Body temperature variation of free-ranging and captive southern brown bandicoots 'Isoodon obesulus' (Marsupialia: Peramelidae)

To investigate patterns of thermoregulation in free-ranging and captive southern brown bandicoots 'Isoodon obesulus', we measured abdominal body temperature (Tb) of five free-ranging bandicoots over 42 days using implanted data loggers and Tb of three captive bandicoots over 3 months using implanted temperature-sensitive radio transmitters. Bandicoots in the wild had a mean Tb of 36.5±1.0 °C (range 33.4-39.8 °C) and showed a pronounced nychthemeral pattern with two distinct temperature phases. Tb increased at 13:30±2.6 h each day and remained high for 10.65±2.07 h, suggesting a crepuscular and early evening activity pattern. Daily Tb variation of 'I. obesulus' would save considerable energy by reducing daytime thermoregulatory costs in the wild. Captive bandicoots had a similar mean body temperature (36.9±0.2 °C) and range (33.0-39.9 °C) as free-ranging bandicoots. However, the nychthemeral Tb pattern of captive bandicoots was different from free-ranging bandicoots, with a less pronounced daily cycle and the nocturnal rise in Tb occurring mainly at sunset and the daily decline occurring mainly at dawn.