Suwarrow Atoll Rat Eradication and Seabird Monitoring (Cook Islands)

Suwarrow National Park is a remote, uninhabited coral atoll roughly 930 km northwest of Rarotonga, hosting seabird colonies of global significance, including a large share of the world's lesser frigatebirds alongside sooty terns and red-tailed tropicbirds. A 2008 seabird survey found that black noddies, present on the islet of Motu Tou in a 2000 survey, had disappeared, and identified a rat infestation as the cause.

In response, the Cook Islands National Environment Service, working with BirdLife International and the local NGO Te Ipukarea Society, ran a rat-eradication operation using cereal bait pellets containing the anticoagulant brodifacoum from 22 April to 29 May 2013. Ongoing biosecurity management was subsequently handed to an on-site National Environment Service park ranger stationed seasonally on the atoll.

Follow-up monitoring in 2018 found the operation had not fully succeeded: a remnant rat population was detected persisting on one small lagoon islet, showing that eradication on a multi-islet atoll remains incomplete more than a decade after the original operation. The case illustrates both the conservation stakes of invasive-rodent control on remote Pacific seabird strongholds and the practical difficulty of achieving total eradication across dispersed, hard-to-access islets.

Read the full analysis: https://www.maraemoana.gov.ck/marine-park-news/rat-eradication-in-suwarrow-cook-islands/