Spotted Tree Frog - Conservation Context

CONSERVATION BACKGROUND

Spotted Tree Frogs occur in rocky stream-side habitat in steeply dissected country or gorges with many rapids and waterfalls.  Populations have therefore always been patchily distributed.  Females lay 200-1,000 eggs in narrow spaces beneath large river stones within streams.

All of the remaining Spotted Tree Frog populations are considered vulnerable to extinction from various threats. Some populations are relatively stable while others are declining, and several are on the brink of extinction.

CONSERVATION STATUS

IUCN Red List of Threatened Species – Critically Endangered
Environment Protection and Biodiversity Conservation Act 1999 (Federal) – Endangered
Flora and Fauna Guarantee Act 1988 (Victoria) – Threatened
DSE Advisory List of Threatened Vertebrate Fauna in Victoria - Critically Endangered

Several factors are thought to have contributed to the decline of the Spotted Tree Frog: 

  • Introduced trout occur in all catchments it occupies.  Trout prey on Spotted Tree Frog tadpoles
  • Habitat disturbance from forest management, road works, recreational activities in mountain catchments (e.g trail bikes and 4WD vehicles) contributes to increased erosion, sedimentation of streams, damage to riparian habitat and weed invasion. The extensive bushfires of 2003, 2006 and 2010 may have also disturbed Spotted Tree Frog habitat
  • Chytridiomycosis (caused by Amphibian Chytrid Fungus) infects the frogs’ skin, causing damage to the keratin layer, and death.  Chytridiomycosis is thought to be responsible for many amphibian declines in Australia and around the world in recent years.

Because the remaining populations are small and isolated, they are also subject to stochastic events (e.g. wildfire) that could cause the extinction of the whole population.

RECOVERY PROGRAM

The long term aim of the Spotted Tree Frog Recovery Program is to secure the Spotted Tree Frog from the threat of extinction.

The specific objectives of the recovery plan are to:

  • Address known or predicted threats to the Spotted Tree Frog
  • Ensure that no more Spotted Tree Frog populations become extinct
  • Increase our understanding of Spotted Tree Frog biology and ecology, and potentially threatening processes that may be detrimentally affecting the species, in order to better manage the species and its habitat, and to mitigate threats to the species
  • Ensure that land use activities will not impinge on the survival of the Spotted Tree Frog
  • Encourage community awareness and support for Spotted Tree Frog conservation

These objectives will be acheived by focusing on:

  • Population monitoring to assess the ongoing status of populations and gain knowledge of the population dynamics of the species
  • Captive breeding programs to trial re-introduction at sites where the species has become extinct, and to provide insurance backup for wild populations
  • Research and evaluation of potential causes of decline
  • Habitat protection and management of catchments with respect to other land use practices, weed and fire management

CONSERVATION PARTNERS

The Spotted Tree Frog Recovery Program includes representatives from: