K.E. Amerman 1964 Sandie Johnston Mar 24 apparently to get water. We watched many dipping their bills in the lagoon all around the island. It was a very hot, still day. Many of the birds were noted with bills open - equivalent of gular flutter? We also observed changeover in several pairs. In most this was accomplished with ease; the sitting bird merely moved aside when the new one nudged it beneath with its bill, generally from the side. In case the former incubating partner remained nearby and in some instances deported immediately. In one case, one bird gave up the egg and then returned and took it over again in less than 3 min. One pair seemed to be having difficulties. The incubating bird was very reluctant to leave and its partner repeatedly tried to get at the egg, rooting under the other bird and under its wing trying to push the other off. Perhaps changeover had already occurred. I wonder if the very liquid materials given up by some of the birds (from bill and anus) indicate that that bird has been incubating for some time, without solid food.