Rats to find Frogs
Embargoed 1 April 2008
Rats to find Frogs
“Enemies to be come allies” says Minister of Conservation Steve Chadwick announcing initial success at training rats to locate New Zealand’s tiny rare native frogs “Aside from being nocturnal, and extremely well-camouflaged, the frogs are also tiny, easily fitting into a matchbox.”
“It’s a bold move for the Department but the rats have a unique sense of smell and can move through the bush with minimal disturbance” she said “Given the frogs are so small locating them for population monitoring purposes is nothing short of difficult. Volunteers for frog counts are hard to find even though one could be a prince.”
There are only four surviving native frog species. All are nationally threatened, with the rarest, Hamilton’s frog (Leiopelma hamiltoni), numbering less than 300. New Zealand’s native frog species are endemic and belong to the genus Leiopelma. They have some very distinctive features and behaviours such as they make ‘chirping’ sounds, have round eye pupils (not slits) and they do not have webbed feet.
“The Department has successfully used dogs to locate kiwi and skinks” said Ms Chadwick “But dogs are just too big and cause too much disturbance of the bush in this case.”
The programme to train rats began last year. The Department has decided that white rats are best for visual and ease of recovery purposes. Initially normal grey rats were used but they were lost sight of and never recovered. The rats have been trained to freeze when they sense a frog with the reward of food; it also makes them easy to recover.
The Department now has trained four rats, the best one, Maramawhā, has potentially located a new species on Kaikoura Island. It has been given the temporary name Leiopelma “Aperira-ano” until confirmed a Department spokesperson said. It is sheer coincidence that in the Chinese year of the rat and the international year of the frog these two species are working together.