Why Aren’t There Penguins Everywhere?
Of the 17 species of penguins that exist today, all are found in the Southern Hemisphere. Most populations live in Antarctica, but penguins can also be found in South America, South Africa, Australia, New Zealand and many small islands in the south Pacific Ocean (and, in captivity, at your local zoo or marine park). It is not known why there are no penguins in the Northern Hemisphere but it is clear that, due to climate change and human development, penguins’ numbers are declining worldwide.
Climate Change Threatens Penguins
A 2008, report from the World Wildlife Federation found that 50 percent of emperor penguins and 75 percent of Adelie penguins are likely to decline or disappear if global average temperatures rise by 2 degrees Celsius (about 3.6 degrees Fahrenheit) in the next 40 years. These penguins depend on the sea ice for food and for breeding, so their existence is highly threatened due to rising temperatures. Ecologists have found that, with the sea ice melting and cracking, emperor penguins do not change their habits, but nest in the same places. As a result, their eggs and even some adults have been crushed by moving ice. Some have possibly died from exhaustion and starvation after walking distances across the ice from open water to their nesting colonies.
Other species, including the chinstrap penguin on the Antarctic peninsula, also face extinction due to climate change, based on data gathered in December of 2011 from Deception Island, one of the busiest tourist sites in Antarctica.
Human Factors Contribute to Decline in Chile’s Penguins
The warming of central Chile’s waters due to El Niño has made it harder for Humboldt penguins to find their accustomed diet. But the disappearance of thousands of penguins from the Pajaro Nino islet (about 75 miles west of Chile’s capital of Santiago) is not only the result of global warming.
Humboldt penguins nest only in parts of Chile (where they are now considered “vulnerable”) and Peru (where they have been designated “endangered”). Alejandro Simeone, director of the Department of Ecology and Biodiversity at Andres Bello University, estimates that fewer than 50,000 penguins remain in both countries.
In stark contrast to the droves of birds that local fishermen recall, only about 500 Humboldt penguins now nest in the islet. Simeone says the decline began in 1978. The islet is a nature sanctuary, but a cement fill-in was built that joined it to the mainland, to serve as a breakwater for million-dollar yachts. The resulting 500-foot bridge has been “detrimental” for wildlife and native plants.
Yachters, who apparently are not fond of the penguins’ excrement, have been filmed destroying their eggs. A 2012 study also found that, within twelve hours of the breeding period, about half of the penguins’ eggs were destroyed by rats who had traveled over the cement bridge to the islet. Older birds face an additional hazard in the form of fishermen’s nets.
Could Studying African Penguins Help Preserve Penguins Elsewhere?
A recently published study of the one species of penguin in Africa offers clues about why penguin diversity there “plummeted” dramatically and may offer clues about how to preserve today’s species. Today, only the black-footed penguin — also known as the jackass penguin for its loud braying call which resembles that of a donkey — lives in South Africa. Fossils found in 2010 by Daniel Thomas of the National Museum of Natural History and Dan Ksepka of the National Evolutionary Synthesis Center suggest that as many as four penguin species once lived in Africa. Their bones suggest they ranged in size from a “runty pint-sized penguin that stood just about a foot tall (0.3 m), to a towering species closer to three feet (0.9 m).”
Humans had not yet arrived in South Africa when these prehistoric penguins became extinct. Rising sea levels that wiped out safe nesting sites are most likely to blame, says Science Daily:
Land surface reconstructions suggest that five million years ago — when at least four penguin species still called Africa home — sea level on the South African coast was as much as 90 meters higher than it is today, swamping low-lying areas and turning the region into a network of islands. More islands meant more beaches where penguins could breed while staying safe from mainland predators.
Now sea levels in the African penguins’ habitat have again fallen and left land bridges recently exposed. As a result, islands that were once isolated are now connected to the mainland, giving predators access to eggs and eliminating nesting sites.
The black-footed penguins’ numbers have fallen by 80 percent in just the past 50 years. This time around, human activity is playing a part: oil spills have reduced the black-footed penguins’ numbers and overfishing has diminished supplies of their favorite foods, sardines and anchovies.
“There’s only one species left today, and it’s up to us to keep it safe,” as Thomas says of Africa’s sole surviving penguins. His words also resonate in regard to the penguins of Antarctica, Chile and Peru: one day, the reason why penguins can’t be found everywhere may well not have anything to do with their being uniquely suited for certain marine ecosystems, but because we humans have, indirectly and indirectly, inexorably changed the places they long called home.
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