red admiral butterfly of forest margins and nettle patches
- Size
- Length: 5–6 cm, Weight: 0.2–0.4 g
- Lifespan
- 1–2 years
- Diet
- Larvae feed on native nettle (Urtica incisa) and other nettle species. Adults feed on nectar from flowers including hebe, buddleia, and clover. New Zealand's only endemic butterfly.
- Habitat
- Forest edges, scrub, gardens, and open country where its host plant, the pūhā (sow thistle), grows. Sun-worshippers of the canopy, often seen basking on warm leaves.
- Range
- Found throughout the North and South Islands, Stewart Island, and the Chatham Islands in gardens, forest edges, and open country where nettles grow. Most common in lowland areas with diverse flowering plants.
- Endemism
- Endemic
- Main Threats
- Habitat loss from conversion of native grasslands to agriculture and urban development. Loss of native nettle host plants. Pesticide use. Climate change affecting host plant availability.
- Population
- New Zealand's only endemic butterfly. While widespread, their numbers fluctuate with the availability of host plants and the severity of winter. They are a resilient species that has adapted well to both native and modified landscapes.
- Conservation Status
- Not Threatened
The jewel of the New Zealand sky has wings of deep, velvety black slashed with vibrant crimson bands and white spots. It is a striking contrast against the green bush. Unlike many butterflies that flutter aimlessly, the kahukura flies with purpose and speed, often patrolling a specific territory with aggressive determination. Males will chase off intruders, from other butterflies to passing birds, defending their patch of sun with surprising ferocity.
Its life cycle is tightly bound to the pūhā (sow thistle), a plant once considered a weed but now recognised as a vital lifeline. The female lays her eggs singly on the leaves, and the resulting caterpillars are masterful camouflagers, spinning leaves together with silk to create a safe feeding tent. Inside this green fortress, they grow rapidly, shedding their skins until they are ready to pupate. The chrysalis is a work of art in itself, hanging like a golden pendant from a stem, hiding the alchemy of transformation within.
In summer, you will often see them puddling, gathering in damp patches of soil or on animal dung to extract minerals and salts that nectar cannot provide. It is a communal, messy affair that belies their elegant appearance. They are one of the few butterflies that hibernate as adults, finding shelter in hollow trees or sheds to wait out the cold months. They emerge in spring to start the cycle anew. To see a red admiral basking in a shaft of sunlight is to witness a flash of living stained glass, a reminder of the beauty that thrives in the margins.
The red admiral has also become a symbol of urban conservation. Unlike many native insects that retreat from human habitation, this butterfly has adapted to city gardens. Plant some nettles in a corner, leave a patch of clover unmown, and they will come. They do not ask for wilderness. They ask for tolerance. That makes them one of the most accessible pieces of wild beauty in New Zealand. A child can watch a caterpillar become a chrysalis on a nettle plant behind the garage. That transformation never gets old.