Waterbird surveys of the Middle Fly River floodplain, Papua New Guinea

In total, 58 species of waterbird were recorded on the grassed floodplain of the Middle Fly during surveys in December 1994 and April 1995. The floodplain is an important dry-season habitat both in New Guinea and internationally, with an estimated (+/- s.e.) 587249 +/- 62741 waterbirds in December. Numbers decreased 10-fold between December and April to 54914 +/- 9790: the area was less important during the wet season when it was more deeply inundated. Only magpie geese, comb-crested jacanas and spotted whistling-ducks were recorded breeding on the floodplain. The waterbird community was numerically dominated by fish-eating species, especially in December. Substantial proportions of the populations of many species that occurred on the Middle Fly in December were probably dry-season migrants from Australia, suggesting that migration across Torres Strait is important to the maintenance of waterbird numbers in both New Guinea and Australia.