What is a Shorebird? |
|
Shorebirds, also known as waders, gather to feed in intertidal areas or on the fringes of freshwater wetlands. They generally have long legs in relation to their body size, and their bills are specially adapted to their diet and habitat. For example, the long, probing bill of the endangered 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 and are the most threatened single group of bird species. Fifteen species of shorebird are resident in Australia and an additional 37 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, millions of shorebirds migrate to and from Australia along the East Asian-Australasian Flyway.
Shorebirds have the most amazing physiological adaptations to enable them to make their migratory journeys, but unlike seabirds (e.g. shearwaters, gulls, albatross etc.) they do not have webbed feet, so are not adapted to paddle on the water. This means that although their southern overwintering habitat is the shoreline, or intertidal zone, their movements are entirely governed by the tide as they cannot continue to feed once the tide is in.
In order to reserve enough energy to migrate these small birds need to eat and eat until they are about double their normal size - so they set off at their top weight which seems like an aeronautical anomaly. Despite this, shorebirds are the marathon-winners of flight, having been recorded flying in a single stretch as far as from Siberia to New Zealand - a flight lasting about 8 days and nights. What is more, this group of birds do not soar - so they are physically flapping all the way, at an average of some 60 km per hour. Many physiological changes occur to allow them to do this, including the temporary atrophying of organs to make their bodies lighter, the ability to metabolise body fat into water to keep them hydrated, and the ability to sleep with half their brain (micosleeps)!
For more information I recommend the following websites:
Birdlife Australia: www.birdlife.org.au/projects/shorebirds-2020
Australian Wader Studies Group: www.awsg.org.au
Global Flyway Network: www.globalflywaynetwork.com.au
Australian Government: www.environment.gov.au/biodiversity/migratory-species/migratory-birds
Shorebirds make up about 10 per cent of Australia's species of birds and are the most threatened single group of bird species. Fifteen species of shorebird are resident in Australia and an additional 37 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, millions of shorebirds migrate to and from Australia along the East Asian-Australasian Flyway.
Shorebirds have the most amazing physiological adaptations to enable them to make their migratory journeys, but unlike seabirds (e.g. shearwaters, gulls, albatross etc.) they do not have webbed feet, so are not adapted to paddle on the water. This means that although their southern overwintering habitat is the shoreline, or intertidal zone, their movements are entirely governed by the tide as they cannot continue to feed once the tide is in.
In order to reserve enough energy to migrate these small birds need to eat and eat until they are about double their normal size - so they set off at their top weight which seems like an aeronautical anomaly. Despite this, shorebirds are the marathon-winners of flight, having been recorded flying in a single stretch as far as from Siberia to New Zealand - a flight lasting about 8 days and nights. What is more, this group of birds do not soar - so they are physically flapping all the way, at an average of some 60 km per hour. Many physiological changes occur to allow them to do this, including the temporary atrophying of organs to make their bodies lighter, the ability to metabolise body fat into water to keep them hydrated, and the ability to sleep with half their brain (micosleeps)!
For more information I recommend the following websites:
Birdlife Australia: www.birdlife.org.au/projects/shorebirds-2020
Australian Wader Studies Group: www.awsg.org.au
Global Flyway Network: www.globalflywaynetwork.com.au
Australian Government: www.environment.gov.au/biodiversity/migratory-species/migratory-birds