Use of videos to measure dynamic body acceleration as a proxy for metabolic costs in coral reef damselfish (Chromis viridis).

Quantifying the energy costs of various activities is critical to understand key aspects of animal behavior and ecology. Currently, calorimetry is the most widely used method to measure those costs in laboratory studies, whereas field studies use the doubly labeled water method, heart rate and dynamic body acceleration (DBA). However, these methods are limited or even biased because of restricted space for movement, low temporal resolution and/or the need for logger attachment or implantation. Measuring energy costs of behaviors is difficult, especially in small, highly mobile animals. Here, using a damselfish, Chromis viridis, we demonstrate that DBA, obtained from marker-less, automatic video tracking and 3D reconstruction, can effectively estimate oxygen consumption rate. We show that our video-based DBA method can be used to estimate metabolic costs of various activities, such as locomotion and feeding, on an individual basis.