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El Niño
The El Niño phenomenon is a large-scale
climate event that is manifest around the world. And
for millions of people it is a cause for concern because
it causes excessive rainfall or severe drought, taking
a toll on their standard of living.
The alteration of the climate
occurs as a result of a rise in surface water temperatures
across a large area of the Pacific Ocean, an anomaly
that affects atmospheric conditions. The variation
is described as an oscillation, as after the temperature
rises, it can often fall below normal, creating the
climate phenomenon known as La
Niña.
El
Niño is cyclical, occurring every four to seven
years, and its intensity varies. Some of the most
severe
episodes of the phenomenon have caused temporary
climate shifts resulting in starvation - from drought
- or at the other end of the weather spectrum, heavy
rains with massive flooding.
In Peru, where the warm ocean
current arrives from off Australia, is where the name
El Niño is thought to have originated, as fisherfolk
usually detected the changes in sea temperatures around
Christmas, and dubbed it Baby Jesus. Peru is one of
the countries that feels the greatest impact from
the phenomenon and has institutions that continuously
monitor the Pacific's temperatures.
But other countries also keep
watch. The U.S. National
Oceanic and Atmospheric Administration (NOAA)
constantly tracks ocean temperatures, using satellites.
Planning is important, given
that El Niño is a natural occurrence and cannot be
prevented. There are mentions of climate shifts in
the distant past that are believed to have been linked
to El Niño. And there are historic
accounts about the phenomenon dated as long ago
as the late 16th century.
NOAA:
El Niño
What
Is El Niño?
Top
10 El Niño Events of 20th Century
Children
of the Tropics: El Niño and La Niña
El
Niño for Kids
Yahoo!
Directory of El Niño websites
The Elephants
African and Asian elephants are
the largest land animals on the planet, the sole survivors
of a family known as Proboscidea. Their lives in modern
times are marked by a conflictive coexistence with
human beings.
In the past,
the Proboscidea order was made up of more than 300
different species, but all became extinct, except
the two species we know today. The African elephant's
scientific name is Loxodonta africana, while the Asian
elephant is known as Elephas maximus.
Characteristics such as their
great size and their trunks have always caught the
attention of humans. But elephants have other unique
qualities: the live in close-knit families, express
affection in unusual ways and - as the saying goes
- elephants never forget.
They also have ivory
tusks, an attribute used in self defense that paradoxically
has been the main cause of their shrinking population.
Poachers kill
these giant beasts for their tusks because of the
high price ivory fetches on international markets.
There are numerous worldwide initiatives aimed at
saving the elephants, including sharp restrictions
on the ivory trade.
Meanwhile, there are other sources
of conflict between elephants and humans who share
the same ecosystems.
In some cases, people complain
that there are too many elephants in a given area
as a result of conservation
efforts, and they have even asked for a softening
of restrictions on the ivory trade. In others, the
elephant families are finding it difficult to survive
in areas where the original ecosystem has been altered
by farming.
Portal:
Elephant Information Repository
WWF:
Threatened Species: Elephants
Save
the Elephants
Living
with Elephants
Elephant
Sanctuary
Elephant
Care International
Treaty
against Ivory Trade
Smart Cetaceans
Dolphins have been popular with
humans since ancient times due to their astonishing
ability to learn and their extraordinary behaviors.
But while they are admired by young and old alike,
they suffer the impacts of human activities and are
not strangers to the threat of extinction.
There are 70 species
listed in the suborder of cetaceans known as 'Odontoceti'
in the classification of animals. More informally,
these are "whales with teeth", and cover
all sea- and river-dwelling dolphins.
According to information
found on the Internet, there are some 30 ocean dolphin
species and five river dolphin species.
Dolphins are mammals, meaning
mothers nurse their young, and are the result of a
long process of evolution, which experts say began
with creatures that lived on land. An important trait
of this group of species is that, unlike fish, and
like their cousins the whales, dolphins must breath
air.
These excellent swimmers can
reach speeds of 40 km per hour. They also possess
a sophisticated sonar system that allows them to locate
objects in the water around them.
But one of their most astonishing
characteristics is the relatively large size of their
brains, which determines intelligence. Dolphins are
naturally curious and can easily learn behavior taught
by humans.
The survival of dolphins, however,
is at risk. Many fall victims to fishing nets, a problem
that is the focus of several conservation
campaigns worldwide. There is also a great deal of
criticism about keeping these extremely intelligent
animals in captivity
and using them in marine shows or in experiments.
Species
of Dolphins
International
Dolphin Conservation Program
Thinkquest:
Dolphins (educational)
Discovery
Channel: Dolphins
FAQs
about Dolphins
Similarities
between Humans and Dolphins
Greenpeace
Foundation: Dolphin-safe campaign
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