The Sooty Albatross, Dark-mantled Sooty Albatross
or Dark-mantled Albatross, Phoebetria fusca, and the
Light-mantled
Albatross, Phoebetria palpebrata, are species of birds
in the albatross family. They breed on sub-Antarctic islands
and range
at sea across the Southern Ocean from South America to Australia.
Sooty Albatrosses are a type of Albatross that belong to Diomedeidae
family and come from the Procellariiformes order,
along with Shearwaters, Fulmars, Storm-petrels, and Diving-petrels.
They share certain identifying features. First, they have
nasal passages that attach to the upper bill called naricorns.
Although the nostrils on the Albatross are on the sides of the
bill.
The bills of Procellariiformes are also unique in that
they are split into between 7 and 9 horny plates. Finally, they
produce a
stomach oil made up of wax esters and triglycerides that is
stored in the proventriculus. This is used against predators
as well
as an energy rich food source for chicks and for the adults
during their long flights. They also have a salt gland that
is situated
above the nasal passage and helps desalinate their bodies, due
to the high amount of ocean water that they imbibe.
It excretes a high saline solution from their nose.
The Sooty Albatross is a medium sized albatross and measures
about 85 cm), with a 2 m wingspan. Adult body mass ranges
from 2.1 to 3.4 kg. It is sooty-brown with darker shading on
the sides of its head. It has a white crescent above and behind
its eye. Its bill is black with an orange or yellow sulcus.
The tail of this albatross is wide diamond shaped. Juveniles
are similar
to adults.
Their diet consists of squid, crustaceans, cephalopods, fish,
and carrion.
The Sooty Albatross is a colonial bird; however not to the degree
of other Albatrosses, as their colonies usually consist of 50
to 60 pair. They will build their nests on cliffs and steep
slopes. Whereas they can mate annually they only do so biennially.
This albatross nests on islands in the southern Atlantic Ocean
(Gough Island and the Tristan da Cunha group) and Indian Ocean
(Prince Edward Island, Marion Island, the Crozet Islands, Amsterdam
Island, and Kerguelen Islands). They forage in both
oceans north to about 30°S. |
Light-mantled Albatross, Phoebetria
palpebrata
http://www.savethealbatross.net/
This species is classified as Near Threatened
as it may be declining at a moderately rapid rate,
owing to bycatch on longline fisheries and perhaps the impacts of
introduced predators. T
hreats and population status both remain poorly known.
IUCN RED LIST
Phoebetria palpebrata has a circumpolar distribution in the
Southern Ocean.
It disperses over cold Antarctic waters in summer as far south as
the pack ice12 but ranges
north into temperate and sub-tropical seas in winter.
It breeds on South Georgia, Auckland, Campbell and Antipodes islands,
Amsterdam, St Paul,
Crozet and Kerguelen islands, Heard Is., Macquarie Is. and Prince
Edward and Marion islands.
The total annual breeding population is estimated at 19,000-24,000
pairs, equivalent to 58,000 mature individuals in this biennially
breeding species1,4. Population trends are poorly known.
On Possession Island (Crozet), there has been a decline of 13% in
15 years, though the population is
now increasing. The small population on Marion Island appears to
now be stable, following a decrease
between 1997-2002. Overall trends are uncertain as the majority
of colonies have not been studied,
but may be declining owing to bycatch on longline fisheries, plus
perhaps the impacts of
introduced predators at some sites.
2010. Phoebetria palpebrata. In:
IUCN 2010. IUCN Red List of Threatened Species. Version 2010.3.
<www.iucnredlist.org>. Downloaded on 08 September 2010.
http://www.savethealbatross.net/
The species breeds in loose colonies or small groups, and sometimes
is a solitary breeder.
The nest is built on a vegetated cliff ledge, or a steep slope,
sheltered from the prevailing westerly winds. Structurally it is
a low mound of peat and mud, 15–30 cm (5.9–12 in) high
and 45–55 cm (18–22 in) wide
at the base, with a cupped hollow at the top. It incorporates some
plant material and with a grass lining.
Around October or November,[ a single egg is laid, which is not
replaced if lost.
Both sexes incubate alternately in shifts that vary from a day or
two up to nearly a month in length.
The incubation period is 65–72 days.[4]. After hatching in
December or January, which takes 3 to 5 days,
the chicks are brooded in shifts for about 20 days, following which
they are left alone in the nests
while the adults forage, returning to feed the chicks by regurgitation
every 2–3 days.
Photo: Dimitri Damasceno
The entire nestling period from hatching to fledging, which occurs
in May or June, lasts 140-170 days. Pairs form committed pair-bonds
which may last for decades, being renewed through complex courtship
displays at the breeding site. On average, birds begin breeding
when they reach 8 to 15 years old,
after which they breed biennially, fledging a chick every five years
or so.
They are capable of breeding until at least 32 years old and living
to 40 or longer.
Range
map from
2010. Phoebetria palpebrata. In: IUCN 2010. IUCN Red List of Threatened
Species. Version 2010.3. <www.iucnredlist.org>.
Downloaded on 08 September 2010. (Island names supplied by www.vulkaner.no)
Light-mantled albatross - overview
BBC Natural
History Unit
http://www.arkive.org
The
part above about breeding: http://en.wikipedia.org/wiki/Light-mantled_Albatross
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