ODBA_explained

Overall Dynamic Body Acceleration (ODBA) measures an animal’s physical activity. It can be used to study a variety of behaviours, including foraging, hunting, mating and incubating (behavioural studies). It can also estimate the amount of energy an animal is expending to move around and perform various behaviours (physiological studies), e.g., Oxygen consumption of study species in relation to the activity level.

ODBA is calculated based on acceleration data collected from the accelerometer of the transmitters. By summing the absolute values of the dynamic acceleration from all three spatial axes (surge, heave, and sway). The dynamic acceleration is obtained by subtracting the static acceleration from the raw acceleration signal. The static acceleration represents the gravitational force that is present even when the animal is not moving. In contrast, the dynamic acceleration represents the acceleration due to the animal’s movement.

Figure. The derivation of ODBA from the raw acceleration data.

ODBA is measured in units of g, representing the acceleration due to gravity. A higher ODBA value indicates that the animal is more active, while a lower value indicates less activity.

ODBA is a useful tool for studying animal behaviour and can provide insights into how animals use their habitat, how they interact with each other, and how they respond to environmental changes.

References

Halsey, L.G., Green, A.J., Wilson, R., Frappell, P.B., 2009. Accelerometry to estimate energy expenditure during activity: best practice with data loggers. Physiol. Biochem. Zool. 82, 396–404.

Halsey, L.G., Shepard, E.L. and Wilson, R.P., 2011. Assessing the development and application of the accelerometry technique for estimating energy expenditure. Comp. Biochem. Physiol. Part A Mol. Integr. Physiol. 158, 305-314.

Shepard, E., Wilson, R., Albareda, D., Gleiss, A., Gomez Laich, A., Halsey, L.G., Liebsch, N., Macdonald, D., Morgan, D., Myers, A., Newman, C., Quintana, F., 2008. Identification of animal movement using tri-axial accelerometry. Endang. Species Res. 10, 47–60.

Shepard, E., Wilson, R., Halsey, L.G., Quintana, F., Gomez Laich, A., Gleiss, A., Liebsch, N., Myers, A., Norman, B., 2008. Derivation of body motion via appropriate smoothing of acceleration data. Aquat. Biol. 4, 235–241.