2015-07-172015-07-172015-06Wege, M, Nevoux, M, De Bruyn, PJN & Bester, MN 2015, 'Multi-state mark-recapture models as a novel approach to estimate factors affecting attendance patterns of lactating subantarctic fur seals from Marion Island', Antarctic Science, vol. 27, no. 3, pp. 251-261.0954-1020 (print)1365-2079 (online)10.1017/S0954102014000716http://hdl.handle.net/2263/49101Observer-based studies often underestimate key ecological parameters. Here a fresh approach was used to analyse six years (2006–11) of attendance cycles to estimate foraging trip lengths of a lactating flipper-tagged otariid: subantarctic fur seals at Marion Island. Multi-state mark-recapture models were used to calculate detection failures of females, correct estimates accordingly, and investigate the effects of year, season, pup sex and the presence of a telemetry device on attendance cycle parameters. There were no differences between corrected and uncorrected attendance data. This is attributed to the high capture probability across all seasons (range: 83–98%). This illustrates that observer-based studies are useful to augment telemetry studies. Only season and pup sex had a significant impact on female provisioning rates. In winter, foraging trip durations were longer (t-value = 25.22, P <0.0001) and attendance durations shorter (t-value = -2.15, P = 0.01) than during summer. Females with female pups spent a higher proportion of their time on land (χ2 = 6.6, P < 0.05). Male pups have higher growth demands and are larger which suggests they can deplete female milk-stores faster.en© Antarctic Science Ltd 2014Arctocephalus tropicalisDetection probabilityPup sexSeasonal effectsTransition probabilityPostprint Article