Above picture: Now safe from aliens: a Grey Petrel chick resides in its burrow on Macquarie Island; photograph by Jeremy Bird

A recent open-access publication in the journal Conservation Biology details the encouraging recovery of four species of burrowing petrels on Australia’s sub-Antarctic Macquarie Island, following the removal of the last of its introduced mammals by the Macquarie Island Pest Eradication Project (MIPEP) over 2011-2014.

The paper’s abstract follows:

“Eradicating invasive predators from islands can result in substantial recovery of seabirds, but the mechanisms that drive population changes remain poorly understood.  Meta-analyses have recently revealed that immigration is surprisingly important to the recovery of philopatric seabirds, but it is not known whether dispersal and philopatry interact predictably to determine rates of population growth and changes of distribution.  We used whole-island surveys and long-term monitoring plots to study the abundance, distribution, and trends of 4 burrowing seabird species on Macquarie Island, Australia, to examine the legacy impacts of invasive species and ongoing responses to the world’s largest eradication of multiple species of vertebrates.  Wekas (Gallirallus australis) were eradicated in 1988; cats (Felis catus) in 2001; and rabbits (Oryctolagus cuniculus), black rats (Rattus rattus), and mice (Mus mus) in 2011–2014.  We compared surveys from 1976–1979 and 2017–2018 and monitoring from the 1990s and 2000s onward. Antarctic prions (Pachyptila desolata) and white-headed petrels (Pterodroma lessonii) increased ∼1% per year.  Blue petrels (Halobaena caerulea) and gray petrels (Procellaria cinerea) recolonized following extirpation from the main island in the 1900s but remained spatially and numerically rare in 2018.  However, they increased rapidly at 14% and 10% per year, respectively, since cat eradication in 2001.  Blue and gray petrel recolonization occurred on steep, dry, west-facing slopes close to ridgelines at low elevation (i.e., high-quality petrel habitat).  They overlapped <5% with the distribution of Antarctic prion and white-headed petrels which occurred in suboptimal shallow, wet, east-facing slopes at high elevation.  We inferred that the speed of population growth of recolonizing species was related to their numerically smaller starting size compared with the established species and was driven by immigration and selection of ideal habitat.”

Overall burrow numbers (a) and breeding success (b) of four petrel species on Macquarie Island; from the publication

Two of the burrowing petrels that are recovering on Macquarie also breed on Marion Island, namely the Blue Petrel and the Grey Petrel.  They are both known or suspected to be attacked and killed by the island’s introduced House Mice Mus musculus.  The Mouse-Free Marion Project has every hope that once it eradicates Marion Island’s mice, we shall see an equally encouraging recovery of these two and all its other species of burrowing petrels.

“At night, Blue Petrels come ashore to their nests, now back on the main island since pests were eliminated”; photograph by Jeremy Bird

It is noteworthy that the leader of the award-winning MIPEP, New Zealander Keith Springer, is now the Operations Manager for the Mouse-Free Marion Project – we are in safe hands!  Another pleasing international connection is that a co-author of the Macquarie paper featured here, Justine Shaw, is no stranger to Marion and Prince Edward Islands, having spent time conducting research on both while holding a post-doctoral fellowship at the University of Stellenbosch’s Centre for Invasion Biology in South Africa.  As the African proverb says, “it takes a village”!

Read a popular account of the scientific publication here.


Bird, J.P., Fuller, R.A. & Shaw, J.D. 2023.  Patterns of recovery in extant and extirpated seabirds after the world’s largest multipredator eradication.  Conservation Biology doi.org/10.1111/cobi.14239.

John Cooper, News Correspondent, Mouse-Free Marion Project, 05 March 2024


A Southern Giant Petrel pair on Marion Island; photograph by Janine Schoombie and poster design by Michelle Risi

The Mouse-Free Marion Project is a registered non-profit company (No. 2020/922433/08) in South Africa, established to eradicate the invasive albatross-killing mice on Marion Island in the Southern Ocean.  The project was initiated by BirdLife South Africa and the South African Department of Forestry, Fisheries and the Environment.  Upon successful completion, the project will restore the critical breeding habitat of over two million seabirds, many globally threatened, and improve the island’s resilience to a warming climate.  For more information or to support the project please visit mousefreemarion.org.