Monitoring the Green and Golden Bell Frog Litoria aurea on the Crookhaven floodplain at Nowra, New South Wales from 2016-2022 and implications for conservation

Abstract

ABSTRACT Systematic (time constrained) and targeted surveys were conducted for the Green and Golden Bell Frog Litoria aurea from 2016-2022 on the Crookhaven River - Shoalhaven River floodplains, on the south coast of New South Wales. Systematic nocturnal surveys were conducted at 30-34 sites, three to four times between October and March. Litoria aurea were observed at 20 sites and males were heard calling at five of these. The majority of detections during the breeding season (January - February) were in flooded areas of Terara Swamp and Brundee Swamp, while outside the breeding season more frogs were seen in the catchment of Rotten Creek, the largest tributary of Brundee Swamp. Ten of the systematic sites were ponds constructed for the species as offsets for various developments. Breeding activity (calling males) was detected at two of these offset ponds, but no tadpoles or juveniles were found. The number of frogs detected during systematic surveys varied from eight to forty-four per season, while the number found during diurnal surveys of 136-175 sites annually ranged from zero to thirty-three. Although recruitment occurred in most years the population did not recover to that previously found in 2010-2012. The lack of recovery was influenced by drought, wildfire and a continual loss of habitat from urban developments. Large adult females were seen each survey beside Rotten Creek or nearby ponds suggesting the adult population overwinters within the catchment of this creek and disperse down this catchment to Brundee Swamp to breed in spring. The results from six years monitoring indicate the Crookhaven L. aurea population has not recovered in abundance and distribution since 2010-2012. The three most abundant species of frog Litoria fallax, Litoria peroni and Limnodynastes peroni were also analysed for site preference and population variations over the survey.