Screams betray sneaky killer

Death screams from an Australian frog have produced photographic evidence confirming what naturalists have long suspected but never known for sure.

Massey University philosophy lecturer Stephen Chadwick heard a high-pitched scream at his home in Himatangi Beach about 11pm on Tuesday and went out to investigate.

He found the noise was coming from a frog that was being eaten by a hedgehog.

"I could not believe how loud the scream was from such a small thing," he said. "The noise continued for about two minutes and in the end I got a torch and shone it around the garden."

Otago University amphibian and reptile zoologist Phil Bishop identified the victim as an introduced Australian southern bell frog.

"We have had many anecdotal reports that hedgehogs eat introduced - and probably native - frogs, but so far have not had any direct ‘proof' like this," Dr Bishop said after seeing Mr Chadwick's photos.

New Zealand's two native species - the critically endangered Archey's frog and the vulnerable Hochstetter's frog - are virtually helpless against hedgehogs. They tend to freeze when confronted, and their defensive secretions are less poisonous to hedgehogs than those of introduced species.

"People love hedgehogs, they think they're cute, cuddly and innocuous . . . but they're sort of sneaky killers," Dr Bishop said.

He and a research team will now establish whether hedgehogs are eating native frogs by looking in their stomachs for indigenous frog DNA.

Native frog populations are concentrated in the Waitakere area, the Coromandel and the Raukumara Range, Bay of Plenty.

Contact Matt Stewart
Weather, science and environment reporter
Twitter: @smatape

The Dominion Post