(click on images to view full screen versions)
		Bird populations on the islands fluctuate seasonally and are primarily made up of migratory species which use the islands as stopovers. These include northern hemisphere species such as plovers, curlews, sandpipers, stints and waders, which over-winter in Australia. Waterbirds which breed in Cape York also travel through the islands on their annual pilgrimage from PNG and parts of Asia. These include Herons, Egrets, Magpie Geese and Wandering Whistle Ducks.
	Migratory Birds and Disease A report commissioned for the Australian Quarantine Inspection Service (AQIS) recently, shows that 46% of bird species in the region are shared between either side of Torres Strait and have, or still do cross the Strait. The percentage is close to 100% for estuarine- and marine-inhabiting birds and as low as 20% for forest birds. For freshwater birds the value is 68%. Very few species en route target the Torres Strait as a place to stay in numbers, in either the wet season or the dry season. Freshwater habitat is not a major feature of the Torres Strait islands. The report continues: There is speculation that migratory birds and/or wind-blown mosquitoes could have brought the first incursion of Japanese Encephalitis to the outer Torres Strait islands in March 1995, from a focus of viral activity, possibly in Papua New Guinea. Birds using the extensive wetlands of the Middle Fly-Lake Murray area of PNG may have transported JE virus from this region to Torres Strait or alternatively, in the other direction. Overseas studies on wild bird hosts of JE have highlighted ardeids as a significant group, particularly the Rufous Night Heron, which is closely related to the Black-Crowned Night Heron. The studies found that the Rufous Night Heron developed sufficient JE viraemia to infect the typical Asian mosquito vector Culex Tritaeniorhynchus. There is no direct evidence that the birds are hosts to JE, but it is highly likely. There are breeding colonies of the Rufous Night Heron on Ker and Deliverance Islands in Torres strait and other colonies down the west coast of Cape York. Several other species move between areas of the Middle Fly River in PNG to the western side of Cape York peninsula to breed every year in the wet season. They include: Great and Intermediate Egrets (identified in Asia as hosts) and Pied and Rufous Night Herons, all of which are common birds of Cape York peninsula. Ducks are also under suspicion as hosts to JE. The species that appear to migrate in greatest numbers are Magpie Geese and Wandering Whistle Duck. Others under suspicion, moving annually between PNG and Australia include the Green Pygmy Goose, Pacific Black Duck and Radjah Shelduck.

	Introduction | Map | In Brief | Inhabitants | Links | Gallery | Behind the Scenes | Credits
	The Series | About islands | Links | Feedback | Site map | Island Life home Lizard | Christmas | Barrow | Kangaroo | Torres Strait | Macquarie © 2010 ABC | Privacy Policy