Ludwig, J. P. 1964 minutes always returning to the same nest sight, and calling loudly each time it arrived on the nest sight. As far as I could tell no bird which engaged in this behavior was mated: 4 individuals were seen to do this. Flying with nesting material could serve as an advertising function also. Nest relief was noted twice. Both times the relieving or incoming bird arrived in a very excited state calling very loudly: one bird landed on the back of its mate, one bird landed on the rim of the nest. In both cases the arriving bird sat on the egg the moment the sitting bird rose to preen, or change position. Throughout this procedure both birds called with the same reedy gurgle, but the arriving bird always more intensely. In one case the relief took 2 minutes, once 6-7 minutes. General Colony Behavior: At 1600 the general appearance of the colony was very quiet. By 1800 there were more birds active and from then until 1850 the amount of noise and number of birds aloft was both high. Apparently this was due to 2 factors - 1) Birds settling on their normal night roost, and 2) Birds arriving in numbers from the sea. Once at 1831 I counted 62 birds in the air, most on short roost to roost hops. The Mokapu Point Colony is divided into a number of roosts - several are large trees in which 8-50 birds roost, three are stands of trees which accomodate up to 135+ birds; and two roosts are on pockets of trees jutting out of the steep cliff-like walls of the area.