EFFECTS OF FOOD AVAILABILITY ON FLEDGING CONDITION AND POSTFLEDGING SURVIVAL IN KING PENGUIN CHICKS

Effects of summer food shortage on king penguin Aptenodytes patagonicu s chicks were studied at South Georgia. Two cohorts were compared, fle dging in the austral summers of 1992 (n = 32) and 1994 (n = 33) when a vailability of food was judged good and poor, respectively. The former cohort had a higher pre-fledging mean mass (12.78 kg vs less than or equal to 10.03 kg), fledged earlier (median 5 January vs 21 January), and a higher proportion was re-sighted within 2 years of hedging (28% vs 0%). Within 4 years, 47% of the former cohort had been re-sighted ( i.e, post-hedge survival); in addition, one was observed at the Falkla nd Islands, and 22% had bred (i.e, recruitment) in their colony of ori gin. The re-sighted chicks of the 1992 cohort fledged earlier than tho se not re-sighted (median 24 December vs 10 January), but it remain un clear if they were heavier at fledging. All chicks in this study (n = 65) were marked with both transponders (subcutaneously implanted) and flipper bands (on one flipper), and no losses of any markings were fou nd (controlled up to 4 years afterwards). Therefore, data on chick pos t-fledging survival and recruitment were not adjusted for losses of ma rkings, as has been done in other studies.