Development and validation of an implantable sensor for measuring activity and body temperature for long-term studies in small wild and laboratory animals

ABSTRACT In the present study, accelerometer data obtained from a sensor prototype and data obtained from commercial animal-activity recording systems were recorded simultaneously and processed to identify the parameters most fully describing the locomotor activity of laboratory mice. A linear combination of the found parameters explained up to 66% of the variance of activity measured by the PhenoMaster system and up to 86% of the variance of activity measured by the LABORAS system, with 20-min averaging of the parameters measured every minute. Correlation coefficient between body temperature and activity measured by the prototype was higher than that for activity measured by the PhenoMaster system. It has been demonstrated that the developed sensor can be used to assess an animal’s locomotor activity at least with 20-min averages, and when powered by a 5 mAh battery with a total sensor weight of 0.9 g, the resulting runtime is expected to exceed 6 months effectively making it a data logger suitable for long-term field research.