Each year birdwatchers in Tasmania set out to monitor populations of migratory shorebirds – and each year they record staggering declines in numbers of these remarkable birds.
BirdLife Tasmania has in fact the longest data sets of shorebird numbers stretching back more than 40 years. These figures make sobering reading.
One species of the group of birds commonly called waders, the curlew sandpiper, is hardly ever recorded in Tasmania these days, after being counted in the thousands just a few years ago. And another, the eastern curlew, has decreased by 95 percent and is now listed as critically endangered.
There are, in fact, two wader counts in Tasmania, at the height of summer when the migratory wading birds have arrived from their breeding grounds in the northern hemisphere, and another in winter. The latter is designed to record what waders might be overwintering in Tasmania – mainly juveniles – and numbers of the non-migratory species like pied and sooty oystercatchers.
As usual in mid-July I took telescope, binoculars and pen and paper to the coastline around Dodges Ferry to play my part in the bird winter census which covers all of Tasmania’s mudflats and wetlands.
I wasn’t that hopeful of seeing eastern curlews – the biggest and most dramatic wader standing 66 cm tall, with an impossibly long down-curved bill – which are rare in winter at the best of times.
The curlews once flew in such great number across southern Tasmania in summer that they were shot for the pot in their thousands around Sorrell.
The decline in migratory shorebirds is largely attributed to vanishing wetlands along their migratory route, the Australasian-East Asia Flyway, which crosses some of the most densely-populated areas of the world where massive land reclamation schemes have taken place, particularly around the shores of the Yellow Sea.
Another threat to the waders is the draining of wetlands along the coast of Australia itself.
As the great northern migration was getting underway earlier in the year, conservationists lost the first round of a fight to halt a proposed development at a vital feeding ground in Queensland.
BirdLife Australia, of which the Tasmanian group is an affiliate, has long campaigned against the port and marina development at Toondah Harbour in Moreton Bay but federal Minister for the Environment Josh Frydenberg announced he was allowing the proponents, the Walker Group, to carry out an environmental impact assessment.
BirdLife Australia has in the past pointed out that Moreton Bay embraces wetlands which have international conservation status, falling under the United Nations-backed Ramsar convention on wetlands adopted in the Iranian city of the same name in 1971.
The ornithological organisation remains hopeful the Walker Group plan will be rejected for the same environmental reasons that scuttled its controversial proposal for a marina on Ralphs Bay in the Derwent some years back. Conservationists had pointed out the bay off Lauderdale was vital to not only shorebirds but endemic marine life.
Meantime, BirdLife Tasmania members are assessing the results of the summer and winter surveys and so far they do not make happy reading.