Monitoring programs are most successful when they undertake regular evaluation of their data to determine if the goals of the programs are achievable and allow changes to achieve this as necessary - so called adaptive management. We use data from a monitoring program for the northern corroboree frog (Pseudophryne pengilleyi), a declining species in south-eastern Australia, to determine the inter-annual variability in the counts and assess what levels of population change would be detectable using different statistical and monitoring approaches. The existing monitoring program would only successfully statistically detect a 3% annual decline (34% total decline) in population size over a ten year period. Monitoring 40 sites would allow an 80% or greater chance of detecting a 2% or greater annual increase over a ten year period (22% increase). Detecting population decreases is more difficult as monitoring 40 sites with a 2% annual decline (19% total decline) will have only a 65% chance of being detected after 10 years. A larger monitoring program is required to detect smaller annual changes in the population of this species. These findings have implications for the likely effectiveness of other anuran monitoring programs as the northern corroboree frog appears to be far more consistent in detectable call effort compared to most species.