Scientists have been unable to find any evidence of frog breeding at monitoring sites in the Macquarie Marshes during surveys in late 2019.
While 6 species of frogs were found, no sign of breeding or recruitment was detected during the spring survey period.
The Department of Planning Industry and Environment conducts frog surveys at monitoring sites throughout the Macquarie Marshes and has done so each spring since 2014.
Environmental scientist Dr Amelia Walcott said surveys during dry conditions provided important data for comparison.
'No frog breeding activity was detected in our spring 2019 surveys and is not likely to occur until flows return to the Marshes to inundate suitable wetland habitat,' Dr Walcott said.
'All the wetland sites that we routinely monitor were dry during this year's spring surveys.
'In previous years we had seen comparatively widespread and high levels of frog breeding in response to wetland inundation caused by river flows.
'These flows, which included water for the environment and tributary flows, are likely to have played an important role in sustaining frog populations.
'As the drought continues, it is possible that frog populations will decline.
'Some frog species are more tolerant of dry conditions than others and will be able to respond when rains return.
'For others, it may take longer,' she said.
Of the 6 frog species detected during last year's surveys, four were flow responsive species, but their numbers were very low. These frogs rely on flows in the wetlands to breed.
Note: the photographs below are file photos. They were not taken during this survey.
