A tale of two whales

Conservation physiology tools can be difficult to employ in the wild. Here we discuss developments in conservation physiology research of large whales, a taxonomic group that is famously difficult to study with traditional tools. We focus on the North Atlantic right whale (Eubalaena glacialis) and southern right whale (Eubalaena australis), two closely related species that present similar logistical challenges for research, yet differ in population status and conservation pressures. Research has advanced via a suite of creative approaches including photo-identification, visual health assessment, remote methods of assessing body condition, and endocrine research on non-plasma sample types such as faeces, respiratory vapour, and baleen. These efforts have illuminated conservation-relevant physiological questions for both species, such as discrimination of acute from chronic stress, identification of likely causes of mortality, and monitoring causes and consequences of changes in body condition and reproduction.