Why Aren't There Penguins in the Arctic? FreeSchool Presents a Closer Look at Arctic Penguins

Let's start by getting one thing straight. There are no penguins in the Arctic. But doesn't it seem like there should be? Antarctica has ice, the Arctic has ice. Antarctica has oceans, the Arctic has oceans. And after all, there are multiple direct routes from Antarctica north to the Arctic for a bird with the prodigious swimming skills of a penguin. So what gives? Why haven't penguins ever moved north of the equator? To confuse the issue even further, it turns out that people have deliberately introduced penguins into the Arctic on no fewer than two separate occasions. Before we get to that, though, let's investigate the reasons that penguins haven't found their way to the Arctic on their own. Reason number one. Penguins don't like to get hot. You might think that living around the Antarctic, penguins would worry most about staying warm. However, penguins have a highly efficient system of insulation, combining fat and dense interlocking feathers to trap heat incredibly effectively. Most penguin species have to spend more effort keeping cool than keeping warm. How do they keep cool? Penguins will get in the shade, hold their flippers away from their bodies to release body heat, pant, or, of course, climb into the nice cool water. Species of penguins that live in warmer climates will even have bare patches of skin that make it easier to get rid of extra heat. Some scientists believe that the answer is as simple as the fact that water is warmer around the equator. Too warm for penguins to be comfortable. Therefore, they simply never swam through it. Hold on, you might say, if you are particularly knowledgeable about penguins. There are already penguins living at the equator. And of course, you would be right. The Galapagos penguin has the distinction of being the only penguin species to live technically in the northern hemisphere. The Galapagos islands straddle the equator, with parts of them being in the northern and the rest being in the southern hemisphere. Penguins that live in the northern Galapagos do live in the northern hemisphere, and all of them live at the equator. So that proves it, right? Penguins can live comfortably in equatorial waters. Not so fast! Let's take a look at this global map of average sea surface temperature. This spot right here is the Galapagos Galapagos. You can see that despite being located at the equator, the waters there are not as hot as those slightly farther north. That's because a cold Antarctic current, called the Humboldt current, flows north along the coast of South America, bringing nutrients that support a large fish population, and importantly, cooling the waters. The ocean around the Galapagos typically only gets to about 76 degrees Fahrenheit or 24 degrees Celsius, as opposed to the hottest equatorial waters, which often reach 86 degrees Fahrenheit or 30 degrees Celsius. If we take this a step further and place a map of penguin populations over the map of ocean temperatures, you will notice that there is a strong correlation between the edge of penguin territory and warm ocean waters. Since waters that exceed comfortable penguin temperature extend all the way around the equator, they form something called an equatorial thermal barrier, which, according to this theory, has prevented penguins from expanding northward. But if penguins have successfully adapted to the Galapagos and other warm places like Africa and Australia, is it really so unreasonable to assume that they could adapt again to even the warmest equatorial waters? Excellent question, and one that brings us to reason number two that penguins have not expanded farther north. In order to survive, penguins require habitat either on islands or remote areas without many land predators. This is because penguins move slowly on land. They also nest out in the open, and only lay one or two eggs at a time. Predators on land could quickly and easily wipe out a penguin population, either by preying on chicks and eggs, or by catching and killing adult penguins. Penguins apparently did not want to expand their range further up the coasts of South America, Africa, or Australia, but it's possible that suitable islands could have lured them farther north and through the equatorial thermal barrier. However, as you can see, these types of islands are few and far between in areas where these hot waters are the narrowest. All these factors together seem to adequately explain why penguins never made it to the Arctic on their own. Now let's turn to the real puzzle. Once they were introduced to northern shores, why did they fail to establish a population? Before we investigate that, let's go over what prompted someone to try moving penguins to the Arctic in the first place. If it seems like a cold-tolerant, fish-eating aquatic bird would do well in the Arctic, you're right! Meet the original penguin, the great auk. Native to the North Atlantic, great auks were black and white seabirds, growing up to 33 inches or 85 centimeters tall, and flightless. Even though they look very similar to penguins, they are not closely related at all. The resemblance was so strong, however, that when Europeans discovered penguins in the southern hemisphere, they named them for the auk's Latin name, pinguinus. The great auk was heavily hunted by humans for its meat, eggs, and warmed-down feathers. Under this pressure, their population dwindled over time until the last known pair was killed in 1844. Less than 100 years later, in the 1930s, scientists speculated that penguins from the southern hemisphere might be able to fill the ecological niche left open by the extinction of the great auk, as well as return the opportunities of hunting the large seabirds. In 1936, a team led by Carl Schoen of the Norwegian Nature Protection Society released nine king penguins onto islands off the coast of Norway. Two years later, another group released a batch of Macaroni and Gentoo penguins in the same area. Some of the penguins apparently survived and thrived for several years, even reportedly laying eggs and successfully hatching chicks. The last reported sighting of an Arctic penguin from these efforts was in 1954, nearly 20 years after the first ones were released. So what prevented the penguins from making a home in the Arctic? Likely the same thing that doomed the great auk, humans. Of the first nine penguins that were released, four were captured and killed within a year. At least one of the smaller penguins managed to survive for years, indicating that it could thrive in its new home, but was caught and killed by fishermen in 1944. Although it took 18 years, eventually all of the transplanted penguins were gone. It is likely a good thing that the penguins did not manage to establish a breeding population in the Arctic. Introducing new species into ecosystems almost always has unintended consequences, usually negative, for native wildlife. As cool as it would undoubtedly be to have penguins up north, it's best for everyone if they are left alone to live in the southern hemisphere.