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 [email protected] 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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