Monitoring of Growling Grass Frog populations north of the Great Dividing Range in Victoria is not sufficient to assess long-term population trends. However, there is evidence to suggest the species continues to decline across this region. The species has been lost from the Mitta Mitta valley in north-eastern Victoria sometime over the last decade, with no recent verified (ground truthed) detections east of approximately Kerang in the Murray River Valley in recent years.
In Melbourne, long-term monitoring by project collaborator Dr Geoffrey Heard indicates demonstrates ongoing and extensive declines across northern suburbs. Between the 2001/2002 and 2016/2017 breeding seasons, site occupancy dropped by 28% (G. Heard et al., unpublished data). Surveys being completed at these sites during the 2021/2022 season suggest significant further declines (G. Heard, pers. comm.).
In all, the available evidence suggests Growling Grass Frogs continue to decline across their Victorian range, and that re-introduction programs such as that proposed at Winton Wetlands will be necessary to reverse both historical and recent declines.
This decline is illustrated in the maps below.
- The first pair of maps represent all of the recorded occurrences of L.raniformis in Victoria between 1780-2010 and from 2010-today.
- The second pair represent all of the recorded occurences of L. raniformis across the Northern Victorian region between 1780-2010 and then 2010-today.
These maps were generated using the Atlas of Living Australia data.