Ways to measure body temperature in the field

Area of Science:

• Ecophysiology
• Animal physiology
• Biotelemetry

Background:

• Body temperature (Tb) is crucial for understanding energy saving strategies in ecophysiological studies.
• Accurate Tb measurement in small heterothermic mammals is essential for field research.

Purpose of the Study:

• To comparatively evaluate the field utility of temperature-sensitive passive transponders (LifeChips, IPTT-300) and a data logger (iButton).
• To assess the accuracy and reliability of these devices for measuring Tb in edible dormice (Glis glis).

Main Methods:

• Accuracy testing of LifeChips, IPTT-300, and iButtons in a water bath (0–40°C).
• Field evaluation using subcutaneously implanted transponders and collar-mounted data loggers in 14 male edible dormice each.
• Simultaneous recording of Tb and oxygen consumption in one individual.

Main Results:

• LifeChips showed high accuracy (0.07±0.12°C) within 25–40°C.
• IPTT-300 accuracy decreased significantly below 30°C, requiring individual calibration.
• iButtons demonstrated good accuracy (0.12±0.25°C) across 0–40°C.
• Both LifeChips and iButtons reliably measured Tb in field conditions, with closely correlated readings.

Conclusions:

• Implanted temperature-sensitive transponders are appropriate and minimally invasive for field Tb measurements.
• Data loggers (iButtons) also provide reliable Tb data under field conditions.
• These methods support ecophysiological studies on energy saving strategies in small mammals.