And Now For Something Completely Different: NZ Frogs "Jump to Oblivion"

A worldwide decline of frogs could point to serious environmental problems, a University of Otago amphibian expert said at the beginning of this International Frog Week.

"They've been likened to canaries in the coalmines; if something is going on with the frogs then it's a sure sign there's something going on in the environment," zoology senior teaching fellow Dr Phil Bishop said.

More than a decade ago, almost 1400 amphibian experts gathered for a conference at the University of Kent, in England, and began to compile anecdotal evidence of the decline.

Since then research into the problem has begun in earnest. As a result experts have concluded that frog populations around the world are declining.

Dr Bishop, New Zealand chairman of the Declining Amphibian Population Task Force, said: "People realised something funny was happening to frogs and we set up a taskforce to find out if this was a real thing."

He said several theories to explain the decline had been considered, though not agreed on.

Suspects include increased ultra-violet rays as a result of the depleting ozone layer, increased exposure to pesticides and herbicides and exposure to a chytrid fungus, which may be proving fatal.

Dr Bishop, who is co-ordinating Frog Week in New Zealand, said frogs were particularly vulnerable to changes in the environment because their moist skin easily absorbed water and they were vulnerable to air changes. Any pollutants could therefore have a serious impact. Frogs also played a key role in the ecosystem.

"All creatures have a role to play in the environment. I liken it to the rivets on a plane; you can lose a certain number, but if you lose a critical number the plane will crash. We don't know how many we can lose before the ecosystem crashes."

New Zealand native frogs also appeared to be declining, though they were secretive by nature and therefore difficult to track.

"It is a real concern if there is something happening to our native frogs because they are the most ancient group of amphibians and are very close to the first frogs that evolved," Dr Bishop said.

The frogs had no eardrum and did not croak to communicate. New Zealand was the only place this kind of frog lived.

"We want to try and increase people's awareness of the plight of the frogs and to realise how important they are to the ecosystem and how important New Zealand frogs are to the rest of the world."

Dr Bishop said people should be careful when handling frogs to make sure that if they gathered them from a pond, they returned them to the same pond to avoid transferring diseases.

Frog news.

Pekeketua New Zealand's Native Frogs

What are native frogs?

New Zealand's native frogs belong to the genus Leiopelma, an ancient and primitive group of frogs. The frogs have changed very little in 70 million years. They are small, nocturnal, and are hard to see as they camouflage themselves well. Three of our remaining species live on land in shady, moist forested areas, and one is semi-aquatic, living on stream edges.
Different species

New Zealand originally had seven species of native frog. Three species have become extinct since the arrival of humans and animal pests, like rats, in New Zealand. The four remaining species are:
Hochstetter's frog - the most widespread, it has been sighted around the upper half of the North Island, including at Waipu, Great Barrier Island, the Coromandel, central North Island, and the Raukumara Ranges. It grows up to 48mm long. It has partially webbed feet, more warts than the other frogs, and is generally dark brown.

Hochstetter's frog - Leiopelma hochstetteri
Archey's frog - is found only in the Coromandel and in one site west of Te Kuiti. It is the smallest native frog, growing up to 37mm long. It lives in misty, moist areas around 400m in altitude.

Archey's frog - Leiopelma archeyi
Hamilton's frog - one of the world's most endangered frogs, it is found only on Stephens Island in the Cook Strait.

Hamilton's frog - Leiopelma hamiltoni
Maud Island frog - is only found on Maud Island in the Marlborough Sounds. Recently DOC transferred some Maud Island frogs to Motuara Island.
There are also three introduced species of frog in New Zealand. These species are easily distinguished from native frogs because they have loud mating calls and pass through a tadpole stage.
Fight for survival

Frogs are declining everywhere in the world. More than most creatures, frogs are sensitive to disease, pollution, chemical poisons and environmental changes, as they absorb many things through their sensitive skin.
Fossil records show that our native frogs were spread throughout both the North and South Islands several thousand years ago. The four remaining species have declined significantly in range and in numbers over the past one to two thousand years, as land has been cleared of forest and predators have been introduced.
Hamilton's frog is the most critically endangered species, with less than 300 individuals remaining. Fossil records show it was once spread from Waikato to Punakaiki. Now it survives only on Stephens Island, where it is carefully managed by the Department of Conservation. DOC has created a second population of the frogs on the island, enclosed in a predator-proof fence because tuatara occasionally eat frogs.
Frogs are vulnerable to introduced predators such as rats and cats. In late 1999, a sighting of the aggressive Eastern banjo frog in Auckland also raised fears that if this alien invader gets a foothold, it will out-compete native frogs in their habitat.
Native frog facts

New Zealand's native frogs have several distinctive features, which make them very different from frogs elsewhere in the world:

They have no external eardrum.
They have round (not slit) eyes.
They don't croak regularly like most frogs.
They don't have a tadpole stage. The embryo develops inside an egg, and then hatches as an almost fully-formed frog. The young of most species are cared for by their parents - for example, the male Archey's frog may carry his young offspring around on his back.

Recovery plan in action

The Department of Conservation has a Native Frog Recovery Group that coordinates management and research into native frogs to help with their conservation. The impact of 1080 on native frogs has been investigated, methods for frog monitoring and translocation are being developed and improved, and frog distribution and numbers are being documented.
In 1997 three hundred Maud Island frogs were transferred to Motuara Island - the first-ever inter-island translocation of a native frog. To date, this transfer has been successful. Establishing a second population of the frog in another location is insurance against a disaster, such as fire, wiping out a sole surviving population. A separate population of Hamilton's frog has also been established on its home on Stephens Island and is monitored closely by DOC staff.
How you can help

As native frogs are small, well-camouflaged and nocturnal, they are hard to find. The public can assist the Department greatly by reporting any sightings of native frogs. Record carefully the location, the type of habitat (stream edge, forest floor), the time and date you sighted them, and if possible take photographs. Avoid touching the frogs, because you may damage their sensitive skin. If you do touch them, make sure your hands are wet.
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