Lactation costs in southern elephant seals at King George Island, South Shetland Islands

• Main Author: Panarello, Hector Osvaldo
• Language: unknown
• Published: 2004
• Subjects: bioenergetics; lactation; parent-offspring interaction; pinniped; reproductive cost; Antarctica; King George Island; South Shetland Islands; elephant; Mirounga leonina; Phocidae; Argentina; Antarc*; Elephant Seals; Southern Elephant Seals
• Online Access: https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_07224060_v27_n5_p266_Carlini; https://hdl.handle.net/20.500.12110/paper_07224060_v27_n5_p266_Carlini

Labelled-water methodology was used to quantify energy costs and energy transfer efficiency in 18 mother-pup pairs of southern elephant seals (Mirounga leonina) during lactation. During the lactation period, mothers lost a mean mass of 227 ± 47 kg. Mass loss included 22% of the protein, 60% of the fat, and 51% of the energy in the mother's body upon arrival. Total body-energy reserves at parturition explained 69% of the variation in the total lactation costs and 50% of the variation in the pup's body energy at weaning. On average, pups retained 48% of the mass, 49% of protein, 53% of fat and 51% of energy lost by their mothers. Greater, fatter females showed a decrease in the efficiency of energy and fat transfer and, at the same time, an increase in the efficiency of protein transfer. This may be due to an increased use of protein as metabolic fuel, as fat demands for milk production increase. There was no evidence that greater total lactation costs influence the ability of mothers to produce a pup in the next breeding season. © Springer-Verlag 2004. Fil:Panarello, H. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina.