The Frog Crisis

Nearly 1 in 3 Amphibian Species is faced with extinction.
As many as 168 species may be extinct.

The global crisis faced by frogs has continued to worsen since identified in the early 1980s. The Global Amphibian Assessment (GAA) (IUCN 2005), the first comprehensive study over a three year period completed in 2004, found that nearly one-third (32%) of the world’s amphibian species are threatened, representing 1,856 species.

As many as 168 amphibian species may already be extinct. At least 34 amphibian species are known to be extinct, while at least another 113 species have not been found in recent years and are possibly extinct. At least 43% of all species are declining in population, indicating that the number of threatened species can be expected to rise in the future. In contrast, less than one percent of species show population increases.

The need to focus on disciplined attempts to establish protocols for captive frog husbandry and breeding is highlighted by a survey indicating that, despite 70% of Australian frog species having been held in captivity, less than 20% have been bred and these mostly represented species with few if any unusual lifestyle characteristics (Marantelli, 1999). It is apparent that only a small number of species of frogs have been studied extensively in captivity.

Australia has recently lost two frog species (to extinction) due to Chytrid fungus and currently 52% of the remaining Australian threatened frog species are infected with this disease (Department of Environment and Heritage, 2004).

Habitat Destruction

Habitat destruction and alteration are having a serious effect on amphibians. Without suitable homes, they cannot survive. Amphibians are also good indicators of environmental health. If the air and water are polluted, frogs are usually the first to feel it…and die of it.

Chytrid Fungus

52% of threatened Australian frog species are infected with a deadly disease caused by Chytrid fungus. The fungus attacks the keratin in the top layer of a frog’s skin. As frogs drink and breathe through their skin, it is thought the fungus may be killing frogs by disrupting these mechanisms so the frogs suffocate or die of dehydration. The fungus may also release a toxin. Chytrid fungus is highly contagious and spreads easily and quickly through soil and water.

Introduced Species

Introduced species such as Gambusia (Mosquito fish) and Cane Toads have had a devastating effect on the Australian environment and its native animals. Gambusia devour frog eggs, impacting on their numbers, while the Cane Toad competes with native animals for food, eats nearly anything that can fit in its mouth and is highly toxic if eaten.