In 1837, New Zealand imported possums for a fur trade; 189 years later, aerial photos show they have damaged about half the vulnerable trees in one rare South Island forest

• PossumsRepresentative imageIn 1837, New Zealand introduced Australian brushtail possums in the hope of building a profitable fur industry.
• The animals were expected to provide valuable pelts and help create a new rural economy, but the experiment had consequences that stretched far beyond anyone’s expectations.
• Nearly two centuries later, possums have become one of the country’s most damaging introduced pests, feeding on native plants, competing with wildlife and spreading disease.