Rats and prions at Tristan da Cunha Island. (2nd July 2020)

• Record Type: Journal Article
• Authors: Dilley, Ben J; Davies, Delia; Repetto, Julian; Swain, George; Ryan, Peter G
• Is Part Of: Ostrich. Volume 91:Number 3(2020)
• Page Start: 240
• Page End: 243
• Publication Date: 2020-07-02
• Subjects: burrow-nesting petrels -- egg depredation -- island invasives -- rat depredation -- seabirds; Birds -- Periodicals; Birds -- South Africa -- Periodicals; 598.05
• DOI: 10.2989/00306525.2020.1771622
• Languages: English
• ISSNs: 0030-6525

Abstract

Abstract : Tristan da Cunha is a 96 km 2 volcanic island in the South Atlantic Ocean. Black Rats Rattus rattus reached the island from a shipwreck in 1882 and their depredation of seabirds' eggs and chicks are likely partly responsible for the much lower densities of burrow-nesting petrels, compared with adjacent rodent-free islands in the archipelago. We monitored a colony of Broad-billed Prions Pachyptila vittata breeding in a coastal cliff cave in 2015/2016, where a maximum of 6% of chicks survived from 310 nests. We suspect rats frequently depredated eggs (36% of eggs were found broken with rat bite marks) and infrared trail cameras recorded how rats repeatedly hassled chicks, although no direct chick depredations were recorded.