We are pleased to announce the recent publication of the
following paper on body shape of free-swimming right whales.
The paper is available online and Open Access from:
Carolyn A. Miller,
Peter B. Best, Wayne L. Perryman, Mark F. Baumgartner,
Michael J. Moore. 2012 Body shape changes associated with reproductive status,
nutritive condition and growth in right whales Eubalaena
glacialis and E. australis
Marine Ecology Progress Series 459:135-156 -
doi: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 width-to-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.