I scouted the wetlands and mudflats as part of Birdlife Tasmania’s summer wader count and my observations – or lack of them – confirmed alarming statistics that numbers of migratory shorebirds are in freefall not just in Tasmania but right across Australia’s coasts.
In fact I did not record one visitor from the northern hemisphere but I am happy to report that others were seen in the wetlands survey around Tasmania’s coasts. Not in the vast numbers seen in past years, however.
About 36 species of waders spend the summer months in Australia and New Zealand when their breeding territories in the far north – some within the Arctic Circle – freeze over during the winter months. Twenty of these waders reach Tasmania, at the limit of the migration route, the East Asian-Australasian Flyway.
The members of Birdlife Tasmania have been monitoring both migratory and resident wader numbers for half a century, in a program that has provided the longest and most comprehensive data on migratory shorebird numbers in Australia.
The data makes depressing reading, as did my own survey of the wetlands compared with those carried out by other local birders before my time.
Not only did I fail to find migratory waders on the “patch” assigned to me, a stretch of coastline from Iron Creek at Lewisham to Primrose Sands, but I missed two of the five birds that once were common resident nesters. I couldn’t find red-capped or hooded plovers but black and pied oystercatchers were in good numbers, along with the ubiquitous masked lapwing, or plover as it is known in Tasmania.
Regarding the migrants, they are all recording serious decreases in numbers.
Most alarming is the demise of the eastern curlew, the biggest of the waders with classic long, curved bill. This once common bird – shot for the pot in past times – is showing a 90 per cent decrease, and there are very real fears that it might be lost to Tasmanian shores forever.
Another of the once common waders, the curlew sandpiper, is already not showing up on the summer bird counts. In the late 1980s, nearly 2000 were being counted in Tasmania.
Across Australia, millions of Australia’s migratory shorebirds are being pushed closer to extinction as the quality of their primary feeding grounds, or ‘‘refuelling areas’’, in East Asia continue to decline.
New research has declared the main refuelling areas in the Yellow Sea at risk of total collapse as coastal development and widespread pollution continue to affect the Yellow Sea’s tidal flat ecosystem.
Apart from losing their main refuelling areas, shorebirds also risk running out of food in the remaining tidal flats, says Dr Richard Fuller of the National Environmental Science Program, who conducted the survey with the University of Queensland.
“Each year, millions of shorebirds migrate between Australia and Arctic Russia, where they breed,” Dr Fuller says. “They fly through the East Asian-Australasian Flyway, stopping in China, Korea and other East Asian countries to rest and feed.
“Twenty seven sites in the Yellow Sea tidal flats are used by forty per cent of shorebirds that migrate through this route. This is an enormous area that fringes more than 4000 kilometres of the coastlines of China, North Korea and South Korea – if you stand on the coastline, there are tidal flats as far as the eye can see.”
Two thirds of the tidal flats have already been destroyed in the name of progress.
Along with pressure on their migration routes, migrants are also facing disturbance in their Australian and New Zealand feeding grounds because of development.
This also affects the local nesting species. The hooded plover is listed as a threatened species nation-wide and in Tasmania the red-capped plover is down 50 per cent in numbers. Other beach nesters, like pied and black oystercatchers, are also under threat across the state.