What is a shorebird?
Shorebirds, also known as waders, gather in intertidal areas or on the fringes of freshwater wetlands. They generally have long legs in relation to their body size, no webbing on their feet and they don't swim. The shape and size of their bill gives a clue to their preferred diet and habitat. For example, the long, probing bill of the eastern curlew is ideal for fishing out worms and crustaceans from deep mud, whereas the short, stubby bill of the ruddy turnstone can flip aside stones and shells on a rocky foreshore.
Shorebirds make up about 10 per cent of Australia's species of birds. Fifteen species of shorebird are resident in Australia and an additional 34 species are regular migrants. Most of the migrant species breed in northern China, Mongolia, Siberia and Alaska during June and July and then migrate to Australia for the non-breeding season. Each year, more than a million shorebirds migrate to and from Australia, and many more millions worldwide travel great distances between their breeding and non-breeding habitats. About 40,000 shorebirds of the 34 species migrate to Moreton Bay in Queensland each year.
Some shorebirds weighing as little as 30 grams may migrate 25,000 km annually. Some species may fly more than 6,000 km non-stop. In doing this, they use favourable weather patterns when they can, but even so will commonly lose 40 per cent of their bodyweight, flying at more than 60 km/hr, non-stop for three days and nights. Shorebirds make the journey in several weeks, stopping two or three times along the way. When they stop, they must 'refuel': they feed and rest to build up energy reserves. At these times they may increase their body weight by more than 70 per cent before undertaking the next marathon stage of their journey.
Through wind and storm, enduring unbearably hot days and freezing nights, avoiding waiting hunters, shorebirds miraculously navigate along a precious chain of wetlands, including Moreton Bay, to complete their global journey. Migrating shorebirds travel these remarkable distances each year because of their special breeding requirements. Breeding takes place in areas where melting snow signals masses of insects, providing a vital food source for self-feeding chicks. Once breeding is complete, and before the onset of the Arctic winter, the adults and newly fledged chicks begin their incredible return journey to the plentiful feeding grounds of the south.
One of Queensland's migratory shorebirds, the double-banded plover, follows the same principle, but rather differently. It breeds on the pebble beds of the rivers of New Zealand's South Island in the summer months from September to March, and then flies trans-Tasman to spend the southern winter in the comparatively warm conditions of Australia's east coast. So it arrives in Queensland in March/April when all other migratory shorebirds are leaving for Siberia and Alaska, and leaves in August/September when the others are returning.
Migrating shorebirds need huge amounts of energy to complete this perilous journey. One of the best-studied species, the eastern curlew, dramatically builds up its body weight just before migration. During its flight from Siberia to Australia, it will burn off 40 per cent of this weight to fuel its 13,000 km journey. This is like an 80 kg person running 16 million kilometres almost non-stop and losing 32 kg, twice a year!
Each year about 15 per cent of the migrating shorebirds that visit Moreton Bay in the summer stay for the whole year. These include birds that are too young to breed or adults that are not strong enough for the journey north.
Highways in the sky
The routes that shorebirds travel along on their annual migration are called flyways. A flyway is broadly defined as the migration route of a population, species, or group of species of birds, between a breeding area, through the staging sites and non-breeding area. Flyways are like invisible highways. How does a migrating shorebird know which way to go? Are there maps in the stars? Patterns on the land? Memories in their genes? Or are they guided by the sun and the moon or the earth's magnetic field? Scientists say it is probably a combination of all of these but they are still unclear exactly how migratory shorebirds find their way.
Like weary travelers on a lengthy journey, shorebirds need rest stops along the way to refuel and have a break. Flyways are like chains with many links. Each link is an important wetland, such as an estuary or bay, where the birds can stopover to feed and regain their strength for the next leg of their migration. The message is clear, everything is interconnected — remove enough of these links and species may disappear altogether!
Moreton Bay is an important habitat in the East Asian–Australasian Flyway, which is one of eight flyways in the world. The East Asian–Australasian Shorebird Reserve Network is an international chain of wetlands recognised for their importance to shorebirds. The network ensures there are safe and convenient stopover points for shorebirds to rest and feed along their "endless summer" between the Arctic north and the warm south.
Shorebirds' lives are driven by tides
At low tide, regardless of day or night, shorebirds feed constantly — pecking and probing for worms, insects and crustaceans. With highly variable and specialised bills they feed around intertidal flats, beaches, rocky headlands and along the fringes of freshwater wetlands.
As the incoming tide covers these feeding areas, they begin to congregate in large numbers at relatively safe and nearby roost sites. These roost sites provide areas where they can interact, preen, digest their food and rest while waiting for the ebbing tide to again expose their feeding areas. During particularly high spring tides, all the shorebirds of Moreton Bay crowd together on a limited number of higher elevation roost sites. Disturbance during this time is more damaging than usual.
What else is so special about shorebirds?
There are many special and fascinating things about shorebirds. Being able to fly is something many people dream of, and to be able to travel thousands of kilometres in flight is amazing.
When a flock of shorebirds takes flight on the next leg of its journey, watch how they circle overhead — some will form a beautiful "V" formation in the sky before heading off like a giant arrow.
Some shorebirds have beautiful or haunting calls. Listen for the eerie cry of the bush stone-curlew at night, or the signature call of the eastern curlew during its annual summer stopover.
Other special features of shorebirds include their sleek design, specialised bills for feeding and expert hunting skills. Near the end of summer, many species will moult and change into spectacular breeding plumage — announcing their suitability as potential partners.
In Australia there are Aboriginal stories about shorebirds and in some cases there is evidence of their traditional use. For the Aboriginal people of Moreton Bay the eastern curlew, known as the "sea curlew" — Gurrrell — was a source of food during summer. The "land curlew" (bush stone-curlew), also known as the "messenger bird" — Bullingan — because of its eerie cries, brought a message from Aboriginal spirits to the people. When an Aboriginal person is about to depart this life, the messenger bird visits his home at night and gives three calls.
You can help protect shorebirds
Shorebirds are not like streetwise urban birds such as noisy miners, crows, pigeons or magpies; they are very easily disturbed by close activity. When shorebirds are disturbed they waste hard-earned energy reserves, reducing their ability to survive on their long migration.
Dogs, in particular, disturb shorebirds. In local government areas adjoining Moreton Bay, and on some other areas along the coast of Queensland, dogs must be on a leash at all times unless in a designated "off leash" area. Penalties apply.
So what is disturbance and how can we avoid it?
- Keep domestic animals under control and well away from shorebirds. Every time shorebirds are forced to take flight, they burn vital energy.
- Avoid driving or operating all forms of vehicles, vessels and recreational devices near shorebirds. Imagine a shorebird confronting a kite surfer for the first time; it probably thinks it is the biggest predator it has ever seen!
- Don't drive along the beach at high tide or above the high-water mark — you'll destroy shorebird nests.
- If fishing from a sandbar, choose the opposite end to where the birds are gathered.
- Feral animals can kill shorebirds — you can report any sightings of feral animals to FeralScan or contact the Department of Agriculture and Fisheries on 13 25 23.
- Consider how your actions may disturb shorebirds. This can include where you set up camp or a simple stroll through a roost site at high tide.
- Prevent pollution — remember that almost all rubbish and pollutants discarded on the land end up in the bay.
How to watch shorebirds
For a good look at shorebirds, sit quietly at a distance, ideally in a bird-hide, and study them through binoculars or a spotting scope.
You can look out for birds that are tagged with coloured plastic leg "flags". Birds banded in:
- Moreton Bay have a green tag,
- north-western Australia have a yellow tag,
- southern Australia have an orange tag over a yellow tag.
Many other areas have unique colour flag combinations. For further details, please go to the Australasian Wader Studies Group and select "wader flagging program".
Noise, speed and movement easily disturb shorebirds. Avoid approaching flocks of birds where possible.
The Queensland Wader Study Group regularly conducts shorebird monitoring in Queensland and welcomes new members. For further information see Birds Queensland.
What if the shorebirds just disappear?
Unfortunately, around the world and within Australia, wetlands are rapidly disappearing and being developed for farming, housing, industrial and coastal developments.
As people place more demand on land, wildlife can just slip away unnoticed and be forgotten. Many areas that were once habitat for shorebirds are now unsuitable. This results in increased pressures on the remaining areas and a reduction of shorebird numbers in Moreton Bay.
If too much habitat is lost or disturbed local and international shorebirds and a vital link in the flyway will be gone.
Would we miss the cry of the curlew, the antics of a lifelong pair of oystercatchers or the spectacular overhead "V" formation of migratory shorebirds? What would happen to the delicate ecological balance of Moreton Bay if thousands of hungry shorebirds were lost? It would certainly be better not to have to answer these questions.
Resident Queensland shorebirds
|Common name||Scientific name|
|Beach stone-curlew||Esacus magnirostris (conservation status: Qld - vulnerable)|
|Australian painted snipe||Rostratula australis (conservation status: Qld - vulnerable)|
|Pied oystercatcher||Haematopus longirostris|
|Sooty oystercatcher||Haematopus fuliginosus (Conservation status: Qld - rare; national - least concern)|
|Common name||Scientific name|
|Black-tailed godwit||Limosa limosa|
|Bar-tailed godwit||Limosa lapponica|
|Little curlew||Numenius minutus|
|Eastern curlew||Numenius madagascariensis (Conservation status: Qld - endangered; national - critically endangered)|
|Marsh sandpiper||Tringa stagnatilis|
|Common greenshank||Tringa nebularia|
|Wood sandpiper||Tringa glareola|
|Terek sandpiper||Xenus cinereus|
|Common sandpiper||Actitis hypoleucos|
|Grey-tailed tattler||Tringa brevipes|
|Wandering tattler||Tringa incana|
|Ruddy turnstone||Arenaria interpres|
|Asian dowitcher||Limnodromus semipalmatus|
|Great knot||Calidris tenuirostris|
|Red knot||Calidris canutus|
|Red-necked stint||Calidris ruficollis|
|Pectoral sandpiper||Calidris melanotos|
|Sharp-tailed sandpiper||Calidris acuminata|
|Curlew sandpiper||Calidris ferruginea|
|Broad-billed sandpiper||Limicola falcinellus|
|Pacific golden plover||Pluvialis fulva|
|Grey plover||Pluvialis squatarola|
|Mongolian plover (now lesser sand plover)||Charadrius mongolus|
|Large sand plover (now greater sand plover)||Charadrius leschenaultii|
There are ten bilateral agreements for migratory bird conservation in the East Asian Australasian Flyway, involving seven countries. The three agreements involving Australia are JAMBA (Japan/Australia Migratory Bird Agreement), CAMBA (China/Australia Migratory Bird Agreement) and ROKAMBA (Republic of Korea/ Australia Migratory Bird Agreement).
In addition to bilateral agreements there are two multilateral agreements that are relevant to flyway conservation of waders. The Ramsar Convention (Convention on Wetlands of International Importance especially as Waterfowl Habitat) promotes wetland conservation, and the Bonn Convention (Convention on the Conservation of Migratory Species of Wild Animals) provides a multinational framework for the conservation of migratory species. In the East Asian-Australasian flyway, 15 of the 22 countries in the flyway have signed the Ramsar Convention.