Long distance travellers
Every few years we see an abundance of Australian butterflies migrate. Blue Tigers (Tirumala hamata) and Caper Whites (Belenois java) are among them. Some of our butterflies travel long distances.
During Spring and Summer Blue Tigers come from northern Queensland to our area, and may continue their journey further south, even reach Victoria. Especially in seasons with increased rainfall, when Corky milk vine (Secamone elliptica) and Mangrove wax flower vine (Cynanchum carnosum) thrive and provide abundant food for larvae, you can't miss the sheer number of blue patterned butterflies travelling through, only to return north when temperatures start dropping.
Timing is everything, even for butterflies. Combine good rainfall benefiting larval host plants with the warmer season, and you may see large, if not vast numbers of Caper Whites come from the Toowoomba Range and descend on Brisbane in pursuit of their larval host plants, Capparis spp. Again, at the end of the season adult butterflies return to protected gullies near Toowoomba. They put their life on hold and overwinter in clusters until conditions are ripe to move again.
World famous is another butterfly with its migration taking place outside of Australia. When temperatures drop, Monarch butterflies travel in their millions from north eastern Canada and the United States to sourh western Mexico to overwinter. In the northern hemisphere spring they return first to Texas where they breed and their larvae feed on milkweed until a new generation of adult butterflies can fly another few hundred kilometres to repeat the process. It takes several generations to reach the point where the migration started, only to be repeated once the temperatures drop again.
Images:
Top: Blue Tiger (Tirumala hamata) - Bottom: Monarch (Danaus plexippus, left) and Caper White (Belenois java, right). - All images by Sylvia Alexander.