Fire has shaped much of the Australian landscape, and alterations to natural or historical fire regimes are implicated in the decline of many native mammal species. Time since fire (TSF) is a common metric used to understand vegetation and faunal responses to fire but is unlikely to capture the complexity of successional changes following fire. The New Holland mouse (Pseudomys novaehollandiae), a threatened and declining rodent species native to southeastern Australia, traditionally is considered an early post-fire successional species. Here, we use a 48-year dataset to test whether this posited association with early TSF is upheld, and whether the species' occurrence and abundance are governed by TSF. We find support for a minimal influence of TSF on the species' occurrence, and that while abundance of P. novaehollandiae is explained partly by TSF, considerable uncertainty and variation among fire events and locations limit the usefulness of TSF in informing conservation management strategies. We suggest that it is not helpful to consider the species as early successional and that fire planning for P. novaehollandiae conservation is best considered at a local scale. In addition, we provide guidelines for maximizing individual survival and persistence during and after planned burns.