Northern Corroboree Frog

The northern corroboree frog reaches sexual maturity at three years of age and breeds over a three week period at some point between January and March (4). Between 16 and 40 small eggs are laid which hatch four to six months later, following rains heavy enough to raise ground-water levels and flood the nest. The newly hatched tadpoles are washed into small pools of water where they remain for the next six to eight months. The metamorphosis from tadpole to adult frog takes place between December and early February (1). Adults consume mainly ants. They rarely survive long enough to breed more than once and few of their offspring survive (6).

Much of the habitat occupied by northern corroboree frogs is within reserves, providing protection for the frogs and their habitat. Research into the behaviour, biology and range of the frog is being undertaken and population monitoring is in place (1).

Differing in appearance only slightly from the corroboree frog (Pseudophryne corroboree), the northern corroboree frog has the same distinctive bright yellow and black striped back. However, the stripes are a greener shade of yellow and are also a little narrower (6). The underside has white, black and yellow-green blotches (2). Females are larger than males and, unusually, neither sex has webbed toes. In some areas, 'corroboree' is an aboriginal word for a gathering or meeting – where traditionally the attendees are adorned with yellow markings not unlike those of this rare frog (5).

During the summer breeding season, the northern corroboree frog is found in sphagnum bogs and wet heath in sub-alpine areas, but in dense patches of herbs at lower elevations. Through the winter it is found in the leaf litter of forests, sub-alpine woodlands and tall heaths near the breeding area (1) (2).

Endemic to Australia, the northern corroboree frog is found in the northern Australian Alps of New South Wales and in the Australian Capital Territory (1).

The northern corroboree frog is classified as Endangered (EN B1ab(ii,iv,v) + 2ab(ii,iv,v)) on the IUCN Red List 2004 (1), as Vulnerable on Schedule 2 of the Threatened Species Conservation Act (3) and as Vulnerable under the federal government's Environmental Protection and Biodiversity Conservation (EPBC) Act (4).

The decline of the northern corroboree frog has been monitored with despair, as the exact cause of the drop in numbers, and that of other Australian amphibian species, is not known. Factors thought to be contributing include the detrimental effects of introduced plants such as blackberry (Rubus fruticosus) and monkey musk (Mimulus moschatus), which smother the breeding sites of the frog, as well as the trampling effects of feral pigs and introduced horses (1). Habitat loss, erosion and human disturbance are also thought to have contributed (3). A pathogen called Chytrid fungus has been detected in museum specimens, and is now the major suspect for the cause of the decline (1) (4).