The behaviour of Monarch butterflies over the winter is being continually monitored by members of the Monarch Butterfly NZ Trust as well as a band of citizen scientists.
“Some Monarchs are overwintering in the very same suburbs in which they were bred,” said Jacqui Knight, secretary of the Monarch Butterfly NZ Trust.
“Although there used to be large populations in trees in Christchurch parks, we have had no sightings reported of overwintering Monarchs in Christchurch,” she said. “Have the Monarchs moved on – or more likely it was because our citizen scientists there have higher priorities?”
In America, their country of origin, Monarch butterflies can fly from as far north as Canada up to 3000 kilometres south to Mexico, to wait out the winter in protected reserves. At the first signs of spring the survivors return northwards, to initiate the new generation of Monarchs that grace gardens and wilderness areas – wherever milkweed grows.
The Trust is keen to enlist the help of other New Zealanders in the project.
“Several clusters of Monarch butterflies were reported around the Wellington region this past season,” Jacqui added, “and more in the Nelson area.”
If we are to conserve species effectively, it is vital we monitor how they are faring.
“The status of our flora and fauna depends on the effects of climate change, pollution, alien species and land management,” Norm Twigge, Chairman of the Monarch Butterfly New Zealand Trust said. “We need to know more about our insects to predict the impacts of such change, and to develop an appropriate response.”
“The tagging programme is fantastic and, thanks to the participation of our citizen scientists, providing very useful data. We are learning more about the butterflies’ behaviour each year,” he said.
“Having had over 10,000 sightings of our different species over the five years since the project started, it is noticeable how few are of Kahukura or our Red Admiral, a beautiful species only found in NZ. It would be tragic if we lost this butterfly altogether.”
Butterflies are uniquely placed to act as indicators of environmental change.
“By tagging and following Monarchs, we can use them as indicators of the status of our environment.”
“Tagging serves a dual purpose,” he said. “Not simply by collecting critical data, but also by introducing people to the method and purpose of scientific investigation.”
Monarch butterflies typically form large clusters, sometimes containing hundreds or thousands of butterflies, on trees in well-sheltered areas during the colder winter months. Until the Trust started tracking Monarchs five years ago there was little research being done as to why butterflies appeared to be retreating from urban areas of NZ.
“This is important,” Jacqui said. “Butterflies are pollinators – we need to know why they are becoming less common before they disappear altogether. Already there are major concerns for the Forest Ringlet, a butterfly only found in NZ.”
“I haven’t seen any bees so far in my garden this spring. If the bees are retreating we’re going to be even more dependent on our butterflies and moths for pollination.”
Then it is a simple matter of logging the information in to the website, custom-built for the purpose – www.mb.org.nz. People can record the sighting of one butterfly or clusters in roosting trees.
Tagging will begin again next March. The Trust is keen to involve gardeners, nature-lovers, trampers, schools, and home-schooled children in both tagging and sighting. All the information needed to register and how to play your part is on the Monarch Butterfly NZ Trust