Estimating energy expenditure of sperm whales living in social units.

data with these two methods. The estimated mean daily FMR, including estimated basal metabolic rates (BMR), was 412 MJ/day (95% CI: 262.20-616) using the respiration-based method and 620.5 MJ/day (95% CI: 402-839.3) using ODBA. This study provides the first estimates of daily FMR for sperm whales and revealed that averaged-sized individuals from social units have FMRs between 1.59 and 2.39 times the predicted BMR of similar-sized terrestrial mammals, based on respiration rates and ODBA estimates, respectively. Our findings, combined with data on energy acquisition, can contribute to improving predictions of how environmental stressors impact energy balance, health and the long-term population viability of deep-diving marine mammals.