Bringing back native predators to tackle invasive species crisis

Bringing back native predators to tackle invasive species crisis - Queens University Belfast

Restoring native predator populations could help to keep in check some of the most problematic invasive species around the world, suggests a new study led by Queen’s University Belfast and Cornell University.

Invasive species are one of the greatest threats to biodiversity globally and are the main cause for the extinction of vertebrates in the last century, with an estimated cost of at least $162 billion (USD) a year.

Native predator populations have been depleted globally, despite being essential for the functioning of the ecosystem and biodiversity. The absence of native predators facilitates the spread of invasive species leading to the extinction of native species throughout the world.

head of lynx looking out between trees — (image: Markus Wittmann)

The research, published today (16/6) in Global Change Biology, found that restoring native predators could provide a solution to a variety of the most damaging invasive species globally. According to the study, the evolutionary naivety of invasive species to native predators, coupled with a lack of spatial refuges from predation could underpin the abilities of native predators to provide effective control of certain established invasive species.

The research team have previously shown how the recovery of the native pine marten in the UK and Ireland has resulted in landscape-scale declines of the invasive grey squirrel. Building on this research, the team have now evaluated native predator reintroduction and restoration as a viable nature-based solution to the invasive species crisis.

One example shows how re-introducing the native lynx could help to manage one of the most damaging invasive species to the environment in Europe, the sika deer. Sika deer are considered a pest as they graze on crops and “ring” trees, stripping the bark from the base and causing the tree to die. They are also thought to contribute to the spread of diseases such as bovine and avian TB. The new research provides strong evidence that the lynx could impact sika deer populations in Britain and Ireland. It also shows how the lynx and wolf recovery in Europe could limit raccoon dogs below the threshold for rabies persistence, which remains a huge threat to human and animal health.