Shorebird Numbers Crash In Australia
ScienceDaily (Apr. 13, 2008) One of the world's
great wildlife spectacles is under way across
Australia: as many as two million migratory
shorebirds of 36 species are gathering around
Broome before an amazing 10,000-kilometre annual
flight to their northern hemisphere breeding grounds.
But an alarming new study has revealed that both
these migrants and Australia's one million
resident shorebirds have suffered a massive
collapse in numbers over the past 25 years.
A large scale aerial survey study covering the
eastern third of the continent by researchers at
the University of New South Wales has identified
that migratory shorebirds populations there
plunged by 73% between 1983 and 2006, while
Australia's 15 species of resident shorebirds -
such as avocets and stilts - have declined by
81%. The study is published in the scientific journal Biological Conservation.
It is the first long-term analysis of shorebird
populations and health at an almost a continental
scale and reveals a disturbing trend of serious long-term decline.
"This is a truly alarming result: in effect,
three-quarters of eastern Australia's millions of
resident and migratory shorebirds have
disappeared in just one generation," says an
author of the report, Professor Richard Kingsford.
"The wetlands and resting places that they rely
on for food and recuperation are shrinking
virtually all the way along their migration path,
from Australia through Indonesia, the
Philippines, Malaysia and up through Asia into China and Russia."
The study also revealed for the first time that
Australia's inland wetlands are particularly
important for migratory shorebirds, along with
the better-known coastal sites - such as Roebuck
Bay, Port Phillip Bay, the Hunter River estuary and Hervey Bay.
Of the 10 wetlands supporting the highest number
of shorebirds within survey bands across eastern
Australia, eight were inland and only two coastal.
This makes shorebirds vulnerable to the effects
of damming rivers and extraction of water. Four
of the ten wetlands had been substantially
reduced in size during the survey period.
"Loss of wetlands due to river regulation is one
of the more significant contributors to this
drastic decline, but it appears such a threat is
largely unrecognised in Australia's conservation
plans and international agreements," says
Professor Kingsford, who co-authored the report
with Silke Nebel and John Porter, of the UNSW
School of Biological, Earth and Environmental Sciences.
The fact that resident shorebirds in eastern
Australia have also suffered dramatic declines
points to serious conservation problems within
the continent, they say, and reflects the
pressures on river systems such as the
Murray-Darling Basin. Other shorebird populations
in Australia's north and west, however, may not have declined so much.
The migratory shorebirds make an annual flight
from Australia during March and April to their
breeding grounds in northern China, Mongolia,
Siberia and Alaska. These birds make the
extraordinary journey of to 10,000 kilometres
over a period of only a few weeks, some of them flying non-stop.
"Australia has international responsibilities for
the conservation of these species and it has
migratory bird agreements with Korea, Japan and
China in place, but these do not appear to be
stopping this long term decline," Professor Kingsford says.
As the migratory shorebirds wing their way up the
east coast of Asia (known as the East
Asian--Australasian Flyway), they are
increasingly vulnerable to many pressures.
Many are hunted but the most serious issue is the
loss of their staging habitat, places they stop
to recuperate during their arduous journey. Here
they need build up body reserves for the next
part of their journey. Sometimes, many migratory
shorebirds may use a single site.
The key staging site for the migratory shorebirds
leaving Australia is the Yellow Sea, where all 36
species concentrate, but the river catchments
draining into the Yellow Sea host a growing
population of about 600 million people in China
and South Korea (about 10% of the world's population).
"Agriculture and industry are progressively
reclaiming the tidal feeding grounds of migratory
shorebirds in the Yellow Sea" said Professor
Kingsford. "Our international agreements relating
to shorebird conservation (Ramsar Convention) the
Japan-Australia Migratory Bird Agreement (JAMBA),
the China-Australia Migratory Bird Agreement
(CAMBA) and the Convention on the Conservation of
Migratory Species of Wild Animals (Bonn Convention) do not seem to be working."
Saemangeum, the most important shorebird site in
the Yellow Sea, is being reclaimed with no
apparent effort on behalf of the South Korean or
Australian Government to stop it. "Australia could do better" says Kingsford.
"We need to properly recognise our international
obligations for shorebirds within our shores when
we decide to develop rivers and wetlands. We must
try to meet our side of the bargain for their
conservation if we are to influence other
countries to protect their breeding and staging grounds."
Identifying and adequately protecting wetlands of
high conservation value for migratory shorebirds
and protect their water supply is paramount, he believes.
Worldwide, shorebird numbers are in decline. Of
the 237 species with trend data, more than half
are in decline, while only 8% are increasing.
Shorebirds are spectacular migratory birds,
travelling almost the whole planet, from north to
south. They spend half their lives in Australia
and the other half breeding in Russia and China.
Adapted from materials provided by University of
New South Wales, via EurekAlert, a service of AAAS.
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Shorebird Numbers Crash In Australia.
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