Hawke’s Bay locals urged to help track sightings of in-decline monarch butterflies

Monarch butterflies overwintering in Christchurch this year. Photo / Kathy Reid

The number of monarch butterflies is dropping across the country and an expert is concerned that the traditional winter spots in its home region are disappearing.

There has been a roughly 10% drop in the number of monarchs sighted in New Zealand over the past 20 years, and the Moths and Butterflies of New Zealand Trust is calling on the public to help find them.

First officially spotted in Aotearoa in 1841 in Wairoa, the butterfly gathers in traditional clusters in trees for warmth and survival during winter.

Unlike summer monarchs, which typically live for six to eight weeks, those in the “overwintering” groups can survive up to six months, founding trustee Jacqui Knight told Hawke’s Bay Today.

While some of them have been reported in a couple of New Zealand’s parks this year, none have been recorded in Hawke’s Bay, which once had multiple known sites.

“We’re urging people to report monarch butterflies overwintering,” says Knight.

“We’ve set up a special page on iNaturalist where people can report these groups. Dr David James at Washington State University is leading the scientific side of the initiative.”

While high-tech GPS trackers are used in North America, New Zealand relies on a simpler, yet effective tagging system.

More than 4000 monarchs were tagged over the 2024/25 season, each marked with a small, lightweight sticker that contains a unique code and website link.

Recently, a monarch’s journey was tracked from Feilding to Clive.

“It was done in 22 days. That’s quite a long flight,” Knight said.

Historically, overwintering clusters in Hawke’s Bay have been spotted at sites such as Anderson Park, Cornwall Park, and Frimley Park, Taradale, and Clive.

But their current status is unknown, and Knight hopes local knowledge will help confirm whether monarchs are still returning to those locations.

“We need the help of nature lovers,” she says.

“Next time you are out in nature, help our monarchs - look up.”

If you spot a monarch cluster or tagged butterfly, you can report it at iNaturalist.nz or visit www.nzbutterflies.org.nz for more details.