Conservation conundrum: Invasive species like nature reserves too

male ruddy duck
© Chris Gomersall for RSPB. A male ruddy duck.

The North American ruddy duck is a beautiful creature, but its presence in nature preserves in the United Kingdom may not be good news for native species. Ruddy ducks, which were brought by humans to the UK in the 1930s and 40s, are a threat to the European white-headed duck.

Scientists at University of York and the Royal Society for the Protection of Birds (RSPB) have identified seven non-native species of birds that are now established in the UK, and are increasingly associated with reserves and protected nature areas.

In addition to the ruddy duck, the non-native species are the Canada goose, the Egyptian goose, the black swan, the Mandarin duck, and the barnacle goose. Most of these species were introduced to the UK by people to be part of menageries or for sport hunting.

© Amanda Wright. Black swan with cygnets.

Nature reserves have been found to help native European bird expand their habitats, but this progress could be offset by invasive competitors. The research was recently published in the journal Diversity and Distributions.

"Invasions are becoming increasingly common across the world, and might threaten the survival of native species,” said researcher Jonathan Hiley in a press statement. “It is essential that conservationists take note of these results and monitor the spread of non-natives.”

However, the challenge is to identify if the invasive species will actually cause problems or not. Some foreign species may be able to co-exist without becoming a problem for native species. “The introduced North American Ruddy Duck disproportionately colonized protected areas and is a potential threat to the native European White-Headed Duck,” said Chris Thomas, a professor of Biology at University of York. “In contrast, the colorful Mandarin Duck is less frequently associated with reserves, and is unlikely to cause ecological damage even when it does colonize them.”

The researchers write that careful monitoring of invasive species and early action is key to preventing problems in nature reserves.

What’s to be done when a problem is likely? Our vegan readers probably won’t like the answer. In the case of ruddy ducks, the RSPB supports eradication—typically by hunting. The organization states on its website that the position is based on detailed research and that “we are faced with a stark choice: either we act to stop ruddy ducks spreading from the UK, or we stand by and watch as the white-headed duck is pushed ever closer to extinction.”

Tags: Biodiversity | Birds | United Kingdom

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