PAC: Tiny frog lives long in NZ's "comfortable" climate
By Tamara McLean, New Zealand Correspondent26 Mar 2009 3:09 PM
AUCKLAND, March 26 AAP - New Zealand's chilly climate might not be celebrated by all, but for frogs it's the secret to long life.
"In frog terms, it's very comfortable here and it helps them to live longer," says researcher Ben Bell, revealing that the country is home to the oldest living wild frog.
The tiny Maud Island frog, a threatened amphibian found only across the ditch, has reached the grand age of 37, the oldest recorded age of any frog out of captivity.
"That makes him a geriatric in frog terms, not that you'd know to look at him," says Prof Bell, of Victoria University in Wellington.
"Australia has some amazing frogs that do very interesting things, but I don't know of any as long lived as these ones."
Prof Bell has tracked the lone population on Maud Island in the South Island for 25 years to discover the oldest three are now at least 34, 35 and 37.
"They could be even older than this, and they may just keep on living for years to come. We just don't know."
He said the secret to their longevity appeared to be New Zealand itself.
"Animals tend to do this in New Zealand, live for a very long time, like the geckos and the (rare reptile) tuatara and the frogs are just following suit," Prof Bell said.
"There's something about the very comfortable climate, the few extremes in weather, that works for them and allows them to just keep on going."
The species, less than 5cm in length, has already made the record books as the world's most primitive frog, as evidenced by extra vertebra and ribs in its skeleton.
They are also unusual in that they don't croak and cannot hear well, because they don't have external ears like modern frogs.
"They've also got these large eyes almost like headlights on a Volkswagen Beetle that help them see in the dark," Prof Bell said.
And unlike most species found in Australia, the Maud frogs are ambush feeders, preferring to just sit and wait for the food to come to them.
The population remains stable at 25,000 frogs, largely because their island home is predator-free.
AAP tam/jl
