Masses of orange-brown butterflies are currently moving through the Blue Mountains, and no doubt other parts of south-eastern Australia. These are Australian Painted Ladies, Vanessa kershawi, flying south (or south-west) on their spring migration.
I don’t remember ever seeing as many as I have this week — streams of them crossing the highway at Mount Boyce, for example. I can’t help wondering how far each one has flown, and where they’re going. The migration is said to be greatest in years when there has been high winter rainfall, and that’s certainly the case this year. Australia had its second wettest winter on record and NSW its third wettest winter in 2016.
Walking on Kings Tableland it seemed like I was walking through clouds of butterflies. They frequently rested on the sandy track, wings outspread, oriented towards the sun. The males do this not only to warm themselves but to attract females.
While the majority were Australian Painted Ladies, there were a few Meadow Argus (Junonia villida) flying among them.
The migration can continue for 8 weeks, according to the Australian Museum website, which also tells us:
“In 1889, the Australian Painted Lady was reported to migrate in such great numbers that they blackened the sky. Trains were unable to get traction because so many butterflies were resting on the tracks! Such mass migrations have not been reported for some time.”
Now that would have been something to see!
The Australian Painted Lady lays its eggs on plants of the daisy family (Asteraceae), such as native everlastings and the introduced Capeweed and Scotch Thistle. Life cycle is about 53 days, with several generations completed in a year.