Ecological Archives C006-045-A5
S. Villegas-Amtmann, L. K. Schwarz, J. L. Sumich, and D. P. Costa. 2015. A bioenergetics model to evaluate demographic consequences of disturbance in marine mammals applied to gray whales. Ecosphere 6:183. http://dx.doi.org/10.1890/es15-00146.1
Appendix E. Lactation costs (calf metabolic rate and calf growth costs).
Lactation costs (calf metabolic rate and calf growth costs)
The increase in girth/length by calves closely mimics (in reverse) the change in girth/length experienced by older gray whales between southward and northward passages by central California. Therefore, the temporal changes observed in lipid content of adults between south and north migrations provides the best available model for estimating the energy equivalent of tissue growth accomplished by calves (Sumich 1986).
Fraction lipid and muscle was based on extracted oil and meat from 26 adult “fat” (mostly late pregnant females) gray whales caught near San Francisco on their southward migration (Rice and Wolman 1971, Sumich 1986). Therefore, fraction protein and calf caloric value at seven months old is: Fprot7mo. = 0.0972 and C7mo. = 100.81 × 103 MJ (95% confidence intervals, 69.5 × 103 – 137.62×103 MJ), respectively.
Literature Cited
Rice, D. W., and A. A. Wolman. 1971. The life history and ecology of the gray whale (Eschrichtius robustus). Special Publication No. 3. American Society of Mammalogists, Washington, D.C., USA.
Sumich, J. L. 1986. Latitudinal distribution, calf growth and metabolism, and reproductive energetics of gray whales, Eschrichtius robustus. Dissertation. Oregon State University, Corvallis, Oregon, USA.