Penguin

Penguins

Penguins (order Sphenisciformes, family Spheniscidae) are a group of aquatic, flightless birds. They live almost exclusively in the Southern Hemisphere, with only one species, the Galapagos penguin, found north of the equator. Highly adapted for life in the water, penguins have countershaded dark and white plumage, and their wings have evolved into flippers. Most penguins feed on krill, fish, squidand other forms of sea life caught while swimming underwater. They spend about half of their lives on land and half in the oceans.

Although almost all penguin species are native to the Southern Hemisphere, they are not found only in cold climates, such as Antarctica. In fact, only a few species of penguin live so far south. Several species are found in the temperate zone, and one species, the Galápagos penguin, lives near the equator.

The largest living species is the emperor penguin (Aptenodytes forsteri):^[1] on average adults are about 1.1 m (3 ft 7 in) tall and weigh 35 kg (77 lb). The smallest penguin species is the little blue penguin (Eudyptula minor), also known as the fairy penguin, which stands around 40 cm (16 in) tall and weighs 1 kg (2.2 lb). Among extant penguins, larger penguins inhabit colder regions, while smaller penguins are generally found in temperate or even tropical climates (see also Bergmann's rule). Some prehistoric species attained enormous sizes, becoming as tall or as heavy as an adult human. These were not restricted to Antarctic regions; on the contrary, subantarctic regions harboured high diversity, and at least one giant penguin occurred in a region around 2,000 km south of the equator 35 mya, in a climate decidedly warmer than today.

Taxonomic classification

Kingdom :	Animalia	Animals
Phylum :	Chordata	Vertebrates
Class :	Aves	This includes all birds.
Subclass :	Impennes	Swimming birds which have only rudimentary feathers
Order :	Sphenisciformes	This includes all living and extinct penguins.
Family:	Spheniscidae	It is the only family classification in the order Sphenisciformes.

Life Cycle

The penguins lay their eggs between July and October. They usually lay a single clutch of two eggs, but occasionally lay two clutches. Eggs are incubated for about 40 days. Chicks hatch between September and December.

Uniqueness of Penguins

1. Penguins lost the ability to fly millions of years ago, but their powerful flippers and streamlined bodies make them very accomplished swimmers. They are the fastest swimming and deepest diving species of any birds and can stay underwater up to 20 minutes at a time

2. Penguins’ eyes work better underwater than they do in the air, giving them superior eyesight to spot prey while hunting, even in cloudy, dark or murky water, or where water is turbulent.

3. The emperor penguin is the largest penguin species, standing up to 48 inches tall and weighing up to 90 pounds when mature and not fasting to incubate eggs. The little penguin is the smallest penguin at just 12 inches tall and weighing only 2 pounds.

4. The yellow-eyed penguin is believed to be the rarest penguin species, with only approximately 5,000 birds surviving in the wild, though population numbers fluctuate. They can only be found along the southeastern coast of New Zealand and smaller nearby islands.

5. Penguins are highly social, colonial birds that form breeding colonies called rookeries numbering in the tens of thousands. They may use the same nesting grounds for thousands of years and the largest colonies can number in the millions, with many penguins staying with the same mates for years. Parents and chicks use their superb hearing to easily keep track of one another even in a crowd.

6. Emperor penguins and king penguins do not make any sort of nests. Instead, a single egg for each mated pair is incubated on a parent’s feet and kept warm by a flap of skin called a brood pouch. Incubation can take 8-10 weeks and occurs during winter, so the egg must always be kept warm and safe.

7. Emperor penguin males incubate their eggs for two months in the winter without eating while the females are at sea. During that time, males live off their fat reserves and may lose half their body weight. When the females return shortly after the chicks hatch, they switch parental duties and the females fast while the males go to sea to replenish their fat stores.

8. Depending on the species, a wild penguin can live 15 to 20 years. During that time, they spend up to 75 percent of their lives at sea.

9. Emperor penguin males incubate their eggs for two months in the winter without eating while the females are at sea. During that time, males live off their fat reserves and may lose half their body weight. When the females return shortly after the chicks hatch, they switch parental duties and the females fast while the males go to sea to replenish their fat stores.