The Tasmanian devil has had a rough time in the past 30 years, with their population having been pushed to the brink by the spread of a contagious form of cancer known as devil facial tumor disease (DFT). Multiple approaches have been taken to try and conserve the species, but, according to Wionews, a recent report from BirdLife Tasmania appears to reveal that one technique has caused devastation for an entirely different animal.
In an effort to establish a reserve population geographically isolated from DFT, Tasmanian devils were introduced to Maria Island, a small habitat that sits to the east of Tasmania. The tiny island was a haven for little penguins (Eudyptula minor), ground-dwelling and nesting birds that are the smallest penguins on Earth. Unfortunately, it seems their small stature and limited defenses made them easy pickings for the island’s new residents, and it’s thought that the Tasmanian devils have now wiped out the breeding population of around 6,000 little penguins.
The worrying trend has been observed since the devils’ introduction in 2012, but a recent survey conducted by BirdLife Tasmania states that the penguins have now completely disappeared.
“Every time humans have deliberately or accidentally introduced mammals to oceanic islands, there’s always been the same outcome… a catastrophic impact on one or more bird species,” said Dr Eric Woehler, the convenor of BirdLife Tasmania to the Guardian. “Losing 3,000 pairs of penguins from an island that is a national park that should be a refuge for this species basically is a major blow.”
Little penguins are found on the shores of Australia and New Zealand, two regions of the globe that are uncomfortably familiar with the devastating potential of introduced species, as countries that are home to ground-nesting birds. In New Zealand, possums were introduced deliberately in 1837 with hopes of establishing a fur trade, but despite naive hopes their presence might enrich the country’s biodiversity, instead it preyed upon native species including the iconic kiwi and competed for burrows with little penguins.
In the case of the Tasmanian devils, the threat these animals pose to little penguins is worse even than that of possums and domestic cats who are also partial to bothering these little birds. According to Woehler, it’s not just the penguins who are suffering as a result of the devils' human-aided arrival.
“We’re getting reports of geese trying to nest in trees to avoid devil predation,” he said. “It’s very clear that the devils have had a catastrophic ecological impact on the bird fauna on Maria Island.”
[H/T: The Guardian]