Mortality of eggs and nest attendance pattern of male and female Adélie Penguins were studied in Lützow-Holm Bay, Antarctica. Twenty percent of eggs were deserted by parents and were taken by skuas soon after. Only four percent of eggs were lost from skua predation. In pairs relieving incubation routines successfully (coordinated pairs), females made the first foraging trips of 18.3 days after clutch completion, alternately males made the second trips of 10.6 days. Desertion of eggs and small chicks occurred when 1) females did not return from the first foraging trips and the mates deserted nests, 2) males did not return from the second foraging trips and the mates deserted nests or 3) males went to the first foraging trips. The males whose partners did not return from the first trips did not incubate longer than males of coordinated pairs in the first incubation spell, while females whose partners did not return from the second trips incubated twice as long as those of coordinated pairs.
The Moorhen Gallinula chloropus is a well known intraspecific brood parasite.However, there has been no reports on brood parasitism of the Moorhen in japan. During a 8-yr field study of marsh nesting birds in Akigase marsh, central japan, we found some Moorhen nests which contained abnormally large number of eggs (super-normal clutch) and we obtained evidence of intraspecific brood parasitism and/or cooperative nesting. Moorhens were unable to distinguish between foreign (Japanese Quail and conspecific) and their own eggs. A proximate cause of frequent egg dumping may due to the high breeding density in the habitat. This is the first report on the egg-dumping in a Japanese population of the Moorhen.