SUCKLING AN ADDITIONAL PUP TO WEANING IN THE NEW ZEALAND FUR SEAL

摘要

In pinnipeds (suborder: Pinnipedia; seals, sea lions, and walrus), the costs of suckling additional offspring are expected to be high with regard to the foraging effort required for additional milk energy production and fasting pressures imposed on both mother and pups (Gemmell 2003, Hoffman and Amos 2005). In all otariid species (fur seals and sea lions), females give birth to a single pup with rare exceptions (Trillmich 1990) and mothers, typically, will only allow their own offspring to suckle (Stirling 1975). From birth, a highly developed recognition system between otariid mother and pup is established, with identification cues between the pair primarily auditory (unique vocalizations) and olfactory (individual scents; Lunn 1992). Non-filial pups attempting to acquire milk resources are usually recognized promptly and warned away by aggressive behavior from mother and/or filial offspring.