island conservation palmyra atoll line islands rays

The Research is Clear: To Prevent Extinctions, Restore Islands

A paper published recently in the Proceedings of the National Academy of Sciences details how invasive species removal can restore island ecosystems and protect native species. 

Ecosystems around the world suffer from the presence of invasive species. Invasive species, when introduced to a foreign environment, can cause sudden and disastrous shifts in the ecosystem. Although invasive species erode ecosystem vitality around the world, islands are particularly vulnerable. Many islands are home to species that live nowhere else on Earth. Islands make up only 5.5 percent of Earth’s land area, yet are home to an incredibly high level of biodiversity.

island conservation photo of mona island

The view from Mona Island, Puerto Rico. Tommy Hall/Island Conservation

Following the arrival of invasive species, which usually happens through human introduction, the destruction on islands is fast and furious; invasive predators dig into native species populations without restraint. A paper published recently in the Proceedings of the National Academy of Sciences details how invasive species removal projects benefits island ecosystems.

Nick Holmes, a co-author on the paper and director of science at the non-profit organization Island Conservation said:

Once invasive mammals were introduced to those islands, accidentally or on purpose, they would turn around and quickly dominate.

Among the worst of the invaders are rodents and feral cats. These predators prey on ground-dwelling birds and other island species. Rats are quick to snatch up bird and reptile eggs, which severely stunts native populations. Conservation biologist Holly Jones of Northern Illinois University and lead author on the research paper noted:

Rats are completely widespread. They’ve been introduced to over 90 percent of the world’s archipelagoes.

Jones notes that feral cats are known as “super predators,” causing incredible damage on islands because “They don’t only hunt what they need to eat. They hunt for fun.

island conservation science red-tailed tropicbird chick

Chicks like this White-tailed Tropicbird are vulnerable to invasive predators. Photo credit: Peter Kappes

The research paper revealed that 236 island species have benefited from the removal of invasive species from 181 islands. Projects to remove invasive species from the Galapagos, for example, have enabled species like the Pinzon Tortoise to avert extinction.

In the world of conservation, it’s rare to find a strategy that very clearly works so well.

island conservation science giant tortoise pinzon island

Pinzon Tortoises were classified Extinct-in-the-wild for over 100 years. Following the removal of invasive rodents from Pinzon Island, this rare species is now flourishing in the wild. Photo credit: Island Conservation

Without conservation intervention, island ecosystems infested with rodents or other invasive species are unable to rebalance themselves. Such biodiversity hotspots, which take millennia to evolve, are at risk of becoming extinction epicenters over the course of mere decades. Jones notes:

The act of not doing anything to prevent these extinctions is, in and of itself, an action—which is not compassionate to native species. We can sit there and watch animals go extinct, or we can do something about it.

island conservation french polynesia tutururu

Island Conservation’s Program Manager Kirsty Swinnerton handling a Polynesian Ground Dove, or Tutururu, a ground-dwelling island bird. The Tutururu is Critically Endangered due to invasive species impacts. Photo credit: Island Conservation/Maddy Pott

The removal of invasive species from island ecosystems is a proven way to protect biodiversity and prevent extinctions. Native species lives are at stake, and we have the knowledge and tools to save these lives. Jones says:

When you realize the gravity of not acting, which in many cases equates to watching extinction happen in front of your eyes, I think there is no other choice.

Source: TVN

Featured photo: Palmyra Atoll, Line Islands. Photo credit: Aurora Alifano
Original research press release: PNAS

About Sara Kaiser

Sara received a BA in anthropology from UC Santa Cruz in 2014. As a freelance writer and editor, she seeks to produce and highlight stories that support ecological responsibility, body awareness, emotional intelligence, and creative action, and reveal the connections between them.

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