Energy transfer and female condition in nursing harp seals Phoca groenlandica

• Published in: Ecography
• Main Authors: Stewart, R. E. A., Lavigne, D. M.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 1984
• Subjects: Ecology, Evolution, Behavior and Systematics; Phoca groenlandica
• Online Access: http://dx.doi.org/10.1111/j.1600-0587.1984.tb01120.x; https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fj.1600-0587.1984.tb01120.x; https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1600-0587.1984.tb01120.x

Lactating female harp seals, most with their pups, were collected on the “whelping” ice in the Gulf of St. Lawrence in 1976 and from 1978 to 1980. During lactation females lost weight at an average rate of 3.17±0.52 (SE b ) kg d −1 , for a total energy loss of approximately 250000 kcal. Pups grew at a mean rate of 2.78±0.19 kg d −1 for a gain in production energy of about 194000 kcal. Compared to 1976, adult females sampled in 1978 to 1980 had lower energy reserves at the onset of lactation. Coincidentally there has been a decrease in newborn lengths and girths. Although compensatory growth in weight appears to occur, between‐year differences in newborn lengths persist to weaning. Various reproductive strategies of female harp seals faced with reduced energy stores are discussed.