SummaryZotier, R. (1990). Breeding ecology of a subantarctic winter breeder: the Grey PetrelProcellaria cinereaon Kerguelen Islands.Emu90, 180–184.The breeding ecology of the little known, winter breeding, Grey PetrelProcellaria cinereawas studied on the Kerguelen Archipelago. Adults returned to breed in February. The period of egg laying was less extended than has been previously suggested. Laying took place in early April, and hatching in late May to early June. The fledging period, 120 to 160 days, is the longest known among the petrels. The frequency at which chicks were fed affected the length of the fledging period. A particularly long fledging period is common to the southern winter breeders.