Skip to main content
All Posts By

Nataly H. Aranzamendi

Penguins of the past, what do we know about them?

relative large size of the Anthropornis penguin

Penguins of the Past – Prehistoric Penguins

by Nataly H. Aranzamendi

Millions of years ago, the world was a very different place from what we see now. Colossal giants wandered through planet Earth and many of them were quite different from the animals that remain today. However a group of flightless birds was already represented: the prehistoric penguins.

When did prehistoric penguins first appear?

George G. Simpson¹, an important paleontologist and geologist, classified ancient penguins in three groups: Palaeeudyptinae, Paraptenodytinae, and Palaeospheniscinae‎. He originally recognized about a dozen species, but since then there are new additions to the family tree of penguins nearly every year.

Based on previous DNA and fossil evidence, the possible dates for the earliest ancestor of penguins were originally calculated to date back 40 million years ago. However, recent evidence² has expanded those dates backwards and changed what we know about the presence of penguins. The oldest penguins might just date back to 60 million years ago during the early Cenozoic or late Cretaceous periods. This is 20 million years older than previously thought — and when dinosaurs were wandering the Earth!

relative large size of the Anthropornis penguin
Photo Credit: By Discott – Own work, CC BY-SA 4.0,

Did prehistoric penguins look like penguins of today?

The ancestors of penguins were slightly different from extant species. The oldest penguins probably had already lost their typical bird plumage, but their semi-rigid flipper — which helps them to swim in the ocean and gives them their hydrodynamic shape — was not totally transformed in all species.

An agreement among scientists seems to be the fact that there were some prehistoric penguins that reached big sizes. This was inferred from fossil records and particularly recorded for the oldest groups. For example, the largest fossil penguin was Anthropornis nordenskjoeldi, a penguin that could have reached almost two meters tall. This species lived around 33-45 million years ago. Another fossil found recently in New Zealand² was likely of a similar size as Anthropornis. Thus, big penguins were not uncommon. Nonetheless, a decline in body size occurred for the later groups³.

Two species of the genera Kairuku4 that lived in New Zealand in the late Oligocene (23-34 million years ago) depict some morphological differences between them and extant (currently living) species. Those penguins already showed the typical upright penguin posture, as well as long flippers and short, thick legs and feet. However, their bodies were much more slender than penguins of today and their bills much longer.

Prehistoric penguins lived in the same places as penguins of today

Prehistoric penguins shared the same distribution as their current relatives. They were found in the Southern Hemisphere including Antarctica. Fossil records of extinct penguins have been found in Antarctica, New Zealand, Australia, Argentina, Chile, Peru and South Africa.

Places where fossils were found show a relatively high penguin diversity, which possibly peaked at the late Eocene and early Oligocene. A high penguin diversity was probably related to the expansion of cold waters and the change in favorable conditions for diversification5 that followed the separation of continents from Antarctica.

In the late Paleocene, Antarctica and the surrounding continents were in very different geographic positions from where they are located today. Australia and South America were closer to Antarctica but increasingly shifted northwards and separated more and more from the frozen continent. Such events probably had a big influence in the biogeography of penguins. Isolation from the old continent and new climatic conditions most likely provided optimal conditions that made diversification of species possible.

Photo credit: JJ Harrison

However, continental species did not remain completely isolated, since DNA evidence has shown us that multiple independent dispersal events could have occurred. In Australia, for example, new species of penguins arrived to the continent at different historical times³. Besides the fact that Australia hosted several species of penguins, currently there is only one species left there, the Little penguin.

Based on the later example and extensive fossil record, it seems that penguin diversity was high everywhere but declined during more recent periods. Why penguin diversity plummeted is still a mystery although several factors could have contributed. Perhaps the appearance of potential competitors like cetaceans (dolphins, porpoises and whales) and pinnipeds (seals and sea lions) displaced them and/or deprived them of food. Another hypothesis is that environmental conditions continued changing and food became scarcer.

In any case, the constant exploration and finding of new fossils will probably keep increasing our knowledge of the penguin family tree. Similarly, the advancement of technology and improvement of data based on DNA analyses will keep providing information of the exact time when prehistoric gigantic penguins were wandering our planet.

Did you know all this about the history of penguins? Did you learn something new by reading this? Let us know what you think!


Also, read more about penguins in our other blogs:


1 Simpson, G.G. 1946. Fossil penguins. Bulletin of the American Museum of Natural History, 87 (1): 1-100, figs. 1-33. New York.

2 Mayr, G., De Pietri, V. L., & Scofield, R. P. (2017). A new fossil from the mid-Paleocene of New Zealand reveals an unexpected diversity of world’s oldest penguins. The Science of Nature, 104(3-4), 9.

3 Park T, Fitzgerald EMG, Gallagher SJ, Tomkins E, Allan T (2016) New Miocene Fossils and the History of Penguins in Australia. PLOS ONE 11(4): e0153915

4 Ksepka, D.T., Fordyce, R.E., Ando, T. and Jones, C.M. (2012). «New fossil penguins (Aves, Sphenisciformes) from the Oligocene of New Zealand reveal the skeletal plan of stem penguins». Journal of Vertebrate Paleontology 32 (2): 235-254

5 Acosta Hospitaleche, C. I. A., Griffin, M., Asensio, M., Cione, A. L., & Tambussi, C. P. (2013). Middle Cenozoic penguin remains from the Patagonian Cordillera. Andean Geology vol.40 no.3 set. 2013

Fieldwork with penguins: A fishy business

Fieldwork with penguins: A fishy business

by Nataly H. Aranzamendi

An island that smelled like fish

In 2007, I visited Ushuaia in south Argentina to spend some time learning about whales and seabirds. The view at the “end of the world” or Fin del Mundo as it is locally known, was breathtaking. This corner of the world where mountains meet the ocean, is a fantastic place to find occasional whales and seabirds circumventing marine waters.

Moreover, the surrounding islands in the Beagle Channel are excellent breeding places for Magellanic penguins. As soon as I heard that researchers were studying penguins nearby, I signed up for the adventure.

The day to visit the island finally arrived. We were three people including the main researcher. The first thing I noticed when disembarking was the strong smell of fish and guano that came from the island. It was the middle of the breeding season and fish was the main food item.

We settled our camp and started the hard work. Turns out that when daylight lasts for over 20 hours and there are hundreds of nesting penguins, work days can get pretty full. Our routine started around 9am and finished around 8pm. Every day we visited more than 60 nests.

Gentoo and Magellanic Penguins on the beach
Penguins on the beach near a penguin breeding colony.

First, some facts about Magellanic Penguins

Magellanic Penguins are birds that live in coastal Argentina, Chile and the Falkland islands. They are medium-sized penguins reaching 61–76 cm (24-30 in) tall, weighing between 2.7 and 6.5 kg (6 – 14 lbs), in which males are larger than females. They breed in underground cavities, where they generally lay two eggs. Incubation lasts 39–42 days, a task that the parents both share in 10- to 15-day shifts. The chicks are cared for by both parents for 29 days and are fed every two to three days1.

The purpose of our visit was to put GPS trackers on some parents to find out how far and how deep they go to find food. We also needed to record how many of the chicks will survive at the end of the breeding season. Generally, parents have two chicks but often only one survives2.

Magellanic Penguin with its chicks

What’s it like working with penguins in the wild?

Each person had his or her own task. We would slowly approach the nest and one of us (the most experienced one) would take the male, the second person restraining the female (if both present) while the third person dug in the nest to extract the chicks, measure them and mark them. All of us worked as fast as we could.

My first unexpected surprise was that parents were extremely strong. Their serrated bills, which are adapted to hold slippery fish, were a real danger for our hands. Since our major concern was always the penguins’ safety, we had to do everything as calmly but as fast as we could, so protecting our hands was not a priority. The second unexpected surprise was the penguins’ defense mechanism, which is called “defensive vomiting.”3

Defensive vomiting is a mechanism used by several animals to scare-off attackers or predators. We discovered that not only parents knew how to make us flinch, but the chicks also joined in on their vomiting act. After visiting the first two nests, I realized that this work was not for people with sensitive stomachs.

Magellanic Penguins in their burrow

Our three-day experience continued just like that. Since we were in a protected penguin sanctuary, there was no real accommodation for humans. The island belonged to the penguins and we had no facilities besides our tent to clean ourselves properly. Those were the “fishiest” days I had to endure in my entire life. Although it was summer, temperatures were close to zero degrees Celsius (32 F), so that was just one more factor restraining us from dipping in the ocean which looked more and more inviting the dirtier we got.

And those penguins never stop making noise!

In the summer, penguins have limited time to breed, so they do not stop their activities. Even when it’s dark, they continue calling their partners as they return from foraging. This means that there is a constant loud concert of hundreds of penguins when you are trying to sleep.

I think those days were the hardest, smelliest days of fieldwork that I have had in my whole career. Despite all the challenges, however, it was amazing to experience such an adventure. We were fortunate to access such a plentiful colony. Magellanic Penguins are protected species and not everyone is lucky to look inside their lives. At times we were so smelly and covered with dirt, that in a certain sense, we felt part of the colony.

What do you think about Magellanic Penguins, their lives, and more? Are they your favorite penguin? If not, what is? Would love to hear what you think, what you learned, and more!


Visit our other recent blogs to read more about penguins:



2. Scioscia, G., Rey, A. R., & Schiavini, A. (2016). Breeding biology of Magellanic Penguins (Spheniscus magellanicus) at the Beagle Channel: interannual variation and its relationship with foraging behaviour. Journal of Ornithology, 157(3), 773-785.


Do all penguins love the cold?

Galapagos penguin
by Nataly H. Aranzamendi

All species of penguins are restricted to southern latitudes and most of us think of them in cold climates and Antarctic snow. But there are two species that venture farther north, reaching the equator. They are sun-loving penguins: The Humboldt and Galapagos Penguins.

Some penguins love cold, some penguins love the heat

Penguins split their lives between two landscapes: in ocean waters when searching for their favorite fishes and squid, and on land when it’s time to breed or to change new feathers. The Galapagos and the Humboldt Penguins, like other penguin species, are top predators of marine food webs and key elements for the balance of southern marine food chains. Both species live in habitats that look quite harshly similar. The Humboldt Penguin likes to nest in guano mounds on rocky shores and cliffs, and similarly the Galapagos penguin likes rocky crevices and protected shelters. 

Although these penguins are sun-loving birds, they are still associated to relatively cold temperatures, as their distribution is mainly determined by the presence of the Humboldt Current, a current with cold waters that flow north from Antarctica all the way to the Galapagos. The Humboldt Current is one of the world’s most productive, filled with nutrients which are ideal for plankton and wildlife to thrive. 

Many threats to Humboldt and Galapagos Penguins

Both species of penguins have gone through dramatic population fluctuations. In the 18th century, Humboldt Penguins occurred by the “hundreds of thousands” before the guano exploitation started. Together with human exploitation and decrease of available habitat, these species have also been negatively impacted by water temperature fluctuations provoked by El Niño, an increase of invasive species, and new wildlife diseases to name a few threats. Here’s a summary of the most relevant facts for each species:

Facts about Humboldt Penguins

Humboldt Penguin

Humboldt penguin
Photo: Adam Kumiszcza

Humboldt Penguins (Spheniscus humboldti) used to be abundant in the 18th century. Historical records mention “millions of birds” along rocky beaches in the coasts of Peru and Chile. When the exploitation of guano began, penguins saw their nesting grounds being constantly disturbed and they quickly abandoned those areas. Moreover, their numbers decreased as a result of direct hunting of adults and egg harvesting. 

Their current numbers are calculated at around 30,000 individuals (accurate estimates unknown due to deficiencies in survey methodologies). Although population numbers seem stable and/or growing in some years, Humboldt Penguins are classified as Vulnerable by the International Union for the Conservation of Nature (IUCN). Sometimes when strong El Niño events hit, they can face years with up to ~60% mortality of individuals. The main reason for such dramatic declines is linked with their favorite prey: Anchovies and other small fishes swim deeper in cold waters or farther away from penguin’s foraging areas when El Niño’s warm waters invade the Humboldt Current. Unfortunately, it is very likely that El Niño events will become more frequent and less predictable in a warming world, endangering the probabilities of immediate recovery for Humboldt Penguins.

Industrial fisheries and the risk of entanglement on gill nets pose another threat for this species. Although Humboldt Penguins prefer to stay close to their nesting colonies during breeding, non-breeding individuals venture farther away during winter, as has been shown by recent tracking of individuals, increasing the likelihood of encounters with fisheries.  

Penguins and their eggs are also easy prey for invasive species. Rats, feral cats and dogs and even human activity have had an effect on nesting populations. Current management programs in the largest colonies of Humboldt penguins include the eradication of such species with preliminary positive results. However, this implies a gigantic amount of work and management programs now run mostly in protected areas and with limited budgets. 

Facts about Galapagos Penguins

Galapagos penguins

Galapagos penguins
Photo: Hjalmar Gislason

The Galapagos Penguin (Spheniscus mendiculus) can be found only around two islands in the Galapagos archipelago: Isabela and Fernandina islands. Like its closest neighbor the Humboldt Penguin, the populations of Galapagos Penguins have experienced dramatic numeric fluctuations (up to 80%) provoked by El Niño events, introduced species, and new diseases. 

The threat for this species, however, is potentially more dramatic than the one for the Humboldt Penguin, since their numbers do not exceed 5,000 individuals. Due to their restricted geographical location and limited numbers, the Galapagos Penguin’s current status by the IUCN is Endangered. 

Galapagos Penguins are also threatened by local fishing operations and the possible arrival of diseases such as bird malaria. Moreover, climate change may likely decrease the availability of its various fish prey which could possibly limit the chances of successful nests for this bird. 

How do we protect Humboldt Penguins and Galapagos Penguins for the future?

Species can persist if coordinated efforts by scientists, authorities, local fisherman and the general public start alleviating pressures coming from human sources. For example, the installation of artificial nests can potentially increase available habitat for both species and increase their chances of yearly nest success. 

Similarly, restricting access to breeding grounds for tourists, local fishermen and public in general has been a strategy that has proved successful for many other marine birds for which their nesting colonies have been re-populated. This strategy could also potentially work for these penguins.  

An urgent and forceful control of invasive species might have the strongest immediate impact on nesting birds and could boost population numbers and recruitment. 

Most importantly, public awareness constitutes a powerful tool for the preservation of any species. It’s crucial to understand the impact of our activities on the world (e.g. fishing, climate change) and the ways to mitigate our negative individual impacts. Hopefully, all these measures implemented could offer a more positive prospect for these sun-loving penguins and one day we might even see thousands of them again enjoying the sun on their rocky beaches. 

Have you ever seen Galapagos or Humboldt penguins in the wild? Tell us about it in the comments below.

Read more about Adelie Penguins and Northern Rockhopper Penguins!


Hug t-shirt

Last sale before the holidays!

Now through Sunday. Shop now!

Penguin Hug

Send a Pen Pal to Your Favorite Person

It’s like getting a hug from a Penguin

Brighten Someone’s Day for FREE

Email your favorite people a positive message. It’s a penguin post called a Pen Pal. Send as many as you want for FREE.

Send Your First Pen Pal Right Now!

Brighten Someone’s Day for FREE

Email your favorite people a positive message. It’s a penguin post called a Pen Pal. Send as many as you want for FREE.

Send Your First Pen Pal Right Now!