Birth to weaning: parturition, duration of lactation, and attendance cycles of Australian sea lions (Neophoca cinerea)

Abstract

Parturition, time to weaning, and female attendance patterns were studied over four breeding seasons in Australian sea lions, Neophoca cinerea, on Kangaroo Island, South Australia. Females generally exhibited site fidelity in their choice of birth sites, and arrived a mean of 1.8 days prior to birth. After birth, females stayed ashore a mean of 9.8 days before departing on their first foraging trip. Trips to sea were about 48 h in length although there was significant variation over time. Stays ashore were about 33 h long and were much less varied than trips to sea. Females moved pups away from the natal areas after about 1 month, and began spending less time with them while they were ashore. Linked with the extended breeding cycle of 17.6 months was an equally long period of maternal investment. Females suckled their pups for 15 – 18 months, or until about 1 month before the next birth. Twenty-nine percent of females did not pup consecutively each breeding season, but continued to suckle their offspring until the next birth, some for as long as 40 months.