A kaleidoscope of butterflies have been seen swarming the region over the past week.
Up to 500 Monarch butterflies have inhabited a tree in Taradale.
Secretary of the Monarch Butterfly New Zealand Trust, Jacqui Knight said it wasn't unusual to see this behaviour, known as 'overwintering' during the winter months.
"Monarch butterflies go into diapause at the end of summer. The adult butterflies that hatch in late autumn are sexually mature but won't breed until spring. A monarch might live for six to eight weeks after it has finished reproducing during the summer, but the winter generation of monarchs may live up to nine months," Ms Knight said.
"There are much smaller overwintering sites up and down the country, than those seen overseas. This is how they survive the winter months, by staying in large groups and keeping warm on cold days."
A few are expected not to survive the cooler months, while the strong ones will go on to start a new generation of Monarch butterflies.
Ms Knight, who is currently visiting Hawke's Bay from Auckland was alerted of the sight, after a member reported it.
"We're hoping that if people see this, they will come to our website www.mb.org.nz and report a sighting."
She said it was unfortunate that people weren't looking after the environment as well as they could be.
"Monarch butterflies indicate the health in the environment; it's like a canary in a coal mine. It is a beautiful natural phenomenon that people can see if they look after the environment."