Population stability in the endangered Fleay's barred frog (Mixophyes fleayi) and a program for long-term monitoring

Abstract

In the wake of the global decline in amphibians there is a need for long-term population monitoring. Previous research suggested that the endangered Fleay's barred frog (Mixophyes fleayi) had recovered after a severe decline. We aimed to determine whether this recovery has been sustained and to test an example of a monitoring program that could be employed at intervals of five or more years to assess long-term population stability. We conducted capture-mark-recapture five years after the last detailed census at Brindle Creek in Border Ranges National Park, New South Wales. Frogs were captured along a 200m creek transect between September 2013 and February 2014. We used program Mark to estimate demographic parameters of adult Male frogs using two modelling approaches: robust design (RD) and the POPAN formulation of the Jolly-Seber model. Abundance was estimated at 38.2±0.5 (s.e.) (RD) and 46.0±2.7 (POPAN). Abundance in 2008 was estimated at 53.2±10.0 (POPAN) Male frogs. Estimates of apparent monthly survival over our five-month-long study were very high (RD: 1.0±0.0; POPAN: 1.0±0.02). Recapture estimates were also high (RD: 0.40±0.07 to 0.72±0.05 per session; POPAN: 0.84±0.05 per month). These data suggest that the Brindle Creek population has remained relatively stable over a period of ∼10 years.