This study investigated the factors that influence the home-range size of a tropical Australian rodent, 'Melomys cervinipes', using radio-tagged individuals. 'Melomys cervinipes' frequently used the canopy and, when measured according to height level, its home-range areas were much larger than calculated by traditional two-dimensional home-range calculations. Home-range size did not significantly differ between the sexes, with an average home range of 0.42 ± 0.06 ha and core area of activity of 0.091 ± 0.074 ha. 'M. cervinipes' did not maintain exclusive home ranges and overlapped with both other focal individuals and individuals not fitted with tracking devices. There was a relationship between the core range of 'M. cervinipes' and individual trees of the dominant canopy species at the site. Core ranges of 'M. cervinipes' included 2 (1.96 ± 0.27) individual canopy trees independent of the area of that core range, whereas the number of individual trees within their total range was proportional to the size of that range. This suggests that 'M. cervinipes' sets the core of its range to include a specific level of canopy resources regardless of the size required to achieve that level, but that its overall range is merely a representative sample of trees from the site.