Surprise at number of rare frogs

It's estimated only 5000 to 20,000 Archey's frogs are left. Photo / Sarah Ivey

Expert ‘very excited’ by survey on endangered species, but worried it was done for firm hoping to mine land.

The discovery of 44 critically endangered Archey's frogs just a few kilometres from Whangamata has heartened an amphibian expert.

But Dr Phil Bishop, a professor of zoology at the University of Otago, was concerned to learn the frogs had been discovered in a survey ahead of proposed mining prospecting.

Archey's frogs, our smallest native frogs, are found in only two parts of the country - the Whareorino Forest west of Te Kuiti and the Coromandel Peninsula.

Their total population is estimated at between 5000 and 20,000.

Professor Bishop said the species had experienced a sharp decline when a disease spread northward into the south of the Coromandel Peninsula.

He told the Herald he was "very excited" when he recently learned a survey had spotted 44 frogs in the area.

"I don't think I've ever been on a trip where we've found 44 frogs," he said.

"Normally, if you do a survey of frogs, you find them in a place where they haven't been found before, and even if you find them in a place where they've been found before, you would normally submit them as an endangered animal to the Department of Conservation database.

"But in this case, there was nothing in the database, so I then had to find out what happened and who did the surveys."

Professor Bishop discovered the survey was carried out by ecological consultancy Wildlands, who had been contracted by mining company Newmont Waihi Gold.

The survey was done in December 2012 at five sites, 10km southwest of Whangamata, to be potentially used by the company for prospecting. Over a 33-hour period, the survey identified 30 adult Archey's frogs and 14 juveniles.

Newmont spokesman Kit Wilson said the firm had chosen not to establish 10m-by-10m drilling sites at four of the sites. At the fifth, it had established a buffer zone to ensure impacts were minimal.