Body shape changes associated with reproductive status, nutrituve condition and growth in right whales Eubalaena glacialis and E. australis

• Published in: Marine Ecology Progress Series
• Main Authors: Miller, Carolyn A., Best, Peter B., Perryman, Wayne L., Baumgartner, Mark F., Moore, Michael J.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Inter Research 2012
• Subjects: Right whale; Body shape; Body condition; Aerial photogrammetry; Reproduction; Energetics; Eubalaena; Hussey; Eubalaena glacialis; North Atlantic
• Online Access: http://hdl.handle.net/2263/58465; https://doi.org/10.3354/meps09675

Mammalian reproduction is metabolically regulated; therefore, the endangered status and high variability in reproduction of North Atlantic right whales Eubalaena glacialis necessitate accurate assessments at sea of the nutritional condition of living individuals. Aerial photogrammetry was used to measure dorsal body width at multiple locations along the bodies of free-swimming right whales at different stages of the female reproductive cycle (E. glacialis) and during the initial months of lactation (mother and calf Eubalaena australis) to quantify changes in nutritional condition during energetically demanding events. Principal components analyses indicated that body width was most variable at 60% of the body length from the snout. Thoracic, abdominal and caudal body width of E. australis thinned significantly during the initial months of lactation, especially at 60% of body length from the snout, while their calves’ widths and widthto- length ratios increased. The body shape of E. glacialis that had been lactating for 8 mo was significantly thinner than non-lactating, non-pregnant E. glacialis. Body shape of E. glacialis measured in the eighth month of lactation was significantly thinner than that of E. australis in the first month, but did not differ from that of E. australis in the third and fourth months. Body width was comparable with diameter calculated from girth of carcasses. These results indicate that mother right whales rely on endogenous nutrient reserves to support the considerable energy expenditure during the initial months of lactation; therefore, photogrammetric measurements of body width, particularly at 60% of body length from the snout, are an effective way to quantitatively and remotely assess nutritional condition of living right whales. The National Oceanic and Atmospheric Administration (NOAA), National Marine Fisheries Service, the Northeast Consortium, and the Hussey Foundation through the Ocean Life Institute at Woods Hole Oceanographic Institution. ...