May 2017 – Penguin Winter Migration
The penguins have now left the colony on their winter migration. The last few
months have been hard for Promises, laying eggs, feeding hungry chicks, and finally
changing feathers. Now the penguins have a few weeks to rest and relax. I attach
a photo showing just how many penguins gather together for the winter migration.
This photo was taken from a boat, so my apologies that it is not as sharp as
most of our photos.
Penguins are social animals and they like to keep together in groups. They make
nests and raise the chicks together in large colonies, and they also migrate
together in large groups. However partners do not remain together during the
It is not that the partners deliberately go their own way during the migration,
it is simply not possible to keep track of individual penguins out at sea. The
open ocean is hardly ever flat calm. There are virtually always constant waves.
Floating on the water surface with the head barely above the water, Promises
can only see as far as the nearest wave in any direction, which is rarely more
than 5 or 10 metres. Underwater the visibility is not much better either.
Even if a pair tried to remain together, the first time one of them went chasing
after a fish they would loose contact with their partner. Finding them again
amongst hundreds of other penguins swimming around that all look virtually the
same would be impossible. That is why pairs do not remain together during the
migration, but they do meet up again back at the nest in October. The nest is
their home, and that is where they return to meet up again with their partner
when it is time to lay eggs.
Here in southern South America we are not too far from the South Pole, so the
further south we go the colder it gets. Northwards is the only direction for
Promises to travel in search of better weather and longer hours of sunshine.
Since Promises cannot fly like other birds, that restricts the winter migration
to places that can be reached by swimming within a reasonable time frame. Here
in the southern Atlantic Ocean, the only sunny destination that Promises can
reach is Brazil, so that is where all our penguins go during winter.
Even so, it is a very long way to swim to Brazil, about 4,000 kilometres. It
will take Promises several weeks to arrive. However the penguins are in no rush,
and the migration is a bit like an ocean cruise for Promises. Each day the penguins
spend a few hours leisurely swimming north, taking time to relax and eat lots
of fish. They spend lots of time sleeping too, just bobbing along on the waves.
Their migration is a role model for life in general. It is all about enjoying
the journey, and not worrying too much about the exact destination, which is
The penguins don’t actually have a fixed destination in mind. Each day instinct
guides them north, but only as far as they feel like swimming each day, and gradually
the weather gets a little bit warmer and the days get a little bit longer. The
sunny weather and longer hours of daylight make it easier for the penguins to
catch food. Penguins need to see the fish in order to catch them, and it requires
good sunlight to see the fish clearly several metres below the water.
Sometimes the penguins hardly reach Brazil at all before it is time for them
to turn around and head back home to begin egg-laying. During other years they
travel way beyond Rio de Janeiro. Every year is different.
The food is also different during the migration. Back home the penguins mostly
eat the same type of fish every day (Sprattus fuegensis), but during the winter
migration they get to eat other kinds of fish. Penguins can eat almost any kind
of fish, but the fish have to be small enough to swallow whole. Penguins don’t
have teeth, so they cannot chew their food, which is why they have to swallow
the fish in one piece. That limits the size of fish which Promises can eat.
It sounds very tiring having to swim such a long distance, but for Promises it
is very leisurely. Penguins have neutral buoyancy, so they just float on the
water like little boats when they are resting. They only need to flap their flippers
to move forward. Watching them playing in the water makes me think of somebody
lying face-down on a sunbed with their arms dangling in the water to paddle –
all very relaxing. The penguins only need to exert themselves to catch the occasional
There is no doubt that penguins are always happiest in the water. Swimming is
far easier for penguins than walking, and during the winter migration they never
leave the water at all. They could if they wanted to. There are lots of remote
beaches and islands along the way where the penguins could come ashore if they
wanted to, but they simply choose not to. Penguins only come out of the water
when they are forced to do so, for example to lay eggs, raise the chicks, and
to change their feathers.
I will write to you again in a few weeks, by which time Promises will be floating
around in the water a few kilometres offshore from some Brazilian beach.
Best wishes, Mike
Dear Penguin Promises
The chicks have been growing quickly and they are now almost as big as Promises.
They now leave the nest each day to explore the area around the nest in preparation for leaving the colony. I attach a photo of the chicks so that you can see just how big they have grown in such a short time..
Childhood is very short for a penguin. The chicks leave the nest to begin life on their own after just two months from hatching. During those two short months they increase their weight 30 times, from about 100 grams at birth to about 3000 grams when they leave. They change from tiny balls of fluff into full-sized penguins in just 8 weeks, when food is in good supply, which it is here.
At the moment whenever the weather is nice, the chicks leave the nest to do their flipper exercises. They flap their flippers up and down as fast as they can as though they expect to fly, but these exercises play a very important role in building good strong flipper muscles which the chicks will need when they leave the colony to begin life as a juvenile. Once out at sea they will have to swim long distances and need to be ready for the journey.
The chicks have fluffy chick feathers when they are small. These fluffy feathers are wonderful for keeping the chicks nice and warm when the feathers are dry, but the fluffy feathers are no use at all when they get wet. They soak up water like a sponge and make swimming impossible. So the chicks are now shedding their fluffy chick feathers and replacing them with sleek, shiny feathers that are waterproof.
The new juvenile feathers do not soak up the water. They are coated with wax which the penguins produce in a gland near to the tail. They spread this wax over the feathers during grooming. Penguins spend a lot of time grooming themselves and each other. Keeping the feathers waxed is one of the reasons for grooming, and the other reason is to remove ticks and fleas.
The new feathers will keep the chicks warm and dry even when swimming. The waxy feathers interlock together using microscopic hooks, providing a waterproof barrier that works in a similar way to the black wet-suits which people use for diving and surfing. The new feathers are like the feathers of Promises, but without the black lines of the adults which only appear when the penguins reach 5 years of age..
Once these new feathers have finished growing the chicks will be ready to leave the colony and go out to sea on their own. Penguins are born to swim and are always happiest out in the open ocean. The excitement when the chicks first enter the water is a joy to see. They splash around, leap in and out of the water, and float around on their backs splashing water over themselves to bathe.
At the moment it is a difficult job for Promises to catch enough food to feed the ever hungry chicks. Their rapid growth means that the chicks can eat more than Promises can catch. The adults both set off as soon as the sun rises at about 5 o’clock in the morning, and spend all day out at sea catching fish for the chicks. The chicks cannot go into the water yet, until the new feathers are ready, so they must stay at home and wait for supper.
The chicks don’t get breakfast or lunch, just supper.
The adults don’t get home until late afternoon or early evening, and even after supper the chicks still complain that they are hungry. The chicks in our colony are well fed and food supply is not a problem here, which is why the chicks here grow so quickly. In colonies where food is in short supply, such as in the Falkland Islands, chick growth can take as long as 16 weeks, twice what it is here.
The chicks here eat a quarter of their own body weight every single day. The adults work 12 to 15 hours a day catching enough food for the chicks. They get no weekends and no days off to relax. Before they started rearing the chicks the adults weighed about 6 kg and now they weigh less than 5 kg. They have lost more almost 20% of their body weight because of working so hard to feed the chicks.
It is just as well that they only have to do it for two months, otherwise poor Promises would disappear altogether.
Despite their frenetic flipper exercises, the chicks lack the strength and stamina to be fast enough to catch large fish when they leave, so during the first few months at sea they fish amongst the kelp beds feeding on small fish, shrimps and other crustaceans.
Gradually as they spend more time at sea, and build up the flipper muscles, they will become faster and will be able to leave the kelp beds and catch slightly larger fish, but it takes four years for the youngsters to fully develop the strength and stamina that they need to begin raising families of their own. Experienced adults loose 20% of their body weight rearing the chicks, which is why younger juveniles would not have the strength and endurance to raise chicks successfully.
Many people ask if they can adopt the chicks, but unfortunately we are unable to offer the chicks for adoption. I wish we could. The problem is that when the chicks leave the colony, most will not return to the colony until they are 5 years old and ready to raise chicks of their own. That means that people adopting chicks would not get any news or photos of their penguin for 5 years.
Once the chicks have left, Promises will take a long rest out at sea just catching fish and relaxing, so that they can recover the weight that they have lost over the last few weeks. This feeding and recovery is very important because about a month after the chicks have left the adults must return to the colony in order to change all their feathers, which means a period of about three weeks stranded ashore with no food. It is important for Promises and the adults to recover their lost weight before beginning a long period without food.
I will write to you again when the chicks have left the colony and the adults are returning fat and healthy to begin their annual moult (molt)..
Best wishes, Mike
Dear Penguin Promises
The weather in the colony has turned really cold, and it has been no fun at all for Promises standing in the freezing cold wind for weeks with half the feathers missing. But now the moult (molt) has finally come to an end and the penguins look really smart in their new shiny black and white plumage.
The end of the moult means that Promises can now set off on the winter migration, which is without doubt one of the best times of year for the penguins. Penguins love being in the water, and they only come ashore when they have to. Because they are birds, penguins are forced to carry out certain parts of their life-cycle on land, such as egg-laying and chick-rearing, but when not forced to come ashore, penguins remain at sea 24/7. No other bird is so well adapted to life at sea, and no other bird can remain at sea for such long periods of time as penguins.
A few days ago Promises left the colony to begin the winter migration. A few penguins still remain here in the colony, but they will also leave during the next few days and the colony will then remain deserted until late September. Having left the colony, the penguins gradually make their way up the coast of Patagonia without ever coming ashore at all. They remain in the sea throughout the day and the night, and even sleep floating in the water.
Penguins lay their eggs and raise their chicks in the extreme south during the summer months, because this far south the days are very long for catching fish, with almost 20 hours of daylight per day during December and January. Now that winter is approaching it gets very cold, with snow, and the days are very short and gloomy. These are not good conditions for raising chicks, so instead the penguins migrate northwards and wait until the weather gets better again before returning to the nest to lay more eggs.
You may wonder why the penguins don’t just remain further north to lay their eggs, instead of travelling all the way back home. The reason is that nearer to the South Pole (and the North Pole too) the days are much longer during the summer than anywhere else on Earth. The equator has hotter weather, but much less difference in daylight between winter and summer, and hence shorter days in summer. The long daylight in summer has two advantages for Promises.
Firstly, as already mentioned, the long hours of daylight allows the penguins to spend up to 20 hours a day catching fish for the chicks. Further from the poles the days are not so long during the summer, so the chicks would receive less food each day if they lived further north.
Secondly, close to the South Pole the virtually constant daylight causes a bloom of microscopic aquatic plants. These microscopic plants only need sunshine to grow and multiply rapidly, and the longer the daylight, the faster they grow. This bloom of microscopic plants in turn causes an explosion of krill and other ocean creatures that feed on the abundant algae. Fish gather in huge quantities to catch the krill and aquatic creatures, and penguins, whales and dolphins move south to take advantage of the large fish and krill populations that gather.
This is called a Food Chain. The extremely long hours of daylight in summer causes a chain reaction that begins with the rapid growth of microscopic plants, and ends with the migration of whales from as far away as Hawaii and Alaska.
Penguins are just some of the animals that migrate long distances to take advantage of this abundance of food during the southern summer. Sand Pipers and other small shore-birds migrate from the northern hemisphere to the southern hemisphere in order to enjoy two summers every year. Whales and dolphins also migrate long distances in order to spend the summer around the South Pole. Compared to whales and Sand Pipers, the penguins’ migration is quiet short.
Ocean currents run up the coast of Patagonia, so that helps Promises travel northwards more quickly. Of course, that same current means that the penguins will have to swim harder when coming back home later in the year. They usually spend the winter off the coast of Brazil, but they have no particular destination in mind.
Because they never come out of the ocean, one part of the coast is much the same as another to the penguins. They only ever see Brazil from a distance. The only penguins that come ashore in Brazil are a handful of penguins that get sick or injured, or which suffer from oil contamination. There are several rehabilitation centres in Brazil that rescue such penguins when they are found on the beaches by concerned sun-bathers. This is virtually the only time that people living in Brazil ever get to see the penguins. The penguins usually remain too far offshore to be seen from the coast.
Penguins are very social animals and they remain together in groups. Penguins like the company of other penguins, but they do not remain with their partner during the winter migration. This is not because of any deliberate desire to separate during the winter. It is just that out at sea it is almost impossible to maintain contact with individual penguins.
On land it is easy to see a long distance, but out in the open ocean a penguin can only see a short distance. The Atlantic Ocean is not like a swimming pool. It has too many tiny particles suspended in the water to see more than 30 or 40 metres at the very most. The distance at which one penguin could identify another penguin underwater amongst all the other penguins is very short indeed.
On the water surface the distance that penguins can see is even shorter, as you can see from the attached photo. Penguins are very low in the water, so they can only see as far away as the next wave. Anything beyond that is hidden behind the waves. When they are momentarily lifted up by a passing wave penguins can get a better glimpse of their surroundings, but most of the time penguins cannot see very far at all in the open ocean.
When penguins catch fish they often have to chase them for quite some distance before they catch them. After such a chase it would be almost impossible to find an individual penguin that was left amongst all the other penguins, so pairs do not even try to remain together. It would be an impossible task.
Penguins keep together in groups during the winter migration, but these groups are made up of random individuals, because it is impossible for penguins to keep track of individual penguins out at sea. Whales and dolphins do remain together as families, but they are much larger and fewer in number, making it easier to identify individuals. Whales and dolphins also use sound to communicate over long distances. Penguins have never developed that ability, perhaps because their bodies are too small to produce such powerful underwater sound waves.
When the penguins return to the colony at the end of their winter migration, the males arrive a few days before the females and wait for their partner at the nest. Magellanic penguins are faithfully to their partner and to their nest. In the same way that we return home to reunite with our family at the end of the day, so too the penguins return to their home to reunite with their partner,
albeit after many weeks. This also enables us to locate and follow Promises year after year. We just call round when they are at home, just like we do with family and friends.
I will write to you again in a few weeks time, by which time the penguins will be somewhere off the coast of Brazil enjoying the sunshine. So whilst we await the return of Promises, I will take the opportunity to share with you the results of our penguin research the next time I write
Best wishes, Mike