Update from Mike on wild penguins in S America

>
> Dear PenguinPromises
>
> The penguins began arriving back in the colony in early October. The male
> penguins arrive about 10 days before the females, and gather on the beach
> waiting for the females to arrive. The pairs become separated during the
> winter migration, and this is how they meet up again. It is a reunion in
> which it is okay for the female to arrive late, but not the male.
>
> There are more male eggs laid than female eggs, so there are always more
> male penguins than females in the population. If the male looses his
> partner, it is more difficult for him to find another unattached female. It
> is therefore important for the male to be ready and waiting when his partner
> returns to the colony, in order to avoid loosing her to a competitor, of
> which there are many.
>
> By contrast, not only is it easier for the female to find a replacement
> partner, but she is also running against her own biological clock when she
> arrives at the colony. She is already carrying rudimentary eggs when she
> arrives home, and they need fertilizing shortly after arrival to ensure that
> they are laid at the proper time.
>
> If the female arrives back at the colony and the male has not arrived, the
> female will not wait long before pairing with one of the many unattached
> males. She does not really have much choice. If the eggs are not fertilized
> they will be reabsorbed, and the female will loose her chance to raise
> chicks for another year.
>
> To stop that from happening the males arrive about 10 days before the
> females, and the females renew the courtship with their usual partner. As a
> result of this protocol, Magellanic penguins are very faithful and usually
> remain with the same partner for life.
>
> Your penguin reunited again after the long separation during the migration,
> and the couple have spent the last few days making changes to the nest.
>
> The couple made a new nest under a different part of their bush. Last year's
> nest will have fleas that have been dormant in the bottom of the nest since
> last season. The fleas lie dormant in the soil over the winter and wake up
> again when they feel the warmth of the penguins back in the nest. Fleas and
> ticks that were on the penguin when they left on migration would have died
> after being so long in the water, so the penguins come back to the nest
> relatively free of parasites.
>
> Moving the nest a very short distance may possibly help cut down the number
> of fleas, but considering it is still around the same bush, it is unlikely
> to make much difference. Even if the penguins did prevent some of last
> year's fleas from getting back into their feathers, they soon pick up fleas
> again just walking through the colony. Sadly fleas are a burden that all of
> the penguins just have to put up with.
>
> We also have to put up with the fleas when working with the penguins.
> Although penguin fleas can only survive on penguins, they still bite people
> in an attempt to draw blood, and cause itchy spots like mosquito bites. They
> especially like getting into people's socks, and a visit to the penguin
> colony is often followed by itchy bites around the ankles. Thankfully
> penguin fleas cannot survive on human blood, so they soon die and cannot
> cause an infestation. A shower and a change of clothes at the end of the day
> is all that is needed to get rid of them.
>
> Magellanic penguins prefer to nest in burrows, but here the soil is too dry
> and sandy for making burrows. Anything more than a simple hollow would
> collapse. So the penguins here make their nests under the bushes, which give
> them some protection from bad weather and predators.
>
> Magellanic penguins always lay two eggs, with a separation of about 4 days
> between the first and second egg. We never disturb the penguins to take
> photos until they have laid their eggs. If we tried to take photos before
> the first egg is laid, the new penguins could possibly abandon their nest
> and make a new nest somewhere else. However once the eggs have been laid the
> penguins will not abandon the nest.
>
> The two eggs have now been laid, and I attach a new photo of your penguin
> incubating them.
>
> The eggs are large, weighing over 100 grams each, and take about 7 weeks to
> hatch. During that time both penguins take turns at incubating the eggs to
> keep them warm so that they can develop properly. One penguin stays in the
> nest lying over the eggs to keep them warm and hidden from predators, whilst
> the other partner goes to sea to catch fish. They swap over every two or
> three days so that both penguins can take turns at catching fish.
>
> The most common cause of egg loss is not predation, but rather penguins
> taking too long to return to the nest. Our studies show that penguins will
> abandon the nest if their partner does not return within about 6 days during
> the incubation. This is most common with inexperienced penguins nesting for
> the first time, and is usually caused by less experienced parents being
> unfamiliar with the surrounding area, and having trouble finding the shoals
> of fish.
>
> Inexperienced penguins also occasionally have problems locating their nest
> amongst the 150,000 other nests in the colony. People sometimes have trouble
> remembering where they parked their car, but imagine a parking lot with
> 150,000 lots, all hidden within a dense forest. The bushes are like trees to
> the penguins, who have no chance of seeing over the top to get their
> bearings (see second photo).
>
> The egg is a truly remarkable thing. Life on Earth began in water, and all
> embryos need to develop in water. So many groups of animals developed eggs
> in order to provide a self contained capsule that provides that aquatic
> environment on land where there is no water.
>
> Each egg contains exactly enough ingredients inside its shell to produce a
> baby penguin. That may sound obvious, but most animals have babies that vary
> in size. Penguins don't. The fertilized egg grows a network of blood vessels
> around the outside of the yolk, and then works inwards to turn the yolk into
> the baby penguin. The chick even hatches with some yolk left inside its
> stomach, to feed it during the first few days of life.
>
> The only thing the egg lacks is oxygen and warmth. The egg shell is
> sufficiently porous to allow oxygen to enter the egg, and for carbon dioxide
> to be expelled. The adult penguin provides the warmth through incubation.
> Cell growth requires the eggs to be kept within a certain temperature range,
> and if eggs are left exposed for too long, they cool down too much and fail
> to hatch.
>
> The main predators here are foxes, armadillos and skuas (large brown
> seagulls). However predators are rarely able to steal the eggs if the adult
> is guarding the eggs carefully. Magellanic penguins are very tough and have
> a fierce bite, which can cut the flesh down to the bone. Foxes and skuas
> would not dare risk a fight with an adult Magellanic penguin, so they keep
> well away from the nests if the penguin is on guard. They tend to circle
> around the colony looking for careless penguins that have left the eggs
> exposed for whatever reason.
>
> For the next 7 weeks there will be very little activity in the colony except
> for the changing over of the penguins as they take turns incubating the
> eggs. We visit each nest every few days to ensure that all is well, and to
> record any egg losses. In order to protect the penguins it is important to
> measure the percentage of eggs lost and to record the causes of egg losses.
> This important information is vital for protecting the penguins. Only by
> gathering this kind of information can we detect any new problems early on.
>
> Once the eggs hatch in December things will begin to happen more quickly.
> The chicks grow very rapidly, increasing their weight 30 times in just 10
> weeks, and I will keep you up to date with all the activity.
>
> Emails can sometimes go astray, so if it ever goes beyond two months without
> hearing from us, then let us know in case an update that we sent to you has
> failed to arrive. I can resend anything that has been lost.
>
> Adding our email address mbingham@penguins.cl to your Approved Senders List
> will help to ensure safe arrival of all our updates. This is especially
> important if you use Hotmail or Outlook, which have been very unreliable
> recently.
>
> I will write to you again in December when the eggs have finally hatched,
> with more information about your little adopted family.
>
> Kind regards, Mike
>
>
>
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