northwestern India, Southeast Asia, and Australia. Blyth and Tegetmeier (1881) classified the Indian and Burmese Sarus Cranes as distinct species on the basis of plumage and body-size characteristics (the larger Indian Sarus Crane has a bright white neck ring and white tertials), and this distinction persisted through the classification of Sharpe (1894). Blanford (1895), however, reduced the Indian and Burmese Sarus Cranes to subspecies (G. a. antigone and G. a. sharpeL respectively), and this convention endured through all subsequent revisions. Sarus Cranes were first observed in Australia in 1966, and were then considered members of G. a. sharpei (Gill 1969, Archibald 1981). Schodde (1988) designated the Australian Sarus Crane as a distinct subspecies (G. a. gillae) on the basis of its darker plumage and larger ear patch. The range of the Sarus Crane has been dra• Present address: Laboratory of Medical Genetics, University of Alabama, Birmingham, Alabama 35294, USA. 2 Address correspondence to this author. E-mail: careyk@siu.edu matically reduced by human activity during the past century. Once widely distributed across India, Nepal, Bangladesh, and western Burma, the Indian Sarus Crane is now restricted to portions of northwestern India and the Terai lowlands of Nepal (Johnsgard 1983). Until the late 1940s, Burmese Sarus Cranes were found in southern China, eastern Burma, Philippines, the Malay Peninsula, Thailand, Cambodia, Laos, and Vietnam (Delacour and Mayr 1946, Walkinshaw 1973, Meine and Archibald unpubl. report) but have now been extirpated from all but the latter three areas (Medway and Wells 1976, Madsen 1981, Yang 1991). The Australian Sarus is currently found in northern Queensland from Normanton north to Aurukun, east to the Atherton Tableland, and west to Kunnunurra in