The Galapagos Islands are home to some uniquely adapted animal species, but being a tropical archipelago, you probably don’t associate the Galapagos with cold-loving penguins. But surprisingly the Galapagos does have its very own penguin species, and true to Galapagos form, it’s unique.
A surprising home for penguins
Although the Humboldt and Cromwell ocean currents bring cool penguin-friendly waters to the Galapagos, and supply nutrients that allow the archipelago to support large stocks of fish on which the penguins can feed, the Galapagos Islands bake under a fiercely hot equatorial sun, and the life giving ocean currents can also periodically disappear.
To cope with the heat, and periods of greatly reduced food supply, the Galapagos penguin (Spheniscus mendiculus), the world’s only equatorial penguin species, has had to evolve a suit of unique physical and behavioural adaptations.
Living in the sun
To prevent overheating in the sun, the Galapagos penguin has less body fat and fewer feathers than cold-weather penguins, and has areas of bare skin that they use to radiate heat away from their bodies. The Galapagos penguin is also the second smallest penguin species, as a small body size means a larger surface area in relation to their volume, with which they can lose body heat more efficiently than larger penguins. Penguins can’t sweat to lose heat, so the Galapagos penguins pant when they’re hot, like dogs.
Galapagos penguins, sensibly, tend to hunt in the cool water during the day and come onto land at night. And when on land during the day, the penguins adopt a characteristic pose, holding their wings out at their sides to lose heat to the cooling sea breeze, and they hunch over their feet to keep them in their shadow, to stop the exposed skin from absorbing the sun’s rays.
A small body size helps the Galapagos penguin cope with periods of little or no food, as a smaller body requires fewer calories, but Galapagos penguin society also shows adaptations to help them cope with periodic scarcity.
Whereas most penguin species hunt in groups, Galapagos penguins usually hunt by themselves or in pairs, to ensure they search far and wide for food, and whilst most penguin species nest in colonies, the Galapagos penguin often makes solitary nests in order to take advantage of limited areas of shade. When it comes to breeding, most penguins usually have seasonal breeding cycles, but the Galapagos penguin instead breeds opportunistically, whenever conditions are favourable.
The Galapagos penguin is unique, but unfortunately is also remarkable as it’s the rarest penguin species in the world. As they’re only found at the Galapagos archipelago, the penguins are vulnerable to environmental changes at the Galapagos, both natural, such as changes in ocean currents, and also man-made, particularly the introduction of cats, dogs and rats, which feed on penguin eggs and chicks.
by Daniel Swindlehurst
How you can help the Galapagos penguins
We are currently fundraising for a vital Penguin Monitoring Project. With your support, we will be able to fund research trips to the penguin colonies where scientists can work to prevent the ongoing threats to penguins, like rats and avian malaria. This year the penguins also face the threat of the upcoming El Nino, meaning that this monitoring project is more critical than ever. We want to everything we can to protect the world’s rarest penguin, if you can help, please make a donation here.