We have the marvelous monarch butterfly in New Zealand.
Like many, I try and grow swan plants in my garden, even though they look rather ugly, especially when almost leafless from caterpillar overload, (and yes, I do seem to have some aphids there too, no doubt they have picked up the same poison that makes the monarch so unpalatable to birds) - but the large, bright monarch butterflies are worth it. The football jerseyed larvae are quite arresting too. But the most beautiful stage to my mind, is the pupa; the tiny jade lanterns with their row of gold dots are exquisite!
This time of year as the temperature drops, the butterflies stop mating and look for some where to overwinter. Not much is known about where they overwinter in New Zealand, but apparently they don't usually go far, sometimes just to the nearest park where they might hang out together in a tree.