Threats to frogs
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.
Frogs are vulnerable to predators such
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.