Inside The World of Penguins
There are 17 species of penguins some of which are found as far north as the equator. Penguins are categorized into three families: brush-tail, crested, and king/emperor penguins. Of the 17 species only six are found in Antarctica (Adélies, Chinstraps, Emperors, Gentoos, Macaronis, and Rockhoppers). Penguins often are referred to as "flippered flyers" due to their effortless movement through the water and their possible evolution from gull-like birds. It’s believed that 40-50 million years ago, while Antarctica breaking away from Gondwanaland, penguins also were separating to form their own species. Originally, indigenous to warmer climates, penguins adapted to the cold as Antarctica made its move southward. Part of their adaptation to the cold includes oily, unwettable feathers which cover the outer layers of penguins. Underneath is a layer of soft down feathers and under that a thick layer of fat. This keeps the penguins so warm they will actually fluff their feather to released trapped heat in order to cool down. In addition to their fine attire, penguins are well known for their swimming abilities. Using their flippers for propulsion and their feet as a rudder, penguins can swim in excess of 12 mph. Through the use of air sacs to protect their lungs, penguins can stay under water for 15 to 20 minutes and dive as deep as 275 feet. In the water, penguins typically feed on krill and fis. Krill eating penguins excrete pink guano, while those eating fish leave behind white guano. The yolks of penguin’s eggs often are red denoting the consumption of krill. Although very near-sighted on land, penguins posses exceptional vision in the water. Their eyes, like the many sea animals, are attuned to the colors of the sea-green, blue-green, and violet. They need this excellent vision to avoid leopard seals and killer whales, which are their primary predators in the ocean. On land their arch enemies are skuas, large birds, which snatch penguin chicks from nests.
Adélie Penguins
Adélies are relatively small birds standing on average 27.5 inches high and weighing 10-11 pounds. During the harsh winter months they stay near the outer edges of the pack ice where temperatures are slightly warmer. As summer approaches, they migrate towards the continent and form rookeries ranging in size from under a hundred to hundreds of thousands. Males arriving first attempt to reclaim old nesting spots. Females are presented with pebbles as gifts during the courting process. Adults surviving from one year to the next often mate again. However, this marriage is not permanent; pairs typically separate after five or six years. Immediately after laying her one or two eggs, the female heads for the open sea to replenish her food storage. The male incubates the eggs for the first 10-15 days while the female is away. Upon her return, the male spends 10-15 days at sea fatten up. The male eventually returns to take the final shift of 3-7 days. During the whole courtship and incubation period, mates will lose up to 45% of their initial body weight. Chicks stay with their parents for approximately three weeks during which they grow rapidly. After that, they join the other chicks in nurseries called créches. At that time, both parents go to sea to feed. This is the most dangerous time for a chick, skuas circling above continuously raid the nursery for fatten chicks. After four weeks of age, the chicks head for the sea. By late February, the colonies are abandoned.
Chinstrap Penguins
Chinstraps get their name from the thin line which circles from behind one eye under the chin to behind the other eye, much like a strap on a helmet. They are the same approximate size as Adélies. Chinstraps appear to prefer slightly warmer waters, only breeding among the islands off the coast of the Antarctic Peninsula. One of the largest colonies, Bailey's Head, is located on the side of a currently dormant volcano called Deception Island. Chinstraps