Tristan Thrushes or Starchies Nesocichla eremita are known to feed on seabird eggs. We show they are able to open the eggs of birds as large as small albatrosses. Starchies were involved in almost half of all egg losses by Great Shearwaters Puffinus gravis during the early incubation period in a small study colony at Inaccessible Island, South Atlantic Ocean. They also enter burrows to remove and kill petrel chicks up to at least 70 g. Starchies are thus potentially significant predators of seabird eggs and chicks, and may select against egg neglect and early cessation of brooding by burrowing petrels at the Tristan islands. Starchies previously were recorded killing adult White-bellied Storm Petrels Fregetta grallaria at Inaccessible Island. This behaviour now includes White-faced Storm Petrels Pelagodroma marina. It is likely that the Starchies hunt adult storm petrels directly, taking them from their burrows.