Penguins and other birds
Roughly how old do Emperor penguins live?
Emperor penguins live 20 to 25 years. They can start to breed when they are three years old, although many will not breed until the sixth year. Remember that a single egg is laid in March to April at the start of winter and the male parent incubates the egg for around two months when it hatches. The male feeds the penguin from its own reserves for a further 50 days when the female parent returns from a long time feeding at sea. By this time the male has lost around half its body weight and he returns to sea for feeding. This must be a stressful time for parents and chick alike.
Is the population of penguins declining?
Some penguins are declining, for example the Rockhopper, while others are staying the same. The reason for the decline is not exactly understood but people are studying the decline. It may be linked to overfishing.
How old are the Emperor penguin chicks when they start to swim and feed themselves?
Emperor penguin chicks go to sea in December. They are still covered in down. They would have made their first appearance (still inside an egg) in April, hatching in June, being fed by the father in July and August, and by the mother again in September. Later both parents feed the chick for the rest of the winter.
What fraction of penguin chicks survive?
Quite a small fraction. Most years penguins may have one or two eggs, and the life expectancy of adults is 15 years. These penguins live in colonies that are not increasing in size so we can see that it takes around 15 to 30 penguin eggs to produce two healthy adults. Thus the survival rate is about 1 in 7 to 1 in 15. 6% to 14%. Most penguins who fledge die during their first year at sea away from the colony where they were brought up. A combination of events lead to their mortality. Inexperience of feeding for oneself, and being "snapped up" by killer whales and leopard seals are probably the most important.
Have you ever seen penguins attack a whale?
No. Whales have no fear of penguins and penguins do not hunt in packs. Adult penguins get enough food without having to be jealous of the whales and they are very well adapted to recover their own food themselves.
What types of animal habitat did you see?
I'm not sure what you mean here. Mainly, the island is composed of rocky beaches - where the fur seals haul out onto the land. Then there are some rocky outcrops where the gentoo penguins seem to stay. The macaroni penguins seem to colonise fairly steep rocky cliffs. Much of the island is covered in tussac grass - big lumps of grass. The fur seals like to go further up the slopes to the grass later in the season. The albatrosses nest in among the higher parts of the tussac - preferring the steep parts (possibly to get away from the seals). Then some of the smaller birds nest in cracks in rocky cliffs or in holes in the shingly ground higher up the peaks.
What was the biggest flying bird you saw?
Definitely a wandering albatross - these have wingspans up to 3.2 m long!! They are huge - and on land are a bit reminiscent of a giant turkey.
How do penguins manage to swim in the freezing ocean and still survive?
When penguins swim they generate lots of heat and so it probably isn't as big a problem as we would think. However they're very good at isolating the middle of their bodies and keeping that part of them warm, even though the water is cold (about 2-3 degrees around Bird Island).
What size is a penguin compared to you? I am 133cms tall.
Different kinds of penguins reach different sizes. A macaroni penguin is about 55 cm, a king penguin is about a metre high. Imagine that - a king penguin would almost be as tall as you!! (We have both of those on Bird Island). An emperor penguin is even bigger - probably about your size!!!
Are you very near to the places where the penguins live?
Yes - our base is about a 10 minute walk from a colony of gentoo penguins and a 25 minute walk from a huge colony of macaroni penguins.
What do penguins and seals eat and how do they get their food?
Mainly they eat krill, and they have to swim for their supper. They both swim out from Bird Island - the seals go about 100 km out - to get their krill.