Geocrinia alba

Geocrinia albaSpecies name: Geocrinia alba

Common name: White-bellied Frog

Red List status: Critically Endangered (http://www.iucnredlist.org/apps/redlist/details/9031/0)

Distribution: South-west Western Australia: north and west of the Blackwood River between Margaret River and Augusta (it has been recorded in Leeuwin-Naturaliste National Park, and in Forest Grove and Witchcliffe State Forests).

Habitat: Swampy flows along drainage depressions in the coastal zone, characterised by high rainfall and usually associated with sandy soils, a dense ground layer of rhizomatous vegetation and dense over-storey vegetation.

Threats to survival: Habitat clearing, habitat disturbance, including grazing and damage by feral pigs, inappropriate fire regimes, alterations in hydrology (natural and anthropogenic), decreased water quality resulting from contamination of surface and ground water by herbicides, pesticides, fertilisers, etc., spray drift of agricultural chemicals directly into occupied areas, disease (amphibian chytrid fungus).

Reproductive behaviour: Terrestrial breeders that exhibit direct development. Males call from burrows in the substrate (usually under litter, moss, or other vegetation) during spring or early summer, and 10-12 eggs per clutch (on average) are laid in these burrows. There is no parental care. The eggs hatch and larvae develop and metamorphose within the jelly associated with the egg mass, with no free-swimming or feeding stage.

Interesting natural history notes: Geocrinia alba, like G. vitellina, exhibits low fecundity, an extended juvenile period, and highly variable adult survival rates, and therefore is susceptible to both environmental and stochastic catastrophes.

It is also highly sedentary: 95% of adult males included in a study moved less than five metres between seasons within a year, and less than twenty metres between years. This means that there is little potential for dispersal between populations, which has implications for gene flow and the capacity for the natural re-establishment of populations that die out.

In situ projects currently underway: Annual population monitoring, including at the site near Witchcliffe where captive-reared individuals were released in 2010 with the aim of re-establishing a population.

Ex situ programs: The Native Species Breeding Program at Perth Zoo is currently conducting a head-start program with this species (i.e. collecting egg nests from the wild and rearing the individuals through until approximately eight months post-metamorphosis prior to releasing them back into the wild), and is aiming to expand this into a captive breeding program.

How can we help this species? As approximately 75% of the geographic range of G. alba is within private land, people that live in this area can protect the remaining habitat (including excluding fire), and raise awareness of the species locally.

Other links: White-bellied Frog – Department of Sustainability, Environment, Water, population and Communities.