Print

Print


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.
Need to cite this story in your essay, paper, or 
report? Use one of the following formats:

University of New South Wales (2008, April 13). 
Shorebird Numbers Crash In Australia. 
ScienceDaily. Retrieved April 17, 2008, from 
http://www.sciencedaily.com­ /releases/2008/04/080409170333.htm