Recording body temperature in koalas (Phascolarctos cinereus): a comparison of techniques

Objective: Compare the use of four techniques to measure body temperature in koalas: intraperitoneal (thermal data logger and temperature sensitive radio transmitter), rectal (certified thermometer), tympanic (infrared thermometer), and hind foot (infrared camera).

Methods: The body temperature data collected concurrently from the intraperitoneal loggers were used as the benchmark in the analyses.

Results: The rectal, foot and tympanic methods consistently recorded lower body temperature when compared with the benchmark. There was a strong positive relationship (R² = 0.79) between logger and rectal measurements, but no significant relationship between logger and foot or logger and tympanic measurements.

Conclusion: Rectal measurements can be used to record internal body temperature, with the caveat that such measurements will generally register a temperature approximately 0.25°C lower than the actual intraperitoneal temperature.