We are happy to share our new publication looking at lung function in a number of cetaceans. We investigated lung function in 2 false killer whales and a juvenile beluga and compared these against previously published data. These data provide comparative estimates for tidal volume, respiratory frequency, and flow in a range of cetacean species. These data show that tidal volume in cetaceans is greater while breathing frequency is lower as compared with terrestrial mammals. However, tidal volume is only about 30% of total lung capacity, much smaller than most past studies have assumed.

Abstract: In the current study we used breath-by-breath respirometry to evaluate respiratory physiology under voluntary control in a male beluga calf (Delphinapterus leucas, body mass range [M_b]: 151-175 kg), an adult female (estimated M_b = 500-550kg) and a juvenile male (M_b = 279kg) false killer whale (Pseudorca crassidens) housed in managed care. Our results suggest that the measured breathing frequency (f_R) is lower, while tidal volume (V_T) is significantly greater as compared with allometric predictions from terrestrial mammals. Including previously published data from adult bottlenose dolphin (Tursiops truncatus) beluga, harbour porpoise (Phocoena phocoena), killer whale (Orcinus orca), pilot (Globicephala scammoni), and gray whale (Eschrichtius robustus) show that the allometric mass-exponents for V_T and f_R are similar to that for terrestrial mammals (V_T: 1.00, f_R: -0.20). In addition, our results suggest an allometric relationship for respiratory flow, with a mass-exponent between 0.63-0.70, and where the expiratory flow was an average 30% higher as compared with inspiratory flow. These data provide enhanced understanding of the respiratory physiology of cetaceans and are useful to provide proxies of lung function to better understand lung health or physiological limitations.