Penguins South America update

>
> Dear PenguinPromises
>
> The chicks have now left the colony and have gone to sea to begin life on their
> own. They are now swimming up the coast of Patagonia towards Brazil. In a few
> weeks time Promises will follow them to Brazil, but first there are things that
> all the adult penguins must do before they can leave.
>
> When young birds leave the nest they are said to have fledged. In reality the
> word refers to birds that can fly, but even though penguins cannot fly, the word
> fledged is still correctly applied to penguins in both common language and scientific
> reports.
>
> Once the chicks have fledged they are then called juveniles. The term juvenile
> refers to what might be considered a penguin version of a human teenager. They
> are now able to live independently from their parents and make their own way
> in the world, but they have still not finished developing to attain their full
> weight and strength.
>
> These juvenile penguins weigh just over 3 kg, which is almost half the weight
> of Promises. The difference in weight is due to the difference in muscle mass
> and bone density which develops over time. Summers are short this far south,
> so to avoid feeding chicks in winter, the chicks are 'fast tracked' to reach
> independence, and then they finish their physical development after leaving the
> colony.
>
> Although juveniles are almost the same height as Promises, their body is very
> different. When holding a juvenile penguin it has the feel of a soft toy. Its
> body is mostly fat reserves which are soft and squidgy. These body fat reserves
> are important to provide energy reserves that will keep the juvenile alive during
> the first few weeks as it learns to catch its own food.
>
> By comparison holding an adult penguin, like Promises, it is as firm to the touch
> as a car tyre, due to the strong bones and powerful muscles beneath the feathers.
> It is for this reason that juveniles take 5 years to reach breeding age.
>
> The juveniles have never been swimming before, so for the first few weeks their
> flippers get tired very quickly, and they need to take lots of short breaks when
> swimming. They swim for a few minutes at a time, and then float on the surface
> resting for a while, like the juvenile in the photo. Over the coming weeks and
> months their muscles will get stronger and they will spend less time resting
> and more time swimming.
>
> The juveniles' weak flipper muscles also affect their speed. The juveniles are
> not yet fast enough to catch fish, so for now they will have to eat slower moving
> creatures like shrimps and krill, which they catch amongst the beds of seaweed.
> That is the same brown seaweed that you see floating near to the coast all over
> the world. It is called kelp. Kelp beds are like underwater forests, full of
> delicious food if you are a juvenile penguin.
>
> The adult penguins eat almost 100% fish, but the juveniles have to be more flexible
> in their diet for the time being. For the next few weeks they will be grateful
> for anything that is slow enough to catch.
>
> Summer is now coming to an end, and it will start getting colder here on land
> before long. However the open ocean is so large that away from the shallows near
> to the beach the seawater does not get much colder in winter. The reason is because
> it is so vast and contains so much water.
>
> If you boil a kettle, after you turn it off the water inside stays warm for some
> time afterwards. That is because the heat has to escape for the water to cool
> down. The larger something is, the longer it takes for that heat to escape. A
> cup of hot water cools down quickly, but a large pot of water takes much longer.
>
> The South Atlantic Ocean stretches from South America to South Africa. It contains
> so much water that it would take years to cool down, and the winter isn't long
> enough for that. So for animals living in the ocean here, there is not much difference
> in temperature between winter and summer.
>
> The juveniles will not be getting cold in any case, because they are swimming
> towards Brazil, where it is nice and warm all year round, even on land. The juveniles
> will not begin laying eggs themselves until they are 5 years old, so they have
> no need to come ashore to make a nest until then. Penguins love living in the
> ocean, and they only live on land when they must. Penguins only come ashore to
> raise chicks and to moult their feathers.
>
> The juveniles will spend the next 5 years just eating and sleeping out at sea.
> During those 5 years they will build up their muscles and bones for the day when
> they will need to be fast enough to catch lots of fish to feed chicks of their
> own, just like Promises.
>
> So whilst the juveniles are away enjoying themselves, Promises and the other
> adults have some rest and relaxation of their own to take car of. The parents
> have been working from 5 o'clock in the morning until late in the evening to
> keep their chicks fed and healthy. That was such a sacrifice that the parents
> are now exhausted and have lost 20% to 25% of their body weight. It is important
> for Promises to now recover the weight lost during chick-rearing.
>
> So for the next few weeks Promises will go out to sea and remain there just eating
> and resting. Now that the chicks have left the nest there is no need for Promises
> to go back to the nest at night. To make a five to six hour round trip each day
> between the fish and the nest makes no sense now that there are no chicks to
> feed. So the penguins remain where the fish are, and sleep bobbing up and down
> on the waves out at sea.
>
> Building the weight back up is very important for Promises, because in a few
> weeks time the penguins have to change all their feathers, which is called moulting
> or molting, depending on where you live. For penguins, moulting is a big deal
> because they cannot go swimming during the moult. Since the fish live out at
> sea, that means that Promises must go for almost a month without being able to
> eat anything. So you can see why eating plenty of food now is important.
>
> I will write to you again in a few weeks time when Promises has finished the
> mini-vacation out at sea, and is back in the nest again ready to begin the moult.
>
> Kind regards, Mike
>
>