The subspecific origin of the inland breeding colonies of the cormorant Phalacrocorax carbo in Britain

The establishment of cormorant breeding colonies inland within south-east B ritain since 1981 is a matter of major conservation and pest management con cern. This study was initiated to investigate the subspecific origin of two recently established breeding colonies. The analysis examined sequence var iation of the control (D-loop) region of the mitochondrial genome. Samples of tissue were obtained from 334 individuals from across the species range in western Europe from both subspecies (Phalacrocorax carbo carbo and P. c. sinensis) and 84 birds from two ireland breeding colonies in Britain. Sing le-strand conformation polymorphism (SSCP) was used to assess mitochondrial variation among samples, revealing four haplotypes. The samples from the t raditional breeding colonies clustered into three distinct phylogeographic groupings: Norway-Scotland, Wales-England-Iles des Chausey and the rest of Continental Europe. These results only partly agree with the traditional su bspecific taxonomic groupings and are slightly at variance with results usi ng microsatellite DNA frequencies, and a hypothesis using results from both studies is advanced. The subspecific origin of the inland colonies was inv estigated using maximum likelihood and Bayesian models.