The frillneck lizard (Chlamydosaurus kingii) is a conspicuous and high-profile animal of forests and woodlands throughout northern Australia. In order to cope with the long dry season, the lizards reduce their metabolic rate by 70% and can spend as long as three months sitting in the same tree.

Research on the species at Kapalga revealed a clear short-term response to dry season fires. Frillneck lizards increased the volume of food in their stomach immediately after fires, especially after Late fires. There was a strong preference for remaining in burnt habitat. On the down-side, Late fires were responsible for 30% direct mortality of frillneck lizards, whereas Early fires caused no mortality.

Over longer time periods, there were fewer differences among populations exposed to the different fire regimes. Diet, home range and growth of individuals were similar among Early, Late and Unburnt populations.

The major difference was the area that remained unburnt for a number of years becomes unsuitable for the species, and net migration out of these areas resulted in very low population densities.

Using the information gathered at Kapalga, a simulation model was run on the viability of frillneck lizard population under a range of fire intensities and frequencies. Early fires, even on an annual basis, pose no real threat to the persistence of frillneck populations. Late fires occurring at a frequency of greater than two years in the same population greatly increase the risk of local extinction. Essentially, at this fire frequency the number of animals killed by fire cannot be matched by the level of reproduction and immigration. Habitat unburnt for periods longer than 20 years also become unsuitable for the species.

The frillneck lizard is able to benefit from dry season fires because burning improves access to food resources at a time of the year when food availability is at its lowest. However, either a high frequency of Late fires, or long-term fire exclusion, results in population decline.