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Jasmin Strong

Galapagos Pinniped Expert

Penguins on the Equator?

Galapagos Penguin.  Illustration by Jasmin Strong.

Usually when you hear the word penguin you think of these flightless, sleek, black and white birds in the cold tundra of Antarctica. However, penguins don’t only reside in the uninhabited continent which hosts the South Pole; they can also be found all across the southern hemisphere in South Africa, New Zealand and South America. Believe it or not, penguins can even be found across the infamous archipelago, the Galapagos Islands. The Galapagos penguins (Sphenciscus mendiculus) have found a home among the blue-footed boobies and the infamous finches. But for how long? Despite their many adaptations to survive in the harsh climate, they aren’t thriving. Even though their population numbers are slowly increasing, they still have an alarmingly low population number and are listed as an endangered species. So, what exactly is causing the population decline seen in these Galapagos Penguins?  

The Galapagos penguins are marvelous creatures. During my time in the Galapagos we saw them on the coast of Isla Isabela and while snorkeling off the coast of Isabela. Although seeing them relaxing on the lava rocks was exciting, you would be really lucky if you spotted the penguins in the water. Diving for their next meal, the creatures had looked like a black and white flash. Sometimes they were so quick it would take you a second to register what you had just saw. The tiny creatures are the third smallest penguin in the entire world and are smaller than their other temperate counterparts. Their average body height is only a mere 53 centimeters. That’s only three inches taller than an average newborn baby. The Galapagos penguins reside closer to the equator than any other penguins and are found on the younger, western islands of the Galapagos, most notably Fernandina and Isabela [1].  As an extremely social species, the Galapagos penguins are usually seen with at least one other companion. Dr. Robert Rothman, a professor at Rochester Institute of Technology, once saw about 200 penguins together at Elizabeth Bay on Isabela [2]. Two hundred penguins may not seem like a large amount when comparing it to the colonies of penguins that can be seen in Antarctica, especially when studies exist that estimate population sizes of Emperor penguins as high as 27,114 members[3], but 200 is a large population in relation to the Galapagos penguins. This shows how the number of penguins in the Galapagos is significantly smaller than in other areas containing penguins. Although during my time in the Galapagos I wasn’t fortunate enough to see 200 penguins, I never did see any penguin alone. However, even these populations of 200 penguins may not last long. Sadly, the Galapagos penguin has recently found iteslf on the list of endangered species, with an estimated population of less than 2,000 members found across the archipelago[4]. Although they have made the Galapagos their home, it is possible that many aspects of the Galapagos islands’ difficult environment contribute to this growing issue.

Life in the Galapagos is not easy. Species across the archipelago have adapted to survive in the ever changing environment. The rough volcanic terrain, lack of fresh water, intense sun and heat, are the major problems that species need to account for in order to survive. Not to mention how resource availability is extremely unpredictable in the Galapagos, as well. The El Niño events also greatly impact the species in the Galapagos. El Niño ruins the cold currents by bringing in warm currents and drastically reducing the upwell of the cool Equatorial current affecting the productivity in the Galapagos.[5] In many cases, El Niño has proven to dramatically drop population numbers of many Galapagos species.

The first time I caught sight of the creatures I couldn’t help but wonder what made an animal that is commonly found in cold environments capable of surviving in the sweltering heat of the Galapagos. The penguins supposedly followed the Humboldt current from Antarctica to Galápagos. This current is a characteristic of the Galapagos that leads to its productivity and unique wildlife, as well an aspect that allows the penguins to reside in the islands. The cooler temperature of the water due to the current enables the penguins to beat the heat. This current also accounts for the fur seals in the Galapagos.[6] It is the reason why typically cold-climate animals can still find a place among the tropics of South America.

The temperature and intensity of the sun is a factor of the Galapagos that the penguins must adapt to, as well. Being in the equator, the sun is more intense than anywhere else on earth. This is a part life that Antarctic penguins and even some of the other temperature penguins don’t have to deal with. Many of the adaptations to deal with these aspects of the Galapagos are behavioral. Therefore, behavior is another source of differences between the Galapagos penguins and the Magellanic and Humboldt penguins, their temperate counterparts. The penguins will dive and forage during the day when the heat and sun is the most intense [7]. All their dives are also close to the surface and shore, so they have time to take a short break on the shore, allowing them to dive more frequently.

Another one of their unique common behaviors has to do with their feet. The Galapagos penguins will stand with a hunched posture in order to shade their feet from the sun. Additionally, the penguins will often stand with their flippers out, in a similar way the flightless cormorants spread their wings so their wings will dry, in order to help them lose heat faster [5]. Just like huddling together to keep warm is important to penguins in Antarctica, finding effective ways to remain cool is imperative to the Galapagos penguins.

The Galapagos penguins also have many physical adaptations. The first and most notable adaptation is their general size. As mentioned earlier the Galapagos penguin is very small as penguins go at only 53 centimeters tall. As one of the smallest penguins in the world, the Galapagos penguins have figured out how to deal with the unpredictability of the productivity in the Galapagos. Body size is thought to be important information when determining resource use patterns [8]. In other words, the smaller they are the less resources they need and the more likely they are to survive the dry periods when production is incredibly low.

This unpredictability also influences the breeding habits of Galapagos penguins. Where most penguins have one particular breeding season, the Galapagos penguins will breed two to three times a year. Reproduction and the growth and molting of the new penguins are two of the most energy-intensive activities the Galapagos penguins do. Thus, breeding will usually occur in when the conditions are favorable, like when the surface temperature is the coolest and productivity is at its peak [9]. The fact that there isn’t a uniform breeding season also leads penguins to be monogamous so they can breed right when conditions are favorable [10].

 As previously mentioned the number of Galapagos penguins are dwindling. And with small populations comes lack of genetic diversity. The observed heterozygosity, a measurement conducted to see how diverse a population is, is only at 3%. This is incredibly low not only in comparison to the other temperate penguins, such as the Magellanic penguin, but also just in general [1].  Its population size is also much smaller and less stable than that of the Magellanic penguins. The Magellanic penguins, also known as the Patagonia penguins, are found on the eastern and western coasts of southern South America, specifically heavy in Argentina, meaning that the effects of El Niño and other Galapagos hardships aren’t felt by them. The differences seen between the population sizes, genetic diversity, and behavior can aid in understanding to what extent living in the Galapagos affects the Galapagos penguins and separates them from not only penguins around the world but also temperate penguins.

The low population sizes can be attributed to the El Niño events that greatly impact the Galapagos islands.  F. Herńan Varags from the University of Oxford explains that “historic El Niño episodes are likely to have shaped specific breeding and survival strategies in this species” [11]. However, past El Niño events have dramatically affected the population size of the penguins despite all their adaptations. Boersma, a conservation biologist at the University of Washington, says that the current population of Galapagos penguins is only 25% of what it was in the 1970s and that much of this steep decline is due to two separate El Niño events, one in 1982-1983 and the other in 1997-1998[12]. Also female penguins are more likely to die, reinforcing low population sizes due to lack of reproduction. As previously mentioned the Galapagos penguins won’t reproduce under bad conditions, so there will be seasons where they don’t reproduce at all [9]. Widespread death and lack of reproducing only goes to further limit the genetic diversity of the penguins.

It is predicted that El Niño events are becoming more severe and intense, due to climate warming [11]. The 2015 El Niño is commonly referred to as the “super” El Niño and thought of as the worst one to date, only powering hypotheses that climate change is negatively affecting El Niño and in turn the Galapagos wildlife. Even, worse news, it’s estimated that there is a 30% chance of the extinction of the Galapagos penguins in the next 100 years and that’s if the El Niño events don’t get worse. If we don’t do something to address our global warming, we could lose a lot of the unique biodiversity on this planet. Humans directly affect the Galapagos penguin population by over-fishing and thereby taking away the sardines and mullets, major food sources for the penguins [10]. It’s necessary that we realize how deeply human influence affects the environment and the rare species of the world. It’s pretty easy to see what is happening to these penguins, and it is important that we take action in order to help ensure that penguins stay in the Galapagos.

[1] Akst EP, Boersma PD, Fleischer RC (2002) A comparison of genetic diversity between the    Galapagos Penguin and the Magellanic Penguin. Conserv Genet 3:375–383

[2] Rothman R. (2002) Galapagos Penguins. Galapagos @ RIT.

[3] Fretwell PT, LaRue MA, Morin P, Kooyman GL, Wienecke B, et al. (2012) An Emperor Penguin Population Estimate: The First Global, Synoptic Survey of a Species from Space. PLoS ONE 7(4):

[4] World Wildlife Fund. Galapagos Penguin (2017).

[5] Karnauskas K. (2015). El Niño and the Galápagos.

[6] Smith J. (2012). Galapagos Ocean Currents. Khaled bin Sultan Living Oceans Foundation.

[7] Encyclopedia of Life. Spheniscus mendiculus Galapagos Penguin. EOL

[8] Saporiti, Fabiana et al. Resource Partitioning among Air-Breathing Marine Predators: Are Body Size and Mouth Diameter the Major Determinants? Marine Ecology 37.5 (2016): 957–969. Wiley Online Library. Web.

[9] Boersma PD (1978). Breeding Patterns of Galapagos Penguins as an Indicator of Oceanographic Conditions. Science 200:4349. 1481-1483.

[10] Wahlstrom, J. 2007. Spheniscus mendiculus (On-line), Animal Diversity Web.

[11] Vargas FH, Harrison S, Rea S, Macdonald DW (2005). Biological effects of El Niño on the Galápagos penguin. Biological Conservation. 127: 107-114

[12] Boersma PD.(2008) Penguins as Marine Sentinels. BioScience. 58(7): 597-607