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Yellow-eyed Penguins – one of the rarest penguins in the world

endangered species, what is the rarest penguins, how many types of penguins are there, where do penguins lives, what do penguins eat, what color eyes do penguins have

The Yellow-eyed Penguin – one of the rarest penguins in the world

by Georgia Podmore

The Yellow-eyed Penguin is one of the rarest penguin species in the world. It is found north of the Antarctic Ocean, along the coast of Southern New Zealand (Ellenberg, Mattern and Seddon, 2009). As the name suggests, the penguin is easily identifiable by the yellow colour around its eyes, along with a brightly coloured yellowish line that runs from its eyes round the back of the head.

Yellow-eyed Penguin characteristics

Like other penguins, the Yellow-eyed Penguin is carnivorous and preys on marine animals, such as crustaceans, cephalopods and fish. They are one of the larger species and can grow to approximately 75cm in height (Ellenberg et al., 2007). The penguins will breed once a year with their mate, who remain faithful to each other. The female will lay two eggs and both parents will help with incubating the eggs until they hatch. Once hatched, the chicks will stay with their parents until approximately twelve months old. The nesting sites for Yellow-eyed Penguins can be found in the forestry and shrubs that run alongside the southeast coast of New Zealand (Doc.govt.nz, 2019). Historically, the nesting sites have been undisturbed, however in recent years the penguins have had to face land predators. This has resulted in the species becoming an endangered animal with a wild population of less than 4,000 individuals (Yellow-eyed Penguin Trust, 2017).

Threats to Yellow-eyed Penguin populations

Predators

Yellow-eyed Penguins must deal with predators near their breeding grounds that are now beginning to hunt on their eggs. These predators include feral cats, stoats, ferrets and dogs (Ellenberg et al., 2007). On land, these predators are generally not a cause for concern for adult penguins. However, due to predation on their eggs, Yellow-eyed Penguin breeding success has been declining in recent years. Predators in the ocean include sharks and fur seals. The penguins have no defense against such large predators in the water, relying strictly on swimming speed and manoeuvrability, or escaping out of the water to dry land. Like all penguins, their colouration also helps disguise them from predators, as sharks and seals may find it difficult to see the penguins from below due to their white chest, or from above due to their black backs.

Human Interference

Humans have already disrupted Yellow-eyed Penguin populations by introducing some of the penguin predators into their areas. Another way in which humans have affected the number of penguins is through disturbance from the tourism trade (Ellenberg, Mattern and Seddon, 2009). Being a spectacular penguin to look at — along with its endangered status — brings in large numbers of people who want to see these animals in the wild before they’re gone. Research has shown that large numbers of tourists can be associated with reduced breeding success, along with decreased fledgling weight, which can then affect their survival rate in the first year (Mattern et al., 2007). These factors may be influenced due to stress on the adult penguins which may affect normal behaviour. 

Disease

As the climate is warming, disease is becoming a bigger issue for Yellow-eyed Penguins. Avian malaria was responsible for 29 deaths in 2018/19 (Yellow-eyed Penguin Trust, 2017), a large and impactful number for such a small population. With increased temperatures leading to increases in mosquito breeding, the threat for disease to penguins is expected to increase. Avian diphtheria is also affecting the species, which is commonly found in young chicks. Bacterial plaque forms in the mouth of the chick and is subsequently inhaled, which eventually causes aspiration pneumonia, a potentially fatal illness.

Stress can also cause penguins to become more susceptible to disease, which for the Yellow-eyed Penguin may be coming from increased threats and tourism. 

Deforestation

Habitat loss has become one of the main reasons the number of Yellow-eyed Penguins are decreasing (Mattern et al., 2007). In New Zealand, forests are being cleared to make way for field areas for grazing animals or homes. This is then resulting in increased pressure for the penguins as they attempt to find nesting areas. 

How can we help these extremely endangered Yellow-eyed Penguins?

Help for the Yellow-eyed Penguin started in the 1980s when the population was extremely low (Sue, 2019). Conservation organisations are focusing on protecting the forest and shrub land for the penguins to ensure they have the space to breed and build their nests, thousands of plants have also been planted around the areas for protection. Although this all sounds beneficial, help is still needed to protect more areas or to re-establish areas that have already been cleared.

In New Zealand, there is the Otapahi Reserve which is a protected area for the penguins, to ensure that they can live and breed without being disturbed by humans and predators. Dunedin Wildlife Hospital has also begun catching penguins with injuries and rehabilitating them. Veterinarian Lisa Argilla states, “We do what we have to do to save the species, as we cannot fix climate change and habitat destruction” (Biologicaldiversity.org, 2014)

There are a large amount of conservation groups and rehabilitation centres now working to support the Yellow-eyed Penguins and to help increase the population. Every effort is being made to ensure that the population is protected, and with support from the public we can all strive to make the maximum impact and hopefully save the Yellow-eyed Penguin from extinction.

Did you know about Yellow-eyed Penguins? And how rare they are? Did you like what you learned by reading this blog? Leave a comment below. And please help us to continue to provide you with penguin news articles by donating to Penguins International.

Read more about penguins in some of other blogs:

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Reference List

Biologicaldiversity.org. (2014). Yellow-eyed penguin. [online] Available at: https://www.biologicaldiversity.org/species/birds/penguins/yellow-eyed_penguin.html [Accessed 31 Aug. 2019].

Center for Biological Diversity (2019). Yellow-eyed Penguin. [image] Available at: https://www.biologicaldiversity.org/species/birds/penguins/yellow-eyed_penguin.html [Accessed 31 Aug. 2019].

Doc.govt.nz. (2019). Yellow-eyed penguin/hoiho. [online] Available at: https://www.doc.govt.nz/nature/native-animals/birds/birds-a-z/penguins/yellow-eyed-penguin-hoiho/ [Accessed 31 Aug. 2019].

Ellenberg, U., Mattern, T. and Seddon, P. (2009). Habituation potential of yellow-eyed penguins depends on sex, character and previous experience with humans. Animal Behaviour, 77(2), pp.289-296.

Ellenberg, U., Setiawan, A., Cree, A., Houston, D. and Seddon, P. (2007). Elevated hormonal stress response and reduced reproductive output in Yellow-eyed penguins exposed to unregulated tourism. General and Comparative Endocrinology, 152(1), pp.54-63.

Mattern, T., Ellenberg, U., Houston, D. and Davis, L. (2007). Consistent foraging routes and benthic foraging behaviour in yellow-eyed penguins. Marine Ecology Progress Series, 343, pp.295-306.

Sue, M. (2019). Penguins: Yellow-eyed Penguins – Megadyptes antipodes. [online] Penguins.cl. Available at: http://www.penguins.cl/yellow-penguins.htm [Accessed 31 Aug. 2019].

Yellow-eyed Penguin Trust. (2017). Distribution and habitat. [online] Available at: https://www.yellow-eyedpenguin.org.nz/penguins/distribution-and-habitat/ [Accessed 31 Aug. 2019].

Penguins are overheating! Yep, you read that right!

Penguin skin showing feather density

Penguins are overheating! Yep, you read that right!

By Beth Storey-Jones

What do you imagine when you think of penguins? 

  • Highly adapted?
  • Caring parents? 
  • Amazing swimmers? 
  • Looking fly in their tuxedos? (no pun intended)

Well you would be 100% correct on all accounts. You might also worry about how they may struggle to keep warm? In fact, this isn’t their primary issue. They’re actually more at risk of overheating! Yes, I did say overheating. This is a real problem and is becoming detrimental to penguin populations. Let me explain!

Brief penguin anatomy and physiology lesson

First, let’s take a brief look at a penguin’s anatomy and physiology. They are aquatic, built for life at sea. To allow them to thrive in the water, warm-blooded animals need to be well insulated. Whales have blubber, seals have thick fur pelts, but birds have neither. Evolutionarily speaking, birds avoided adaptations that would hinder flight. So, penguins have had to use pre-existing characteristics and tweak them to survive in their niche, this being their feathers.  As a result, these feathers are short, ridged and interlock [1] to form an air trap (figure 1). Which is equivalent to a dry suit. Any heat obtained by the bird is kept in between the base layer of the feathers and the top layer of the skin, and works well as an insulator when in the water. The trouble comes when this same heat is not released, as when they return to land.

Fig. 1 Penguin skin showing feather density [1]

Penguin Distribution – Where do they live?

Fig. 2 Penguin Range Map [2]

Contrary to popular belief, most penguin species live in temperate and even tropical zones, not Antarctica (Fig. 2). Consider the Little Blue Penguin, who breeds up and down the coasts of Australia and New Zealand [2]. They often only come ashore once the sun begins to set. A more popular species, the Galapagos Penguin, avoids direct sunlight by creating nesting areas in shaded lava rock cracks. Water temperature can also be as high as 30oC (86.0°F) around the equator [3] and for a bird that has to maintain an internal body temperate of 39oC (102.2°F) this can be challenging. With their feathery armour only just able to regulate this temperature, prevention methods aren’t always the best medicine.

So, how do penguins combat hyperthermia? To answer this question in short, thermoregulation adaptations. It’s really interesting, so I’ll elaborate! You may have noticed that quite a few bird species have naked legs or webbed feet, or both. These areas of the body house complex blood vessels which can constrict to control the amount of heat loss when cold or expand to lose heat when the animal is too hot, comparable to a radiator [3]. Penguins such as the Humboldt Penguin also have featherless faces. Behaviourally, penguins pant. Which evaporates the body’s moisture while using up body heat to do so. Much like your dog, when he’s retrieved his favourite tennis ball for the 100th time. Penguins will also hold their flippers out to the side to allow breezes to cool them down even further.

Chicks at risk

Penguin chicks are also at risk of overheating. Their soft down is even more efficient at heat retention. While unable to thermoregulate, chicks are sheltered from the sun by their parents. Unlike the adults, their flippers are also covered in insulating down. So, the babies have to rely on their disproportionately large (and cute) feet (Fig. 3) to act as a personal radiator [3]. On exceptionally hot days, juveniles have been observed essentially laying like a starfish on the ground to expose their feet. Some species will even stand in water. 

Fig. 3 The extra-large feet of a penguin chick [3]

Challenges ahead…

So far, it has been explained that heat regulation is a bit of a challenge for the penguin. That is without even taking into consideration our global warming crisis. I know, I know, everyone is talking about it. But it is a vital element to consider in the lives of our beloved penguin friends. The finely tuned adaptations we have talked about did not happen overnight. It was through the millenia-long trial and error process of evolution and will still be ongoing today. These adaptation changes aren’t necessarily a problem, but it’s the small window of opportunity that these animals (as well as other species) have to do it in when temperatures rise quicker than evolution. Sadly, this is where the detrimental part comes in. Sea temperatures are increasing. Penguin chicks are struggling to survive due to poor food quality and quantity from these temperature increases[4]. The warmer climes seen in Antarctica recently are causing unprecedented rainfall and the melting of potential snowfall. This can be damaging to eggs that must be kept dry and warm. And the chicks may also become muddy and wet and can succumb to hypothermia because their down feathers are not waterproof[4].

Let’s bring it all together. Penguins live in water. They inhabit not only the harsh, dry and cold parts of the world, but surprisingly also some of the hottest. They have finely-tuned mechanisms to allow them to do so. Such as radiators for feet and dense plumage for when they need to stay warm. But these adaptations are so specialised to their surroundings, that any changes can be fatal. With sea temperatures rising, food availability and competition is high, as well as the risks of chicks being exposed to hyper or hypothermia. This brings a bit of a chilly end to an extremely cool topic!

Thinking of penguins in general, do you think they would overheat? Did you like what you learned by reading this blog? Leave a comment below. And please help us to continue to provide you with penguin news articles by donating to Penguins International.

Read more about penguins in some of other blogs:

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Reference List

  1. DeNapoli, D. 2010. The Great Penguin Rescue. New York. Free Press. 
  2. Muller-Schwarze, D. 1984. The Behaviour of Penguins – Adapted to Ice and Tropics. New York. State University of New York Press
  3. Kaiser, G. 2007. The Inner Bird: Anatomy and Evolution. Vancouver. University of British Columbia. 
  4. Sidder, A. 2016. Antarctica Could Lose Most of Its Penguins to Climate Change. [online]. National Geographic. Available from: https://www.nationalgeographic.com/news/2016/06/adelie-penguins-antarctica-climate-change-population-decline-refugia/ [Accessed 24 October 2019].

Figures

  1. National History Museum. 2018. Ever wondered how Emperor Penguins survive temperatures of -60 degrees centigrade? Their feathers are densely packed as these photos show but as researcher Cassondra L. Williams and colleagues discovered there is more to the story than meets the eye. [online]. Twitter. Available from: https://twitter.com/nhm_oology/status/1022076201828012032 [Accessed 24 October 2019].
  2. Kikkawa, E., Tsuda, T., Sumiyama, D., Naruse, T., Fukuda, M., Kurita, M., Wilson, R., LeMaho, Y., Miller, G., Tsuda, M., Murata, K., Kulski, J., & Inoko, H. 2009. Trans-species polymorphism of the Mhc class II DRB-like gene in banded penguins (genus Spheniscus). Immunogenetics. 61, 341-352.
  3. Tennessee Aquarium. 2017. Call It “Sasquawk”: Big Feet a Distinct Feature of the Aquarium’s Newest Penguin Chick. [online]. Tennessee Aquarium. Available from: https://www.tnaqua.org/newsroom/entry/call-it-sasquawk-big-feet-a-distinct-feature-of-the-aquariums-newest-pengui [Accessed 24 October 2019].

Have Penguins Ever Been Able To Fly?

Humboldt Penguin showing off its flippers and swimming ability.
(© Martin Franklin/ZSL)
Humboldt Penguin showing off its flippers and swimming ability.

Have Penguins Ever Been Able To Fly?

by Martin Franklin

Swimming is normal for me. I’m relaxed. I’m comfortable, and I know my surroundings. It’s my home.” (Michael Phelps, most decorated Olympian of all time).

Swimming is a confusing sport. Sometimes you do it for fun, but then other times you do it to not die. And when I’m swimming, sometimes I’m not sure which one it is. You have to go by the outfit. Pants – oh oh! Bathing suit – ok! Naked – we’ll see!” (Demetri Martin, comedian).

Penguin conservation is imperative!

(© Martin Franklin/ZSL)
Humboldt Penguins with a view of their flippers in the water.

In the course of my work as a zookeeper at ZSL London Zoo (a charity which supports animal conservation projects all over the world), I frequently get asked some pretty odd (often brilliant) questions. Recently two 6- or 7-year-olds asked me, “Have penguins ever been able to fly?” (A great question, I thought). Although we ended up talking about traits these children had inherited from their grandparents, I ultimately utterly failed to explain in simple enough terms to them how evolution works – entirely mea culpa. (Incidentally, for thoroughly clear and persuasive introductions to the facts and mechanisms of evolution, I’d highly recommend reading both Coyne1 and Dawkins2).

This incident did, however, prompt me to write this piece. Of course, penguins, as we understand and envisage them, have never been able to fly. But their ancestors, from whom they evolved, unquestionably could. The real question is to ask what pressures or opportunities caused that change.

Why do penguins swim instead of fly?

First, however, a quick look at flightlessness in birds generally. Although flying has proved advantageous to most bird species (and has thus been retained), a wide range (in terms of size, geographical spread and ecology) have evolved to discard the power of flight once possessed by their ancestors. These include:

  • “Ratites” (i.e. ostriches, rheas, emus, cassowaries and kiwis, plus the now extinct moas and elephant birds), which lack a keel (ridge) on their sterna (breastbones) onto which to attach flight muscles. 
  • Numerous waterfowl (Anseriformes) (e.g. Aukland Teals and Campbell Teals).
  • Two species of grebe (Podicipediformes) (i.e. Junin Grebes and Titicaca Grebes).
  • One of the pelican/cormorant group (Pelecaniformes) (i.e. flightless cormorants). 
  • One of the parrot group (Psittaciformes) (i.e. Kakapos). 
  • Numerous rails (Gruiformes) (e.g. Calayan Rails and Pink-legged Rails).
  • A variety of now extinct birds, including from the: pigeon and doves (Columbiformes) (e.g. Dodos); gamebirds (Galliformes); hoopoes (Coraciiformes); birds of prey (Falconiformes); owls (Strigiformes); nightjars (Caprimulgiformes); perching birds (Passeriformes); and auks (Charadriiformes).

Many of these flightless species come/came from remote, predator-free, food-abundant islands, which helps explain why they lost the ability to fly. It is “expensive” (in terms of energy required and lost other opportunities) for birds to maintain the necessary physical attributes needed for flight (e.g. large, calcium-rich, keeled breastbones and large chest muscles). Therefore, if it’s no longer necessary to fly to avoid predation or hunt, natural selection frequently results in less investment in such “expensive” materials/attributes.3

Flightlessness exists in many birds besides penguins

Flightlessness has also evolved independently in:

  • large-bodied, herbivorous birds (e.g. ostriches, emus, cassowaries, moas and elephant birds), as a diet of high-volume low-quality vegetation favours developing a large body, which in turn increases the challenges of maintaining the apparatus needed for flight; 
  • several foot-propelled diving birds (e.g. flightless cormorants), as these evolved to have powerful, paddle-like legs and feet (so their wings and chest-muscles became increasing less important for locomotion, and accordingly regressed); and
  • penguins (i.e. wing-propelled divers, that in water use their feet as a rudder, rather than for propulsion). These are by far the largest bird family whose entire members are flightless.4

The transition from flying birds to wing-propelled divers was a gradual process which started around 65 million years ago for penguins, and would have involved an intermediate stage whereby its ancestors could use their wings for both flying in the air and diving/swimming underwater (much as Razorbills, for example, do today). These ancestors were probably seabirds similar to modern diving petrels.

Strategies for a bird to choose swimming vs. flying

One of two strategies can be adopted once such a bird reaches a critical size of around 1kg (above which the size of wing needed for flying becomes too large for efficient swimming). Either: 

(1) the wings can be kept solely for flying, and the feet/legs can be used for underwater propulsion (as observed in most modern ducks and cormorants); or 

(2) aerial flight can be abandoned in return for superior underwater swimming (as happened with penguins).4,5

Gradually, therefore, as this ancestor fared better swimming underwater than flying above it:

  • No longer constrained by the necessity of flying as well as swimming, it was able to increase its weight. (One now-extinct penguin species, Anthropornis nordenskjoeldi, weighed around 135kg, and the modern Emperor and King Penguins are also relatively large animals). 
  • Slim wing bones became increasingly shorter and heavier, eventually resulting in the flat, broad (and less flexible) flippers sported by modern penguins.
  • Other related adaptations developed, including, for example, a hydrodynamic body shape and denser bones (unlike flying birds’ air-filled bones), meaning penguins are not overly buoyant. 

As a result, by 55 million years ago, penguins were completely flightless but thoroughly adapted to life in water.4,5

(© Martin Franklin/ZSL)
Streamlined bodies and rigid, flat flippers allowing strong swimming ability in penguins.

The adaptations that penguins have developed over thousands of years never ceases to be fascinating. Tell us your thoughts in the comment sections below. And please consider assisting with our conservation projects and helping us to continue to provide you this information by donating to Penguins International.

Read more about penguins in some of other blogs:

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References

1 Coyne, J. A. (2009). Why Evolution is True. Oxford University Press: Oxford.

2 Dawkins, R. (2009). The Greatest Show on Earth. Transworld Publishers: London.

3 McNab, B. K. (1994). Energy Conservation and the Evolution of Flightlessness in Birds. The American Naturalist. Vol. 144, no.4, 628-642.

4 Gill, F. B. and Prum, R. O. (2019). Ornithology. (4th edition). W. H. Freeman and Company: New York.

5 Lynch, W. (2007). Penguins of the World. A&C Black Publishers Limited: London.

Black and White, the Perfect Combination

Black and White, the Perfect Combination

Black and White, the Perfect Combination

By Megan Spofford

Dressed to the nines – penguin countershading

Penguins are often referred to as “wearing tuxedos”; an anthropomorphism that describes how most penguins have black feathers on their back with white on their belly. 

The tuxedo look of the penguin is known as countershading in the zoological field. Countershading describes how an animal is darker on the part of their body that faces the sun, and is lighter on the part that faces away from it (an example of this can be seen in the image above). It is important to remember that countershading only describes the coloration pattern of an animal, and not to use the term to define what it does for the animal.

Countershading provides penguin camouflage

The evolutionary purpose of countershading is highly debated, but it is most widely believed to function as a type of crypsis when a penguin is in the water. Crypsis is defined as a type of camouflage that protects an animal from predation. There are arguments for which category of crypsis it may fall under: either self-shadow concealment, or background matching. Self-shadow concealment essentially makes the penguin appear as a flat image, and potentially harder to distinguish from other things typically found in the environment, like rocks or ice. Background matching is where the penguin gets lost in its surroundings, because they look identical.

Penguin coloration under the water

It might stretch your imagination to think of a penguin being camouflaged in open water, however, marine habitats are the best at providing optimal lighting for a countershaded animal to blend in. When an animal is in the water, the light source is always directly overhead, making lighter colored objects closer to the surface harder to distinguish. When looking downwards, the ocean continually darkens, so dark objects would be obscured in this area. Because many natural penguin predators are strictly marine animals, it would make sense that they evolved feather colors that would make it harder for those predators to see them no matter where they happen to be located in the water. It is also beneficial for the penguin to be countershaded so that they themselves can prey upon fish and crustaceans!

 

Fossil evidence for the countershading hypothesis

The idea of countershading for camouflage has intrigued zoologists, artists, and militarists (who utilized the concept for weapons and bomber planes) for years. There are some proponents, however that believe the color of penguin feathers may be attributed to other factors, and the evidence for this is based heavily on the findings of a fossil from an extinct penguin in Peru.

Scientists were able to determine the color of feathers of the giant, extinct penguin despite degradation. They did this by examining melanosomes in the feather under a microscope, and it showed that they were a reddish color, instead of black.

Melanosomes are the organelles which create, store, and move melanin pigments in animal tissue. Melanin can come in one of two forms: eumelanin which has an oblong shape and accounts for darker pigmentation, and pheomelanin which is shorter and rounder (like an oval) and accounts for lighter pigmentation. In a comparison of feather color based on melanin, the fossil showed that it was colored by pheomelanin, while existing penguins are colored by eumelanin. 

What does melanin do, and what could that have to do with the color pattern of extant penguins?

There are a few different reasons eumelanin might have been triggered to be produced. In order to determine why this occurred in modern day penguins, we have to take a look at the environmental conditions that foster its development.

One that most of us are familiar with is its protective properties from harmful UV radiation. When skin, or feather tissue, is exposed to high levels of UV radiation, eumelanin is produced to block those rays, and thus becomes darker. For penguins that spend time at the equator where UV exposure occurs the most, they would need this melanin protection to keep from developing cancers. Obviously, the ventral (belly) side of a penguin is not exposed to UV radiation while swimming, which is why it would be lighter than the dorsal (back) side that is exposed.

Eumelanin has a molecular structure that is resistant to injury and breakage. Having eumalenain in the majority of your feathers would be beneficial for an animal that moves around on jagged ice formations, or has a high amount of drag load placed on their feathers while swimming speedily, like a penguin.

Further benefits of darker melanin are that it limits blinding glare (when light reflects off of a surface and affects vision), and it helps an animal camouflage into its surroundings in certain types of light (as discussed above!)

So, was eumelanin in feathers adapted mainly for camouflage purposes, or did it become a staple of modern day penguin genetic make-up for one of the other reasons, and it just so happens to also aid in crypsis? Researchers continue to test hypotheses to solve the mystery about the function of the countershaded penguin, so maybe one day soon we will have a definitive answer!

A blend of tuxedo and camo. Penguins are amazing animals. Like this story? Have a story of your own? Leave a comment below. And please help us to continue to provide you with penguin news articles by donating to Penguins International.

Read more about penguins in some of other blogs:

Like our penguin blogs? Sign up for our newsletter to get them right in your inbox!

References

Britannica, The Editors of Encyclopaedia. “Melanin.” Encyclopædia Britannica, Encyclopædia Britannica, Inc., https://www.britannica.com/science/melanin.

Clarke, Julia A., et al. “Fossil Evidence for Evolution of the Shape and Color of Penguin Feathers.” Science, American Association for the Advancement of Science, 12 Nov. 2010, https://science.sciencemag.org/content/330/6006/954.full.

Rowland, Hannah M. “From Abbott Thayer to the Present Day: What Have We Learned about the Function of Countershading?” Philosophical Transactions of the Royal Society of London. Series B, Biological Sciences, The Royal Society, 27 Feb. 2009, https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2674085/.

Stevens, Martin. “Animal Camouflage.” Google Books, Cambridge University Press, 7 July 2011, https://books.google.com/books?id=10TCvK-9v70C&pg=PA9&lpg=PA9&dq=ssc+camouflage&source=bl&ots=Kwy7skUjOm&sig=ACfU3U0X7ZZMAjFslKA_aAT05Z1-S3IgGA&hl=en&ppis=_c&sa=X&ved=2ahUKEwjzteO38K7lAhVOnJ4KHYYNCeMQ6AEwD3oECAkQAQ#v=onepage&q=ssc camouflage&f=false.

Cold Feet: Why Don’t Penguin’s Feet Freeze?

Adelie Penguins at McMurdo

Cold Feet: Why Don’t Penguin’s Feet Freeze?

by Sian Liversage

We all know that penguins endure and survive freezing temperatures in the Antarctic, these can range as low as -70˚C in the centre to -20 ˚C around the coast. Their bodies stay warm due to their insulating layers of blubber which lies just beneath the skin. However, their webbed feet are continually in contact with snow and ice, and yet somehow they manage to stay free from frostbite. So, it begs the question: Why don’t their feet freeze?

Penguins have special adaptations to keep their feet from freezing

Like many other species around the world, penguins have adaptations to avoid losing too much heat and to preserve a central body temperature. Penguin feet make it problematic to maintain that perfect body temperature of 40°C since they are constantly exposed to the elements; their feet cannot be covered with blubber or feathers like their bodies are, and together they create a large surface area exposed to the cold. But they need their feet so they can walk around the icy surface without slipping, and also so they can steer themselves when swimming. 

A variety of penguins have developed behaviours that enable them to keep their feet warm. For example, Emperor Penguins hunch down so their bellies and feathers cover their legs, and they also rock back and forth onto their heels to lift their feet off the ice, therefore reducing contact time on the ground.

Penguins keep their feet from freezing not only behaviourally, but also through internal mechanisms

This is not the only way penguins avoid getting cold, however. They have evolved remarkable physical attributes too that make them perfectly adapted to their environment. There are two hidden mechanisms going on inside those legs and feet.

First, a penguin can control the rate of blood flow to the feet by varying the diameter of arterial vessels supplying the blood. During cold conditions, the flow of blood is reduced to hold onto heat. In winter, penguins will keep their feet a degree or two above freezing which reduces the chance of heat loss and avoids getting frostbite.

Chinstrap Penguins walking on the snow

And, of course, not all penguins live in places where their feet get cold

Not all penguin species live in freezing conditions though. Some species like Galapagos Penguins live in scorching sun and heat and thankfully their specialised heat exchange system also serves as a vital outlet for when their bodies become too warm. Blood vessels in the penguin’s feet expand, doing the opposite of what they do when they are cold. This allows an increase in blood flow, which in turn enables heat loss from the body. You may see penguins lying on the ground with their feet in the air and their flippers out to the sides to speed this process up and get rid of excess body heat.

Magellanic Penguins in the desert in Argentina

Humans can also do what penguins do with their feet (to some extent)

Penguin feet closeup
Close up of the bottom of a penguin’s feet

Amazingly, humans can also restrict blood flow to their extremities too. Our hands and feet will go white when they are freezing due to less blood circulating to them; blood is being redirected and prioritised to go to the core of the body where the vital organs will be kept warm. On the other hand, when we are warm our hands and feet will turn pink which is our body trying to cool us down. Controlling blood flow is very sophisticated and involves the hypothalamus, the nervous system and endocrine systems all working together to function properly.

Secondly, penguin legs work like a heat exchange system; blood vessels to and from the feet are narrow and woven closely together, which cools the blood from the body on the way to the feet and vice versa when the blood returns to the body. Therefore, their feet receive cool blood instead of warm blood, as this means less heat is lost while the body continues to maintain that toasty 40°C. 

These adaptations show just how truly extraordinary penguins are; generations have survived the worst conditions nature could throw at them. These cold-adapted species live a challenging life, walking 100s of kilometres to feeding grounds, surviving snowstorms, and standing for weeks on ice while incubating an egg, and at the same time maintaining a warm body core temperature. Despite all these potential setbacks, their incredible feet and overall mechanisms to survive are still yet to be hindered by Mother Nature.

Penguins are amazing birds that have adapted ways to live in extreme environments. Have you ever seen some of these penguins in the wild? Tell us about it in the comments below. And please assist with our conservation projects and help us continue to provide you this information by donating to Penguins International.

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References:

  1. Encyclopedia Britannica Blog. 2011. Penguin Feet: Avoiding Frostbite in the Antarctic. Webpage: http://blogs.britannica.com/2011/01/penguin-feet-avoiding-frostbite-in-the-antarctic/
  2. How Stuff Works. 2019. Why Penguin Feet Don’t Freeze. Webpage: https://animals.howstuffworks.com/mammals/why-penguin-feet-dont-freeze.htm
  3. New Scientist. 2006. Why don’t penguins’ feet freeze? And 114 other questions. P. 47-77

Penguin Record Breakers

Emperor Penguin with Mount Erebus

Penguin Record Breakers

by Martin Franklin

At 100-130cm long and 22-40kg in weight, the Emperor Penguin is by far the largest of all the penguins. (This is, incidentally, only a little smaller than champion gymnast Simone Biles, whose height is 142cm and weight 48kg). But do the Emperor Penguin’s height and weight advantages translate into record-breaking penguin performances?

(1) Greatest Diving Depth – Emperor Penguin vs. Human

Alexey Molchanov holds the current human world record for the deepest single-breath dive (with fins, and without use of weights or inflation devices). He managed 130m. (Without fins, William Trubridge holds the record, at 102m). This equates to the Emperor Penguin’s preferred “average” dive depth, but it can easily dive to 400m, and has even been recorded at a depth of 564m. With a pressure at such depths of up to 30 times that at the surface, and no other penguins able to descend so deep, the Emperor Penguin is unquestionably the champion deep sea diver.1,2

(2) Longest Time Spent Under Water for Emperor Penguins

The human record for this is currently held by Stephane Mifsud, who lasted 11m 35s. This, however, was stationary and in a shallow swimming pool, meaning his physical exertion was negligible, and he was unaffected by water pressure associated with water depth. Again, the Emperor Penguin beats this hands (or perhaps flippers) down: It prefers short dives of 3-6 minutes, but can stay under water for up to 22 minutes, which is longer than any other bird can manage.1

Southern Rockhopper Penguins diving into the water

(3) Fastest Swimming Speed of Emperor Penguins

The human world record holder in the 100m freestyle is Cesar Cielo, with a time of 46.91s, which equates to around 4.8mph (7.7kmph). The unofficial fastest recorded penguin to date (though others could be faster) is the Gentoo, at around 22mph (36kmph). That’s around 5 times faster than the fastest human.

Gentoo Penguins after a day of fishing

Penguins achieve these incredible speeds due to their unique anatomy, which includes:

  • A torpedo-like body shape (including legs placed far back on their bodies) which results in remarkably little drag (the legs only being used for steering when swimming);
  • Flattened and rigid wing bones, the arrangement of which (unlike in flying birds) create significant forward propulsion on both the up and down-stroke;
  • A silky outer layer of feathers; and
  • Heavy (non-pneumatic) bones, so the birds are not fighting buoyancy in the way flying birds would.

Penguins also have handy built-in “goggles”, meaning they can see well on both land and in water, as they possess:

  • Nictitating membranes (i.e. a transparent inner eyelids which can be drawn over the eyes);
  • Flat corneas (the transparent front part of the eyes), which reduce refraction (light changing course in different ways in different media); and
  • Strong focusing muscles (allowing them to change their lens shapes as required).1, 3

(4) Competitive Eating (and Remarkable Egg-Care)

Penguins can eat an astonishing quantity of food very quickly, and their consumption increases markedly at particular times, i.e.:

  • Immediately before they moult (during a moult, which typically lasts a few weeks, they are no longer water-proof or able to thermo-regulate effectively, and thus cannot go fishing at sea);
  • When they have chicks to feed (which are fed regurgitated food);
  • In the case of Emperor Penguins, immediately before they start their long (up to 125 mile/200km) “march” to form breeding colonies. This is followed by the males taking on egg-incubation duties (which last for 62-67 days without food and in temperatures as low as minus 60oC, unassisted by their female partners, and with only the body heat of other males with whom they huddle to help stay warm).

This feat of the Emperor Penguin breaks numerous records, including:

  • Being the only penguins to breed during the Antarctic winter;
  • This being the most intense cold experienced by any warm-blooded animal;
  • This being the longest continual incubation period of any bird (although kiwis and great albatrosses incubate for 71-84 days, they leave their nests to feed)2;
  • Males being able to regurgitate a protein-rich stomach secretion to feed their chicks for up to 10 days (if the females don’t get back to share chick-feeding duties in time);
  • Being the only birds (technically) never to touch land (as they generally form their breeding colonies on winter sea ice).1

Adélie Penguins have been reported as able to eat 25g of krill per minute (which equates to around 0.5% of their body weight per minute).3 This species has also been  reported as eating around 800g of food per bird per day (which equates to around 16% of their body weight).4 In terms of weight alone (not calorific content), this is broadly equivalent to an average American man eating two 240g “Big Mac” hamburgers per minute, or 59 “Big Macs” per day.

Two colleagues tell me anecdotally that they once witnessed a chick-raising pair of Humboldt Penguins at ZSL London Zoo rival even the Adélie Penguins mentioned above. In just a few minutes, I am told that these birds (a female named Heidi and a male named Lars, pictured) each ate approximately 80-100 sprats (weighing around 840g). Given these penguins’ normal weights of around 4½kg each, this equates to them each eating around 19% of their normal body weights in one brief sitting.

 

Of course, Heidi and Lars were behaving naturally and appropriately, given their own nutritional requirements and those of their chicks at that particular time. I only wish I could claim a similar excuse myself in respect of my own occasional over-indulgences.

Lars and Heidi – Humboldt Penguins at ZSL London Zoo with (seasonal dependent) impressive appetites

© Martin Franklin 2019

 

Martin Franklin is a bird keeper at ZSL London Zoo, and works extensively with Humboldt Penguins. Any views or opinions expressed in this article are the author’s own, and do not necessarily represent those of ZSL

 

Penguins are amazing animals with even more amazing adaptions that help them live in extreme places. Like this story? Have a story of your own? Leave a comment below. And please help us to continue to provide you with penguin news articles by donating to Penguins International.

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References

1 De Roy, T., Jones, M. and Cornthwaite, J. (2013). Penguins: Their World, Their Ways. Bloomsbury Publishing: London.

2 Lynch, W. (2007). Penguins of the World. A&C Black Publishers Limited: London.

3 Williams, T. D. (1995). The Penguins. Oxford University Press: New York.

4 Culik, B. M. (1993). Energetics of the Pygoscelid penguins. Habilitation thesis. University of Kiel.

Penguins in Captivity: Keeping them happy

Southern Rockhopper Penguin

Penguins in Captivity: Keeping them happy

By Sian Liversage

It seems that no matter what age you are, whether a child or an adult, one of the most popular and interesting animals to see when visiting a zoo or an animal attraction are the penguins. People have certainly anthropomorphised this species because of the way they look and behave; a good example of this is how they are often compared to a small human wearing a tuxedo. Their waddling gait, clumsy nature and charismatic personalities make them an ideal species to have in captivity, simply to bring the people in. But should they be kept in captivity in the first place?

There is definitely a balance to keeping penguins happy and healthy in captivity

We can’t hide the fact that there are some negative sides to life while living in the care of humans, especially if animals are mistreated or not appropriately housed. Penguins are no different when it comes to struggling in a captive situation.

In one facility, staff had to administer medication to their Humboldt penguins after they showed signs of stress attributed to the difference in local weather that was very different to their natural climate.

Stress can lower a penguin’s immune system, which could cause them to be more vulnerable to diseases, especially if they are kept in poor conditions. Enclosures that are small, with small pools, means that penguins cannot display their natural behaviours, which in turn will increase their stress levels. Another facility nearly ten years ago had several Humboldt Penguins die of infections from unknown causes. This could have been attributed to stress from living conditions or lack of staff knowledge, or any other number of reasons.

Despite the best intentions of an animal keeper, things don’t always go smoothly. For that reason, we promote AZA accreditation in the U.S. and BIAZA membership in the U.K. for facilities that meet strict guidelines for animal management and care. The standards held by facilities with this oversight will ensure the best care is given to all of their animals. 

Animal care and management goes beyond best practices, however. The penguins need to be kept engaged and in an environment that promotes enrichment.

Zoo enclosures have advanced dramatically in keep penguins happy and healthy

Zoo enclosure designs have come a long way since the bare concrete space that animals used to live in, now providing an engaging, healthy sanctuary for penguins. Zoos and aquariums also play a key role towards conserving endangered species too, of which there are a large proportion of penguins under this category. Likewise, many zoos and aquariums aim to promote conservation work, educate the general public, and support wildlife projects. All of these categories merge to create a standard of welfare, which means that penguins which are kept in captivity are given the utmost care. These standards are in place to allow the animals to develop in a healthy environment as similar to their natural habitat as possible.

New enclosure designs promote more natural behaviours in penguins

The Detroit Zoo recognised that their penguins needed something more in their enclosure, so they replaced a 6-foot deep pool with a 25-foot deep pool. The penguins ended up spending extra time in the water than previously, showing the zookeepers that this new change enhanced their lives that much more. The penguins spoke and their keepers listened.

Flagship species, like penguins, will draw crowds in, helping to raise their profile. This will in turn fund conservation efforts to help protect the species in the wild. So, keeping them in an enclosure that promotes their natural behaviour is vital not only for giving them a stress-free life, but also for educating the general public on their behaviours and the conservation work that is ongoing throughout the world.

Humboldt Penguin stands on the edge of its pool. Photo found at: https://www.penguins-world.com/penguins-in-captivity/

No matter what evidence is put forward though, animals in captivity whether it be focusing on penguins or not, will continue to be a controversial issue that is widely discussed. From the evidence shown in this blog, it seems that as long as penguins can behave naturally, they are able to live a long happy life in a human made environment without predators. The efforts that zoos and parks will go to nowadays to keeping their animals stress free is astounding, and I think it’s safe to say that people have learned from the past and will continue to learn the needs of their animals for the future. 

Pro/con, zoos are helping penguins feel like they are more in their natural habitats while in captivity, but they will always feel do better when free. Please help us continue to provide you this type of information by donating to Penguins International.

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References:

DW Made for Minds. 2017. Should penguins be an animal attraction? Webpage: https://www.dw.com/en/should-penguins-be-an-animal-attraction/a-38557239

Penguins World. 2017. Penguins in Captivity. Webpage: https://www.penguins-world.com/penguins-in-captivity/

In defence of zoos: how captivity helps conservation. 2016. Webpage: http://theconversation.com/in-defence-of-zoos-how-captivity-helps-conservation-56719

Why are we still lacking effective conservation measures for penguins?

Southern Rockhopper Penguin

Why are we still lacking effective conservation measures for penguins?

by Nataly H. Aranzamendi

Penguins are in trouble. Despite being loved by people and being the target of large amounts of research, many penguin species are currently classified in an endangered category. In order to protect these amazing birds, penguin conservation efforts need to be initiated, strengthened and supported.

Penguin conservation is imperative!

More than half of the 18 penguin species are considered to be in decline and their populations have not recovered since penguin conservation efforts began1. Even for those species that are showing positive signs of recovery, multiple threats still make their situation at jeopardy. 

To discuss and underline which are the most immediate conservation needs to protect penguins, a group of scientists working with penguins, the IUCN Penguin Specialist Group, held a workshop and has published their most relevant conclusions1. Following are some take home messages from this work. 

What are threats to penguins?

Using a pairwise ranking approach, the scientists ranked penguins according to the most pressing global threats existing at the moment for all species. This approach gave a ranking of those species that needed more conservation and research. 

Another ranking was done for those penguins that need the most urgent conservation measures and immediate political intervention. Either because they are species experiencing rapid population declines or species with extremely limited distribution ranges. Three species were at the top of the ranking: African Penguins, Galapagos Penguins and Yellow-eyed Penguins. 

An Endangered African Penguin

Decreasing penguin populations

African Penguin populations have decreased since the early 1900s to only 21,000 pairs left. Their decline has been most likely caused by a lack of food as a byproduct of changes in climate and overfishing. Petroleum pollution and predation have had a major toll on this species as well. The IUCN Penguin Specialist Group has suggested that a network of Marine Protected Areas could offer protection for the majority of these birds, although the protection may not help during all life stages. 

Galapagos Penguin populations have suffered extreme number fluctuations, in relation to El Nino events. This species can skip breeding when food is scarce. That, in combination with limiting cavities for breeding, and the presence of invasive predators, has vanished any hopes of quick recovery. For this penguin with a very limited geographical range, the management of fisheries is crucial, since it will guarantee food at tough times. At the moment, less that 1% of the marine reserve around Galapagos is closed to fishing. 

The Yellow-eyed Penguin has suffered steep declines and currently only 1,700 pairs are left. This species faces several threats: introduced predators, environmental change and interaction with humans and fisheries. Managing these threats in conjunction could offer better perspectives for their future. 

Endangered Galapagos Penguins
An Endangered Yellow-eyed Penguin

Marine Reserves are the most powerful tool for penguin conservation

From all the measures discussed by the group of specialists, Marine Reserves were ranked as the most valuable tools for conservation existing to date. The creation of such reserves will allow management of several threats simultaneously, including those threats created by direct interaction with humans (i.e. tourism).  

But why has penguin conservation not moved faster in the last decades? The group agreed that most of the limitations are in relation to the penguin’s biology and funding problems. 

Penguins are colonial long-lived species that can potentially move beyond a country’s boundaries. This means that to effectively study them, long-term funding to follow individuals throughout their lives and international collaboration at many levels are needed. Such factors constitute the most limiting issues at the moment. 

Lack of long-term funding does not allow long-term monitoring of most populations. Moreover, due to practical reasons, most penguins are monitored only when they breed, leaving gaps of information about what they do in the non-breeding season. 

The non-breeding season, as well as the juvenile stage, are key elements to monitor, since it is at those stages that increased mortality occurs, which eventually would have consequences for population trends. 

Effective protection of international waters is also an issue. At the moment, only 2% of the ocean is protected, while the goal established by international agreements is to reach 30% of ocean protection. A goal that seems unreachable right now. 

To successfully protect penguins requires collaboration and communication between stakeholders: groups of scientists, legislators, NGOs, fisheries and local population. Without such collaboration, any ambitious conservation goal for penguins will not be reached. 

Action to protect our treasured penguins is needed now, because penguins are running out of time. It has become everyone’s work to take action for the penguins and their future.

As you can see, there’s still a lot of work that must be done to protect and conserve penguins. Please assist with our own conservation projects and help us continue to provide you this information by donating to Penguins International.

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References

  1. Boersma, P. D., Borboroglu, P. G., Gownaris, N. J., Bost, C. A., Chiaradia, A., Ellis, S., … & Waller, L. J. (2019). Applying science to pressing conservation needs for penguins. Conservation Biology 10.1111/cobi.13378.

The Antarctic Treaty Helps Antarctic Penguins

Antarctic Treaty, antarctica, Antarctic penguins, penguins, when was the Antarctic Treaty signed, what did the Antarctic Treaty do, how many countries signed the Antarctic Treaty, Environmental Protocol protects penguins, Environmental Protocol of the treaty

The Antarctic Treaty Helps Antarctic Penguins

By Megan Spofford

What is the Antarctic Treaty?

The Antarctic Treaty is a document comprised of 14 articles outlining laws about how to govern Antarctica, and was originally signed into agreement in 1959 (but officially enacted in 1961) by 12 different countries. These countries agreed to manage the location only with peace, and as a place for scientific research where ideas were shared amongst each other. Some of the countries had already lay claim to certain regions in Antarctica before the Treaty was signed, and although those particular regions may still recognize those claims individually, as a whole, they are not controlled by any particular nation per the Treaty. The area of coverage this pertains to is anything below 60º S latitude.

Signing of the Antarctic Treaty on December 1st 1959
Source: Antarctic Treaty Image Bank
https://atsimagebank.omeka.net/items/show/9

Who participates in the Antarctic Treaty?

As of 2019, there are currently 54 recognized countries that participate in the governance of the Antarctic Treaty. These comprise of the original 12, and 42 more who were added throughout the years (a full list is in the image below). Not all of the participatory countries are actively involved in research on the continent, however. While 54 countries may not sound like many in the grand scheme of things, in reality it truly is a substantial number because all the countries that are part of the treaty (regardless of conducting research or not) represent at least ⅔ of the world’s population. The leaders from each of the signatory countries engage in yearly meetings to address matters that concern the Treaty.

"Antarctic Treaty". United States Department of State. April 22, 2019.
Signing of the Antarctic Treaty on December 1st 1959
Source: Antarctic Treaty Image Bank
https://atsimagebank.omeka.net/items/show/9
Map of Territorial Claims in Antarctica
Source: CIA World Factbook

The Protocol on Environmental Protection to the Antarctic Treaty

An especially important meeting occurred in 1991 in Madrid where Article 12 was addressed. This article explained that the limitations of the Treaty should be reassessed after 30 years (remember this Treaty was enacted in 1961!), and that if any of the participating entities were disgruntled with any part of it, the committee needed to address it. This is when the Environmental Protocol happened to be drafted. The Environmental Protocol set forth the recognition of Antarctica as a nature reserve, and protects the natural resources and native species of the area. This is the portion of the protocol that protects Antarctic penguins! It was officially enacted in 1998, and since then, revisions have been added to the protocol to better specify its purposes, or extend its reach.

How the Environmental Protocol protects penguins

The Environmental Protocol covers Antarctic flora and fauna (the fauna portion includes penguins). In particular, it gives native penguins and other animals the status of “specially protected species,” and explains that they cannot be removed, injured, killed, or disrupted by human activity (such as by motorized vehicles or pollution of the environment from waste). In some cases where any of these may have to occur for the purposes of scientific investigation, or to preserve the species, permits must be issued by members of the Antarctic Treaty, and researchers must be sure to limit the activity to affect as few individuals as possible. Other protections in this protocol outline that non-native species cannot be introduced to the island, and that the balanced ecosystem cannot be disrupted. Furthermore, population assessments must be conducted on native species regularly enough to evaluate whether they are continuing to thrive. If they are not, then the problems facing the population must be addressed.

Adelie Penguins on an iceberg

Some of the most recent additions to the Environmental Protocol that have beneficial consequences for native penguins include: guidelines for reducing plastic pollution in Antarctica and the Southern Ocean (held in Prague in 2019), a non-native species manual (created in Santiago in 2016), identifying important bird areas in Antarctica (at a gathering in Sofia in 2015), meeting of experts on climate change (conducted in Baltimore in 2009), and many more in between those years, or before.

Setting an example

Thankfully, the Antarctic Treaty provides key protections to the native penguins of Antarctica, which include Gentoo, Chinstrap, Macaroni, Adelie and Emperor. It also sets a precedence across the world for many things: international cooperation for peace, appreciation for the importance of science, and respect for native wildlife. If it can be done there, then hopefully our leaders can use the Antarctic Treaty as a model, and transpose those practices (sometime in the near future) to the rest of the world when dealing with similar issues.

The Antarctic Treaty and Environmental Protocol have done so much to protect penguins. We look forward to seeing what happens in the future. Please help us continue to provide you this type of information by donating to Penguins International.

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References

“Antarctic Treaty Meetings.” Antarctic and Southern Ocean Coalition, www.asoc.org/advocacy/antarctic-governance/antarctic-treaty-meetings.

“Antarctic Treaty.” U.S. Department of State Archive, U.S. Department of State, 2001-2009.state.gov/g/oes/ocns/9570.htm#protocol.

“The Antarctic Treaty.” US National Science Foundation (NSF), www.nsf.gov/geo/opp/antarct/anttrty.jsp.

“Conservation of Antarctic Fauna and Flora.” Fauna and Flora | Antarctic Treaty, Secretariat of the Antarctic Treaty, 2019, www.ats.aq/e/faflo.html.

https://www.ats.aq/e/protocol.html#

https://www.ats.aq/e/antarctictreaty.html

Penguin ticks are well-adapted hitchhikers

ixodus tick

Penguin ticks are well-adapted hitchhikers

by Nataly H. Aranzamendi

Considering that some penguins live on remote islands, it is remarkable that ticks have managed to arrive to all seabird colonies around the world. Let’s discover tick strategies for survival and colonization.

Penguins are not immune to the presence of parasites. Similar to other marine birds living in colonies, we find penguins constantly infected by ticks. Ticks from the genus Ixodes are the most widespread ubiquitous parasite in marine bird colonies. 

As any other live organism, penguins are susceptible to parasite attacks.

Ticks have limited mobility and the only way for them to travel long distances is transported with the aid of their hosts. Ticks can quickly reproduce and spread on land in bird colonies, thanks to optimal conditions of bird agglomerations: Their proximity and interactions between individuals. Understanding parasite distribution, speed of spread, and possible impacts for bird health is a central topic in disease ecology. 

Transmission of parasites at terrestrial locations therefore is expected, but something that has puzzled scientists for a very long time is how those parasites can be found even in the most remote places, indicating that parasites might be able to survive oceanic conditions. After all, when penguins finish breeding or molting, they go back to the ocean for weeks or even months. 

However, many species of penguins reproduce on isolated islands or scattered colonies with low connectivity between them, potentially limiting the ability of ticks to disperse and colonize new environments, or at least that is what scientists have always assumed.

Ticks can even survive on penguins while in the ocean

In a recent set of experiments1, scientists have tested if ticks had the ability to survive and resist oceanic and physiological conditions imposed by penguins when traveling from one place to another. 

Ticks from the genus Ixodes were collected from a colony of Little Penguins in Australia. The survival of these parasites was tested in several experiments. First, ticks were exposed to experimental regimes of varying depths. In the past, scientists used to believe that these arthropods were not able to resist water pressure conditions at deep dives. However, in the experiments all ticks were able to survive and passed the test of 60 m in depth, which are the distances that Little Penguins can reach.

Penguins swimming in the ocean. Ticks can survive on them for weeks!

When ticks are buried deep within a penguin’s feathers, they have enough adaptations to survive even the harshest conditions

Then ticks were exposed to several temperature regimes. Arthropods can be very sensitive to temperature, which might affect their basal metabolism and their ability to survive. However, in the experiments most ticks survived to temperatures within the ranges experienced in a penguin’s body at sea. Depending on the tick’s initial body condition, some arthropods stayed alive even after two weeks, which is longer than the majority of Little Penguin trips. 

Subsequently, ticks were tested in a regime of saline conditions and once again they passed the test. These parasites also prefer certain locations in the penguin’s body, commonly found in the inner ear, the head and the upper body of penguins.

Penguins submerge underwater to dive for food, restricting the availability of oxygen for ticks. The group of scientists found that ticks had the capacity to close their spiracles (i.e. the organ that allows respiration) for periods that lasted longer than any penguin’s diving time.  The fact that penguins expose only their heads to breath after every immersion guarantees oxygen supply for the parasites found there, and could explain why the arthropods prefer certain body parts. 

In summary, penguin ticks have proved to be well armed to survive the harshest of conditions in terms of temperature, depth, salinity and starvation. Such characteristics might help facilitate the arthropod’s survival and dispersal, and their capacity to arrive at even the most remote islands. This would explain why scientists keep finding the same kind of parasites everywhere, even when islands are separated by thousands of kilometers.

These findings have answered a long-unconfirmed suspicion. The next step will be to understand the consequences that the presence of parasites have on individual penguin colonies and the risks for penguins when favorable conditions lead to increases in infestations. In the meantime, it is very likely that we will keep finding ticks attached to most traveling penguins. 

Did you know ticks attached to penguins (vs humans or pets, as we might commonly think). And that they could stay attached to the birds for so long? They are determined! Please let us know what you think. We also greatly appreciate any support you can give us by donating to Penguins International so we can continue to provide you this type of information.

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  1. Moon, K. L., Aitkenhead, I. J., Fraser, C. I., & Chown, S. L. (2019). Can a Terrestrial Ectoparasite Disperse with Its Marine Host? Physiological and Biochemical Zoology, 92(2), 163-176, doi: 10.1086/701726
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