This is SCIENCE IN THE NEWS in VOA Special
English. I'm Bob Doughty.
I'm Faith Lapidus. This week, we will
tell about newly-found organisms that are said to be among the oldest living
organisms on Earth. And, we will tell
about the first complete report of bird populations in the United States.
research team says it has found corals that are more than four thousand years
old. The corals were discovered at the
bottom of the Pacific Ocean, near the Hawaiian Islands. The team made the discovery with a vehicle
designed to operate deep underwater. At
depths of nearly four hundred meters, the researchers found the oldest examples
of two species of coral. One is a kind
of deep-water black coral called Leiopathes. The other was a gold coral, called
report on the team's discovery was published recently in the Proceedings of the
National Academy of Sciences.
The team collected pieces of the coral and then used
radio-carbon dating methods to find their age.
The tests showed the organisms were, in fact, much older than reported
in earlier estimates.
One of the researchers was Brendan Roark of Texas
A-and-M University. He says the
Leiopathes corals were shown to be about four thousand two hundred sixty-five
years old. The Gerardia is believed to
be about two thousand seven hundred forty-two years old.
The age of
the corals would make them among the oldest living creatures in existence. Scientists know that some of the Bristlecone
pines in northern California are also more than four thousand years old.
corals face numerous threats. They
include illegal harvesting and activities linked to deep-sea fishing. Other threats include human pollution,
acidification from carbon dioxide and rising temperatures in Earth's
Roark says corals are important because they support many other forms of sea
life. He says they also can show part of
the ocean's ancient history. Corals have
hard, stony skeletons that grow like tree trunks. The skeletons have growth rings that
represent ocean water conditions at the time.
Professor Roark says knowing the age of the corals
might help scientists understand earlier water conditions and ocean surface
productivity. And, he says the discovery
will add to what scientists know about Earth's changing climate.
share our environment with many organisms.
But few give us more pleasure than birds. Their beauty and songs have become part of
our understanding of what a healthy environment should support.
a report released in March shows that many kinds of American birds are in
trouble. The report is called "The State
of the Birds United States Two Thousand Nine."
It says that nearly one third of about eight hundred bird species in the
United States are threatened in some way.
The report is said to provide the first complete study
of American bird populations. It was
based on three separate studies by a partnership of government agencies and
environmental groups. The groups include
the Cornell Lab of Ornithology, the National Audubon Society and the American
of the information came from observations made by thousands of volunteers in
more than four thousand places over forty years. The United States Fish and Wildlife Service
led the effort to combine the information into one report.
Secretary Ken Salazar praised the report as an important scientific document on
the health of American birds. But it is
not only a warning about falling bird populations. The health of bird species tells researchers
a lot about the condition of the environment.
study grouped birds by the environments in which they live. It said grassland bird populations fell by about
forty percent in forty years. That was the
biggest drop reported. One reason for
this is the disappearance of grasslands in the central United States. The report says only two percent of the
grasslands that existed two centuries ago remain today.
depend on their environment to provide food and shelter. The report said loss of habitat is the
biggest threat to American birds.
Sixty-seven species are federally listed as endangered or
threatened. But the report lists one
hundred eight-four species that are considered in danger because of limited
habitat, serious threats or falling populations.
The report also notes successes in bird conservation
efforts. For example, the numbers of
many wetland birds have recovered since measures were taken to protect more
than twelve million hectares of wetlands.
hundred thirty-nine wetland species have increased in number since the late nineteen-seventies. Pelicans, herons and geese are just a few of
many recovering wetland species.
Numbers of America's national bird, the bald eagle,
have recovered largely because of measures to fight pollution. In nineteen seventy-two, the federal government
banned most uses of the insecticide D.D.T. The chemical used to kill mosquitoes also
caused bird egg shells to thin and break.
Species like the bald eagle, peregrine falcon and osprey nearly
disappeared. Now, their populations seem
But threats to other species continue to grow. Land development and agriculture are just two
uses of natural resources that change and destroy environments that birds need. The cutting of forests is threatening woodland
species like the Northern Spotted Owl.
In addition to loss of habitat, birds face many other
man-made threats. The report says up to
one billion birds die each year from flying into objects like power lines,
windows and tall buildings.
Environmentalists are studying ways to reduce this
number, but these efforts are only beginning.
Climate change is one of
the least understood threats to birds.
The report says temperatures are estimated to increase by several degrees
Celsius in the next one hundred years.
And sea levels could rise by one half meter.
Already, rising temperatures have had an effect on
migratory birds. Studies show that some
American Robins are appearing in their nesting areas two weeks earlier than
thirty years ago. Other birds, like the
red-winged blackbirds and eastern bluebirds, are laying eggs earlier because of
warmer temperatures. The fear is that,
as birds move to nesting areas earlier, they will arrive before food is
Birds native to one state are of special concern to
wildlife experts. More than one third of
all threatened or endangered bird species in America live on the Hawaiian
Islands. Each island is home to a rich
collection of animal and plant life. One
hundred thirteen bird species are found nowhere else.
bird species have disappeared forever since people first arrived on the
Hawaiian Islands one thousand seven hundred years ago. Today, thirty-one Hawaiian species are
federally listed as endangered or threatened.
Non-native plants, animals and diseases are the main
threats. Non-native animals like rats,
cats and mongooses kill flightless birds and raid nests. Also, the loss of habitat to development and
agriculture continue to endanger many rare species.
King works for the Fish and Wildlife Service.
She says the main message of the report is that conservation measures
work when they are put in place. The
successful recovery of some well-known species is evidence of this. But more needs to be done. She says there currently are not enough
programs to study bird numbers and behavior.
between public, private and tribal groups can help to provide the resources
needed to protect America's birds. But
Miz King says the American people are an important part of the solution, too.
Americans spend one hundred twenty-two billion dollars
on watching wildlife each year. And,
millions of Americans enjoy watching birds.
But the economic value of wild birds is only part of their
importance. They also represent a part
of a healthy environment that cannot be replaced.
SCIENCE IN THE NEWS was written by Mario Ritter and Brianna Blake, who was also
our producer. I'm Faith Lapidus.
And I'm Bob Doughty.
Read and listen to our programs at voaspecialenglish.com. Join us again next week for more news about
science in Special English on the Voice of America.