Butterflies are booming after drought-breaking rains with large numbers of blue butterflies observed heading north within the Great Sandy Area.
The blue tiger butterfly Tirumala hamata (subfamily Danianae) are mostly a tropical butterfly and the longest-lived of all species (up to six months). A close relation of the better known wanderer and lesser wanderer butterflies, sharing several traits with them.
They feed commonly on toxic Asclepiadacea (milkweed) plants and vines including the corky milk vine (Secamone elliptica) on K’gari. These plants contain several poisonous chemicals that prevent most animals predating on it, except the blue tiger larvae. The larvae consume the vine which allows the poisonous chemicals to pass to the shiny green pupae which have golden spots, and adult butterflies. These toxins also assist in protecting adult butterflies from being eaten by birds, as they have learnt they get sick from ingesting blue tigers.
They are strong but slow flyers, having been recorded as far away from Australia as Lord Howe Island, Norfolk Island and New Zealand. Long periods are spent resting in sheltered areas by the tens of thousands during winter.
At this time of year, they migrate north. Large clouds of tens of thousands have been seen flying along the eastern QLD coastline past Cooloola and K’gari.
Article contributed by the NRM team, QPWS&P, Great Sandy National Park