OVERWINTERING monarchs are mesmerising visitors to Whakatane’s Warren Park this winter.
Clusters of the monarch butterflies (Danaus plexippus), New Zealand’s most identifiable butterfly, have taken up residence in three trees near the children’s playground. Smaller groupings have also been spotted overwintering in the McGarvey Road rose gardens.
There are a lot more monarchs this year, according to enthusiast Martie Sisson who fell in love with the butterflies at a young age. “I just love them – there’s something about them. I’ve just always been interested in them. Even as a child I was always bringing them home.”
She says the monarchs overwinter in Warren Park every winter from about March through to August, then begin breeding around September. Their normal life span over summer is six-to-eight weeks but in winter they can live for up to seven months, she says.
“It is a good sign for us to have them every single winter – and there are a lot more this winter, which is a good thing to see. There’s over a hundred there – they are everywhere.”
Martie tags the monarchs after they hatch for the Monarch Butterfly New Zealand Trust. It’s a simple process that involves sticking a small tag on the inside of their wing.
“They come out of the chrysalis and when they are three or four hours old there’s a tag that’s the size of a fingernail that has a number on it. I put it on the inside of the wing using a toothpick so when they are flying you can see it from underneath, which is really very interesting.
In North America, more than 250 million monarchs leave the United States and southern Canada and fly south to overwintering roosts in west Mexico City but in New Zealand less is known about the monarchs’ overwintering behaviour – where they overwinter and how many sites there are.
In an effort to learn more about where the monarchs overwinter, and how many sites there are, the trust tries to tag the overwintering generation, not those butterflies that emerge through spring and summer.
With the information from the tagging programme, the trust says it will be better prepared to protect monarchs and measure changes to the environment.