South America Update – June 2018

Dear PenguinPromises

The annual moult is now over, and Promises can now enjoy a few months of rest
out at sea before returning home to breed again in October. By now Promises will
be swimming along the coast of northern Argentina, and will be continuing northwards
along the coast of Uruguay and Brazil in the days and weeks to come.

This is their winter migration, and the penguins do not have any particular destination
in mind.  They simply head northwards towards the warmer weather and brighter
sunshine, in order to escape from the gloomy winter weather during the Austral
winter.

Magellanic penguins catch their food at about 25 to 30 metres below the water
surface. That is the equivalent of a ten storey building underwater. It requires
good daylight for Promises to be able to see and catch fish at such a depth,
but during the winter the days become short and gloomy around the penguin colonies.

People living in Scotland or Alaska know how long the days are in summer, and
how short and gloomy they are in winter. Our colonies are on a similar latitude,
but in the southern half of the world, and so we have the same problem with short
days during the winter.

Being so far south is great for the penguins during the summer, because they
have long hours of good quality sunshine to catch food for the ever hungry chicks.
That is one of the reasons that they breed this far south. However in winter
the days become so short and gloomy that it gets difficult to see the fish to
catch them. So the answer is for Promises to head north, away from the pole and
towards the equator, where there is better daylight during the winter.

Of course the penguins never travel as far north as the equator. Brazil is far
enough to find good sunshine in winter, so that is where the penguins go. It
is not like the migration of birds which fly long distances in a few days. There
is no rush for Promises. The penguins travel nice and slowly, swimming a short
distance each day, taking lots of time to rest and to catch fish. It is all about
enjoying the journey and not worry about the destination.

In actual fact, the penguins stay several kilometres away from the coast all
the time, so as far as sight-seeing goes there is not much difference in the
view wherever they go. Uruguay and Brazil both look exactly the same from the
penguins’ point of view. If you can imagine a penguin’s eye level being about
2 inches above the water, you will realise that in the open ocean Promises can
only see as far as the next wave.

The penguins never leave the water at all during their whole migration. The sea
is their real home, and there are only three reasons for Promises to come out
of the water.

Firstly penguins have to come out of the water to lay eggs. If penguins laid
their eggs in the water they would just float away. The eggs also have to be
kept warm. Birds are warm-blooded animals, so unlike fish their eggs and chicks
have to be kept warm to survive. The cold seawater would kill the eggs, so the
eggs have to be kept in a nest on land, forcing Promises to come ashore in October
to incubate the eggs.

Then after the eggs hatch, Promises must continue coming ashore to raise the
chicks. The chicks cannot swim when they hatch, and just like the eggs they would
die if they got cold, so they have to stay on land in the nest until they are
big enough. Until then Promises must continue coming ashore to feed them in the
nest.

I attach a photo showing what a game it is for the parents to feed the chicks.
As you can see from the photo the chicks often put their beak right down into
the parent’s throat to get the food. They do that to stop the food being stolen
by their sibling (brother or sister). You can see in the photo how the sibling
is waiting for any chance to snatch a bit of food should the opportunity present
itself. Feeding the chicks out in the water would be very difficult.

Finally, as you know, Promises must come ashore to moult as I recently mentioned.
Those are the only three reasons that penguins come ashore of their own free
will. When penguins do not have eggs or chicks, and are not moulting, then they
are out at sea. The only exception is if they become oiled or injured, in which
case they would usually come ashore, but that is thankfully a rare occurrence.

It is not surprising that penguins prefer to live in the water. Penguins look
awkward and clumsy on land, but they are masters of the sea. You might not think
so but Promises can swim faster than you can run, unless you are an Olympic athlete.
Large penguins like King penguins can also dive up to a mile below the surface,
which is deeper than a submarine.

There is no bird on Earth that can swim as fast as a penguin. You probably think
that ducks are good swimmers, but in fact ducks just float on the surface and
occasional dive under the water. They are also very slow. Penguins can swim much
faster than a duck. Actually, thinking about it, Promises can run faster than
a duck too. Ducks are lucky that penguins don’t eat bread !

Cormorants, Razorbills and Puffins are slightly better swimmers, but none of
them come close to Promises for speed and endurance. No other bird has the ability
to swim quickly and for long distances like penguins. So even though penguins
look comical, they are in fact perfectly adapted to their lifestyle.

I will write to you again in a few weeks time, by which time Promises will be
off the coast of Brazil, and I will present you with the results of last season’s
fieldwork.

Best wishes,  Mike

South America – June 2018

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