The southern blossom bat (Syconycteris australis) is a small (∼18 g), solitary, tree roosting pteropodid, which forages on nectar, pollen, and small fruits. In Australia, the distribution of S. australis extends along the eastern coast from the tropics to subtropical northern New South Wales (NSW). In NSW, Banksia spp. are an important food source for the species. S. australis can lower metabolic rate (MR) and body temperature (Tb) in a controlled manner to save energy and combat short-term food shortage. While it is known that in S. australis torpor use may vary by season, specifically how ambient temperature (Ta) and food availability influence torpor induction is not understood. Our study therefore aimed to provide the first quantitative examination of the relationships between food availability/restriction, Ta, Tb, and energy expenditure in captive male S. australis. To this end, the relationship between Ta (17–37 °C) and diet (‘fed’/‘unfed’) to subcutaneous temperature (Tsub) and MR was examined using flow-through respirometry (in S. australis Tsub is normally within 0.6 °C of Tb). At Ta < 25 °C, mean resting MR and Tsub were consistently lower in ‘unfed’ compared with ‘fed’ S. australis. Below the thermoneutral zone (i.e. below Ta ∼30 °C), the effect of Ta on Tsub depended on food availability, with Tsub decreasing at 0.25 × Ta in ‘unfed’ bats but at only 0.05 × Ta in ‘fed’ bats. In contrast, above the thermoneutral zone, Tsub rapidly increased with Ta regardless of feeding treatment (at 0.9 × Ta in ‘fed’ and 1.0 × Ta in ‘unfed’ bats). The results demonstrate that under a mild thermal challenge, food availability, rather than Ta, is fundamenTal in determining whether S. australis reduces MR and Tb. The ability for regulated Tb reductions in response to food restriction is likely crucial for survival of S. australis.