(a) The likely global distribution of Gray's beaked whales (M. grayi) based on both sightings and stranding records (follows International Union for Conservation of Nature listing, www.redlist.org). (b and c) Location of Gray's beaked whale samples and a priori geographic regions. Stranding locations for samples are shown by black circles and sample numbers are given within parentheses. A priori regions are shown by colour (West Australia (purple), in New Zealand, North East (blue), North West (green), South East (orange) and South West (yellow)). For details of actual stranding locations, see Supplementary Information.