Penguin Populations Decreasing
Are These Wild Birds Indicators of Climate Change?
Penguins are extremely specialized wild birds that have usually adapted to the environment and survived during their long history on earth. Now scientists are concerned because as penguins have to travel further and dive deeper to find food, their populations are shrinking.
Penguin History
Penguins have been traced back around 50 million years with the first fossil, now in the Museum of Natural History, found in New Zealand in about 1849. Some believe that Portuguese sailors discovered the South African Blackfooted penguin in the 1480s. Many extinct species have been discovered with penguin fossils being found in Australia in 1889, Argentina in South America in 1891, on Seymour Island, Antarctica in 1903 and in South Africa in 1970. While most were the same size as those found today, two species stood over 5 feet tall and weighed as much as 300 pounds. The name “penguin” was first given to a bird that is now called the Great Auk, a large flightless bird with black and white markings.
Penguin Species and Habitats
Penguins are usually divided into 6 groups that contain 15-18 species although not everyone agrees on the number. The groups include the Emperor, King, Brush-tailed, Warm Weather Crested, Yellow-eyed and Fairy penguins.
Only two species live on the Antarctic continent while others are still found on the shores of South America, South Africa, Australia, New Zealand and Galapagos Islands. Some species of penguins live three-quarters of their life at sea, only coming to shore to breed and molt. Migratory birds will spend 3-5 months at sea and spend the rest of the time on ice floes. Although penguins have no large land predators, while in the ocean they are preyed upon by killer whales, leopard seals, sea lions, sharks and perhaps octopi. Because of their very dense feathers and blubber, cold weather penguins are well insulated against drops in temperature. Warm weather penguins have exposed areas of pinkish skin that helps to keep them cool.
Penguin Shrinking Population
Penguins depend on a certain type of fish to survive. Now they have to travel further and dive deeper for food. While this can be blamed on a changing climate, over-fishing is also having an effect on penguins. Dr. Lewis Halsey of the University of Birmingham continues to do research to determine why the penguin population is shrinking. Biologist Rob Crawford, a penguin expert with South Africa’s Environmental Affairs Department believes the drop may be due to the scarcity of sardines and anchovies around penguin colonies which could be the result of over fishing or larger environmental changes.
There are also theories that because of the higher temperatures in Antarctica , penguin populations have been forced to migrate south, reducing the availability of krill that serves as the basis of the Antarctic food chain.
Penguin disappearance is providing evidence for the belief that the birds are facing a gauntlet of environmental challenges, from climate change, commercial fishing, pollution and even tourism. If this is true, penguins will go extinct before their time.
Sources:
Halsey, Lewis. Pick Up a Penguin. University of Birmingham, School of Biosciences.
Kaplan, Matt. King Penguins Declining to Global Warming. National Geographic News, February 2008.
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