Noun
Either one of two species of birds composing the genus Chionis, and family Chionidae, native of the islands of the Antarctic seas.
Source: Webster's dictionaryAlthough not a true seabird, the Heard Island subspecies of the black-faced sheathbill also breeds on the island. Source: Internet
All recorded breeding species, other than the Heard Island sheathbill, are listed marine species under the Australian Environmental Protection and Biodiversity Act (1999, four are listed as threatened species and five are listed migratory species. Source: Internet
Both the shag and the sheathbill are endemic to Heard Island. Source: Internet