Bird-watchers have been searching Tasmania’s wetlands for a little winter visitor from New Zealand which bucks the trend of north-south migration.
The shorebird, the double-banded plover, chooses to travel east to west, leaving its breeding grounds in the southern New Zealand alps for the south-eastern Australian mainland and Tasmania in March. After its western sojourn, it flies back in early September.
Although the north-south migrants make epic journeys each year of about 13,000 kilometres, the double-banded plovers have a shorter journey, of about 1600 kilometres – still an amazing feat for birds measuring only 20 centimetres.
As part of ongoing research, the plovers have had coloured rubber bands attached to their legs at several sites in New Zealand and local bird-watchers have been keen to spot them in their wintering grounds around Tasmania’s coastline.
Three with bands have already been seen in Tasmania, plus a further two along the coast of New South Wales. The Tasmanian birds were spotted at Marion Bay, South Arm and Boobyalla in the north-east.
The migrant is the most common small plover of New Zealand seashores, estuaries and riverbeds. Although their plumage varies seasonally, they are readily identified by their brown upperparts and a complete or partial chestnut breast band, the latter striking in breeding plumage. Like other typical plovers, the body is held erect and they have a characteristic run-stop-peck-run foraging behaviour in their pursuit of small invertebrates.
Not all of these plovers visit Australia. There is an estimated population of 50,000 double-banded plovers in New Zealand and about half are thought to migrate. Much has been learned about them over the years through bird banding. Birds of the mountainous inland areas of the South Island tend to migrate to the coast or fly to Australia. Coastal birds are sedentary.
Winter is not normally an exciting time for shorebird watching because the majority of migratory species are in their breeding grounds in the northern hemisphere. The chance of spotting double-banded plovers, however, makes a winter outing worthwhile and there is always the chance of spotting northern shorebirds – possibly young birds – that have stayed for winter.
The group of shorebirds also known as waders are among the most threatened in the world, primarily because the wetlands they use as feeding stops on their epic journeys are rapidly being drained and developed. Because the double-banded plovers do not use the north-south flyway through Asia they escape these pressures and the population of these birds is holding its own.
The plovers in Tasmania may be in their dull non-breeding plumage but at the end of winter it is possible to see birds which have attained their summer livery as they prepare to depart.
So far this winter I have failed on my plover quest but I am reassured by the reported sightings the birds are still finding a winter haven on this side of the “ditch”