SpecieS and climate change: - IUCN

EmpEror pEnguinS AnD CLimATE CHAngE
of global warming reported by the Intergovernmental
Panel on Climate Change (IPCC). The east coast of the
Peninsula has also warmed, though less rapidly, and
here the largest warming has taken place in summer and
autumn.
Significant warming has also been observed in the
Southern Ocean, with upper ocean temperatures to
the west of the Antarctic Peninsula having increased
by over 1°C since 1955. As a result, sea ice cover may
decline by around 25% (although there are considerable
uncertainties associated with this prediction). Changes
in seasonal sea ice have already been observed,
including sea ice declines in the Antarctic Peninsula
region.
Thinning sea ice:
Changes in seasonal sea ice are potentially a
considerable threat to breeding Emperor Penguins.
While it is sometimes argued that a reduction in seaice
extent could actually benefit Emperor Penguins
by reducing the distance adults have to travel to feed
during the breeding season, there are also numerous
and important negative effects that should be taken into
consideration.
The iuCn red List of Threatened Species
Pack ice extent reaches its minimum in late summer.
A this time, however, ice is still essential as a platform
for crèched chicks before they fledge, and later, for
adults so that they can successfully moult. The platform
is needed for growing chicks and for moulting adults
as they are unable to survive without their waterproof
feathers. Early ice break-up in warm years has caused
chicks to be swept into the ocean and drowned.
Should global temperatures increase by 2°C, scientists
estimate that colonies to the north of 70°S would
probably become unviable. This means that 40 percent
of all colonies, and almost 40 percent of the total
breeding population of Emperor Penguins would be
affected.
In 2001, a large iceberg collided with the Ross Sea
ice shelf in the vicinity of a well-established Emperor
Penguin breeding colony. The sea ice supporting a
considerable proportion of the colony was broken.
In addition to the direct impacts of the collision, the
colony was affected for several years afterwards by the
continued presence of the iceberg. Chick production
was markedly reduced and remained lower than usual
for some years. With increases in temperature and
thinning of the sea ice, such incidences are likely to
occur more frequently.