A rare native butterfly, known as the forest ringlet, has been found thriving on Hauturu/Little Barrier Island. Numbers of the butterfly have been in severe decline due to introduced predators over the past 20 years.
The distinctive orange, black, white and yellow butterfly was once widespread in forests throughout New Zealand but is now found only in a few remote areas, and has not been seen in the Auckland region for many years.
The Department of Conservation has hailed the sightings as possibly the most significant event for Little Barrier in five years.
The sightings were made by a senior conservation specialist from Butterfly Conservation in England, Steve Wheatley, who recently travelled throughout NZ documenting known locations and sightings of the forest ringlet.
The project was funded by Lottery Environment and Heritage, supported by Moths and Butterflies of NZ Trust and directed by entomologist Dr Peter Maddison, former president of Forest and Bird. Dr Maddison says declining numbers of forest ringlets were first observed during the 1990s and it is thought the vespula wasp, or common wasp, contributed to the reduced numbers.
The species is endemic to NZ and has no close relatives.
Dr George Gibbs, entomologist at Wellington’s Victoria University, says the butterflies were probably found at Little Barrier because of the island’s rodent-free status, the fact that vespula wasp numbers are low there, and because it is the ‘disconnected north end’ of the Coromandel. He says it makes the island worthy of further study.
The forest ringlet lives in forest glades, from near sea-level to the treeline, and is usually found in late summer when they fly high in the forest canopy. Females can also be seen on or near sedges, rush-like plants, where they lay their eggs.