Danaus plexippus
Description
Wanderers (or Monarchs) are large butterflies with orange-brown wings with black veins and a black and white spotted band along the edge of the wings. The caterpillar is distinctive, with black, white and yellow stripes across its body. It has two pairs of black tentacles – a longer pair at the front of the body and a shorter pair on the eighth body segment. They are found in both urban and rural areas where they can find their preferred host food plant, the poisonous milkweed. In summer, Wanderers are found throughout their range along the east coast of Australia from Queensland to South Australia, and in south-west Western Australia. They are strong fliers and can cover long distances during their adult life, which is about a month to six weeks in summer. During this time they can move to unoccupied areas to find new plants on which to lay eggs. Adult butterflies feed on nectar from flowers to maintain their energy levels as they go. Those Wanderer who are adults during winter leave the inland areas as temperatures drop and migrate towards the coast. In winter, they are known to gather together and hang from the branches of trees in large clusters of thousands of butterflies. This is known as over-wintering.
Adaptations
- Adult butterflies have been recorded at speeds of up to 40 km per hour which assists them to cover large distances and spread into unoccupied arears to find new plants to lay their eggs
- The caterpillars eat the distasteful toxins in the milkweed plant which deters predators from eating them
- The caterpillars' bright colouration is a warning to predators that they are potentially toxic
Feeding relationships
- What I eat: caterpillar - milkweed; adult - nectar from flowers
- What eats me: spiders, Pied Currawong, Black-faced Cuckoo-shrike
Interesting facts
The Wanderer Butterfly is an introduced species from North America which has been present in Australia since 1871 when it was first recorded in Sydney. This is shortly after the poisonous milkweed was introduced to Australia as either a garden plant or accidentally via goods entering the country (i.e. as seeds). Cyclones were most likely to have assisted the adult butterflies from moving from New Caledonia to Australia on their journey from North America.
Acknowledgements: Australian museum, Flickr