Penguins:

Dating back 61 million years ago, the penguin's closest evolutionary relative is surprisingly, long-distance fliers including the petrel and the albatross.  Unlike the hollow bones these birds possesse, penguins have solid bones that allow for submerging deep into the icy waters of their environment. With reduced air spaces in their skeletons, along with increased bone wall thickness, and the ability to store more oxygen in their muscles, penguins are efficient divers. Other contributing factors to their swimming ability include: huge fat supplies, heavy muscles, and densely packed feathers. 

 

Penguins naturally exist only in the southern hemisphere, with only one species existing above the equator on an island in the Galapagos.

 

 A penguin's vision has been adapted to allow them to see in low light, and underwater. They have a 3rd eyelid called a 'nictitating membrane' that protects their eyes while they swim underwater, essentially offering a sort of goggle to the eyes. Aiding their "flight" through the water is a gland that produces waterproof oil that penguins apply to their feathers. They spend a great deal of time applying it to their feathers before entering the water!

 

Penguins' diet preferences vary depending upon species, so there is no competition for the same food. While penguins have special genes to help them detect salty and sour tastes, they cannot detect bitter, sweet or savory tastes.  In order to prevent slippery prey from getting away, penguins have backward facing keratin spikes on their tongue. Since their diet consists of food flush with salt, they have a special supraorbital gland near their eyes that filters excess salt from their systems.

 

Penguins are highly adapted to walking on land with their feet, and Emperor penguins are known to walk, waddle, and toboggan 100 km to reach their breeding grounds. Once the sole egg from the female is laid, the male Emperor penguins take responsibility for keeping the eggs warm during the tough winter months in Antarctica. There is a significant loss of body weight for the fathers, as there is no food source nearby. If chicks hatch before penguin moms return, the fathers are able to regurgitate a curd-like substance to feed the chicks until their moms do return. The parents hand off the care of the chick and males make the long journey back to the water to finally eat again. The chicks must make their way to the ocean on their own. Luckily penguins are good at creating mental maps, even when they have never left the nest before.

 

Another species, the Gentoo penguins, 'gift' each other shiny, ocean-smooth rocks. The males begin wooing a female, and if she is interested, will find a pebble to give back. Eventually these pebbles will become a nest for the two of them to raise a family. The rocks also allow ice and snow to melt through the nests, especially when they are built upon a slope. 

 

The animal kingdom offers natural protection to blend into their environments, and avoid detection by predators. The countershading of the black and white color of the penguin allows them to blend into the dark water if viewed from above the water, and the surface from below.

 

What do you call a group of penguins in the water? While the answer is a 'raft', it is different from a group of penguins on land, which is a 'waddle'. Perhaps the term refers to how they maneuver on land? 

 

Besides having quite the speed in the water, and the endurance to traverse long distances on two feet, penguins have the ability to leap up to 9 feet.