Reproductive Behavior and Maternal Investment of Australian Sea Lions

摘要: Author(s): Higgins, Lesley V. | Abstract: The breeding cycle, behavior, female attendance cycles and pup growth of Australian sea lions were studied at Kangaroo Island, South Australia, during December to May, 1986-87, April October,1988, November March 1989-90. Animals identified using paint, dye bleach marks each season with tags natural scars between seasons.Females exhibited a synchronized, non-seasonal cycle that is unique for pinnipeds. Data from 191 births gave 527 532 day intervals the median pupping dates three seasons. Sixteen females had mean interval 540 ± 12.0 days (17.7 0.4 months). Comparison timing seasons previous study show seasonal shift 3-4 months 12 year period.Breeding non-gregarious parturition sites spread out in area. As consequence, male territories plastic space time. Tenure on ranged almost continuous occupation less than one week depending whether present. Differential reproductive success males was low. Males usually attended time thus practiced serial polygyny achieve more copulation. Attacks pups by adult territorial accounted 19% mortality two suckled their 15-18 until birth next pup, although 23% did not give consecutively season, continued suckle yearlings up 23 months. Female consisted feeding trips about length stays ashore 1.5 days, nat change over Feeding significantly shorter winter June July may reflect affect. Pup age or sex seemed have no influence cycles. Male heavier grew faster 1988, but 1986-87. Growth rate data older indicate there reduction this always related weaning.