Looking at a penguin standing or waddling around on the island it may look like they have very short legs and no knees.



But yes, penguins do have knees!

A penguin’s leg is composed of a short femur, knee, tibia and fibula. The upper leg bones are not visible as they are covered in feathers giving penguins a very short legged appearance. Here you can compare the leg of a penguin skeleton to a model of a human skeleton.





Take at look at these x-rays of one of our penguins and you can see the leg bones, including the knee joint and how most of it is covered in the penguin’s body.


Head-on x-ray of penguin, the knees are in green rectangles


Side-view of penguin knees in yellow rectangle

So now you know!

- Andrea

As mentioned before in this previous post, penguins molt their feathers every year. This process takes about 2-3 weeks. As they approach the end of the molt it is exciting to see the interesting patterns the last remaining patches of old feathers make.



Here are some fun looks from our penguins.


The mohawk


The lion's mane


Horns


Spikey


The Beard

Once the penguins complete their molts, they have slimmed down to their original weight, have a brand new set of feathers and are ready to face the cold ocean water until next year, when they start the process all over again.


Just three old feathers left and a shiny new set of feathers


All done and showing off new feathers!

We'll be posting a video of our rockhoppers in the middle of their molt very soon. Stay tuned!

- Andrea

A penguin's feathers are very important for keeping them warm and dry while they are in the cold ocean water. Over time their feathers may wear and break (imagine wearing a sweater everyday for a year, it is bound to get some holes in it, and look a little worse for wear). In order to replace these feathers, penguins go through what is called a molt, where their old feathers are pushed out and replaced by new ones.

A penguin's molt is sometimes called a catastrophic molt, because unlike most birds that will molt a few feathers at a time, penguins molt all of their feathers all at once. And if you look at some of these pictures you can see that catastrophic is a good description, they often look like exploding pillows.


An exploding pillow!

Molting is a 3 stage process and starts weeks before the penguin actually replaces any feathers. Their bodies are making the new feathers while they are gorging themselves on fish which they must do to increase body weight to endure the 2nd stage. Penguins are not waterproof when they molt, so in stage 2 they stay on land for 2-3 weeks fasting until the new feathers have emerged from below the skin. During that time they will not eat, so a few weeks prior to the molt they will increase their food intake to build up a fat reserve to live off of while they are on land. Since we record how many fish each penguin eats everyday we can usually recognize when a penguin is getting ready to molt since their daily food totals can double or even triple. In the wild stage 3 involves returning to the sea to replenish lost body weight.

Here are a few pictures of some of our penguins right before they start molting, notice how much bigger they look than a normal penguin.


An normal African penguin


A penguin getting ready to molt


A normal-sized rockhopper penguin


A rockhopper pre-molt

In this photo you can see the wings of two penguins; the one on the right is just about to start molting.



Can you spot the fresh new feathers coming in?

Stay tuned for more pictures and video as our penguins complete their molts.

- Andrea

This is Lion. He is a little blue penguin and has an orange bracelet on his left wing.


Lion

Lion is named after Lion Island which is the largest little blue penguin breeding island near Sydney, Australia. The island gets its name because its shape resembles the mythical creature, the sphinx. Lion Island was protected in a nature reserve in 1967. It is an ideal little blue breeding habitat because it is free of feral cats and foxes, which are introduced predators of little blue penguins.

(We'll have more about introduced predators in an upcoming blog!)


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Lion was born here at the Aquarium on April 14, 2008. While all penguin births are special to us here at the Aquarium, Lion’s was a very special case. Lion’s egg was overdue to hatch. We made the decision to try to help the chick inside hatch out by manually opening the shell. When Lion was finally hatched out we returned him to his parents. Unfortunately, for whatever reason, his parents rejected Lion and would not care for him. In order for Lion to survive we had to step in.

Lion required around the clock care (not unlike a newborn baby). This required Heather and Caitlin to take him home each evening to feed him and make sure he stayed warm. Once he was older and was fed on a more normal schedule (3-4 times a day, instead of every 3-4 hours) he remained at the Aquarium with other little blue penguin chicks that were born that season, until he was introduced into the exhibit on July 16, 2008.




Lion at home with Heather

This heartwarming story of Caitlin and Heather literally taking their work home with them caught the media’s eye. And for weeks Lion’s story was in the newspaper, and on the local news. Lion, Heather and Caitlin even appeared on CBS's The Early Show. Click on the following news links to see more of Lion's 15 minutes of fame!


Watch CBS News Videos Online

Visit msnbc.com for breaking news, world news, and news about the economy

There's more from MSNBC here. The Associated Press also put together a beautiful slide show narrated by Caitlyn.

- Andrea