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Monday 12 December 2011

A flight of Albatrosses

Albatrosses (of the Diomedeidae family) are part of the same order of birds that have Shearwaters, Fulmars, Storm-petrels, and Diving-petrels as members.


To be played whilst reading this particular blog ...http://www.youtube.com/watch?v=8scHKFwr0og

All Albatrosses have nasal passages that attach to the upper bill called 'naricorns', (though the nostrils of the Albatross are on the sides of the bill). The bills are also odd - split into between 7 and 9 horny plates. The other oddity is that the bird produces a stomach oil - made up of wax esters and triglycerides - that is stored in the proventriculus, (a standard bit of avian anatomy - a sort of glandular part of the stomach that may store and commence digestion of food before it progresses to the gizzard). This oil, so produced, 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.

I first saw an albatross whilst at sea with Margaret, just off the coast of Ulva Island - a tiny islet off Stewart Island, New Zealand. We spread some cut up dead fish as bait and the birds that arrived to feed were Black-Browed Albatrosses (Thalassarche melanophrysor), 'Mollymawks' in the local jargon. It is the Albatross most likely to be found in the Northern Hemisphere (but this is incredibly rare anyway - on several occasions a Black-browed Albatross has summered in Scottish Gannet colonies - Bass Rock, Hermaness and now Sula Sgeir - for a number of years. Bird experts think the sighting was of 'Albert' - the same bird each time).

It is one of 19 declining species of Albatross - from a total of 21 species in total. It's size is l .. a ... r ... g ...e - see the picture of one seeing off a seagull! The wing span could be nearly 2.25 metres! ... big birds! Their beaks looked like plastic ... and stuck on. Presumably efficient ... its food includes fish, squid, crustaceans, carrion, and fishery discards. It is the most vulnerable to long line fishing. It is also known to steal other sea bird's food!

The second species we were lucky enough to see was the 'Waved Albatross', (Phoebastria irrorata), also known as the 'Galapagos Albatross' and the only member of the family located in the tropics. The name 'Waved Albatross' comes from the wave-like pattern of its feathers on the adult birds. When they forage, the Waved Albatross follow straight paths to a single site off the coast of Peru, about 1,000 km to the east.

The Waved Albatross is, like the Black-browed, only a "medium-sized" albatross, measuring about 90 centimetres long, weighing about 3.5 kg and having a wingspan over 2 metres. The distinctive features include yellowish-cream neck and head, mostly brownish bodies. and very long, bright yellow, bill. They have chestnut brown upper parts, brown upper-wings, back, and tail, along with a whitish breast and underwings and have blue feet. Their lifespan can be 40 to 45 years.

They breed primarily on Española (Hood) Isla in the Galápagos archipelago (the oldest and the southernmost). During

non-breeding season they will shift to the east and southeast to the continental shelf region off the coast of Peru and Ecuador. The steep high cliffs are perfect runways for these large birds, which take off for their ocean feeding grounds near the mainland of Ecuador and Peru abandoning the island between January and March. Landing is more of a crash!

Known to be endemic on the island, Española Isla is the waved albatross's only nesting place, so has the vast majority of the world's population of the bird too. Each April male Albatross return to Española, followed shortly thereafter by their mates. The courtship of the Waved Albatross is a very elusive and spectacular sight to see. It includes:

- rapid bill circling
- bowing
- gaping or yawning
- beak clacking or fencing
- an upraised bill to make a 'whoo hoo' sound (the Sky Moo!).

Mating for life, their ritual begins with the male's annual dance, (to re-attract his mate). The performance can take up to 5 days. We watched one, enthralled, as this happened right in front of us - inches away! It lasted oh, almost ten to fifteen minutes and ended with the female deciding this wasn't her mate, and promptly left! (It's happened to me!).

Copy and paste in a browser this footage. http://video.google.com/videoplay?docid=4884152789466423754

Once the pair is successfully reacquainted they produce a single egg and share the responsibility of incubation. The colony remains based on Española until December when the chick is fully grown. By January most of the colony leaves the island to fish along the Humboldt Current. Young albatross do not return to Española until their 4th or 5th year when they return to seek a mate.

Perhaps the most beautiful birds in the world ... they glide like angels.