Life is serendipitous as we’re all victims of circumstance, born into our local environment. The Galápagos Penguins’ Pacific climate deal ensures that it can survive but only just.
This animal owes its existence to freak coincidences that began four million years ago when a crack in the ocean crust formed, about the same time as an ice-ageA period of reduction in Earth’s temperature of between about 4–7 degrees that resulted in the rapid expansion of ice sheets and glaciation of much of the Earth’s surface. More retreat [1]. Lava spilt forth and the famous Galápagos islands were formed, becoming a hotbed of evolution and inspiring Darwin’s theories. These avian castaways carved a living in the new world through hundreds-of-thousands of years of unintentional trial and error. By chance they still survive today.
Until people arrived in 1535, for the last 10,000 years there is little evidence of extinctions on the Galápagos[2] [3], and the islands’ ecosystemsHow ecosystems function An ecosystem is a community of lifeforms that interact in such an optimal way that how ecosystems function best, is when all components (including humans and other animals) can persist and live alongside each other for the longest time possible. Ecosystems are fuelled by the energy created by plants (primary producers) that convert the Sun's heat energy More are so new they are still evolving and dynamic.
Limited Pacific travel reduces survival risk
Galápagos Penguins live on the equator. They never see icebergs and being flightless, make a living confined to a small area. Venturing far away isn’t an option for this pint-sized penguin. Heading offshore risks predation by sharks. It also saps valuable energy, both high risk strategies for a small bird in a cold ocean.
To survive the penguins need an abundant and reliable food source within swimming-distance of their nest. In Australia, Little Penguins deliver food daily to newborn chicks. One parent remains at home to keep the fledgling warm. With a maximum swim-speed of about 3kph their effective shopping radius is only 10-20km.
Galápagos Penguins are even more range-constrained.
Galápagos Penguins need a fair climate for living
The key to Galápagos Penguin survival is an unlikely union with one of the Pacific’s biggest oceanographic features, the Pacific Equatorial Undercurrent. The scale of this ocean feature is vast. It’s 3,500 miles long and 250 miles wide. Yet it’s only provided marginal opportunity for the evolution of this unorthodox seabird.
The current strengthens and weakens over time. During El Niño, when the Pacific Ocean warms and trade-winds effectively reverse, the current almost stops and Galápagos Penguin populations crash through lack of food. You could say the relationship is a bit one-sided. It is a fascinating example of how sensitively wildlife existence is balanced.
To understand the significance of any species on Earth, you need to visualise the context of its existence. Human beings are no different. We live within extremely narrow environmental boundaries too. Relatively small changes in the distribution of energy on Earth leads to it becoming uninhabitable.
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The Pacific climate and ocean mixing
The Pacific Ocean is a steep-sided mixing bowl. Water flows in a conveyor-belt motion, with the surface in the opposite direction to the bottom.
A few hundred metres below it moves a mass of 30 million cubic metres a second steadily eastwards. The trade-winds that blow surface water east to west, are created by the rotation of the Earth. It’s these trade winds that reverse during El Niño years, effectively halting its flow.
When the undersea current collides with the Galápagos Islands’ western volcanic slopes, nutrientsEnergy and nutrients are the same thing. Plants capture energy from the Sun and store it in chemicals, via the process of photosynthesis. The excess greenery and waste that plants create, contain chemicals that animals can eat, in order to build their own bodies and reproduce. When a chemical is used this way, we call it a nutrient. As we More rise to the surface. The Galápagos Penguins’ Pacific climate deal is similar to ours – we’re not in control.
The thing is, the compromise [on carbon reduction] is between countries and not a compromise with the Earth and that’s really who you need the extension from. When you get an extension, it’s from the teacher. The other students can’t be like, the class decided we’re all getting an extension on this exam. We don’t want to take it until next week. And then the teacher is like, “well that’s cute … you all fail!”
― Hari Kondabolu, The Bugle, December 2019
In the deep waters of the mid-Pacific, there is gargantuan biomassThe weight of living organisms. Biomass can be measured in relation to the amount of carbon, the dry weight (with all moisture removed) or living weight. In general it can be used to describe the volume of energy that is contained inside systems, as the size of animals relates to their metabolism and therefore, how much energy they contain and More of foraging squid and fish. A voracious food chainA single thread in a food web illustrating the chain of animals that eat each other. At the base of the food chain are small high-energy (fast metabolism) animals and at the other end large low metabolism animals. An example would be whales eating krill that eat plankton that eat algae. Or lions that eat gazelles that eat grass. More generates huge quantities of decay and nutrients. If it were not for these massive currents, they would settle into the abyss. Though when they are swept into tropical coastal waters, which are traditionally resource poor, it nourishes the ecosystem. Ultimately the penguins’ favourite prey flourish and the penguins can enjoy a productive breeding season.
Life on the precipice of existence
Galápagos Penguins are limited to feeding only a couple of kilometres offshore. They also need waddle-able beach-access to colonies. These are distributed along less precipitous coasts of northern and eastern Fernandina and in the Elizabeth Bay area of Isabela. The western islands are closest to the current’s nutrientA substance that contains the raw materials for life. At a chemical level, these are contained inside compounds that are absorbed into the body and essential energy-containing molecules are extracted, so that energy can be transformed into other chemical processes that use the energy for living. More upwelling action.
Uncertainty about the strength of the current has meant that Galápagos Penguins have had to adopt more extreme survival strategies than their southern ocean counterparts. All other penguins have a specific breeding season, while Galápagos Penguins reproduce whenever conditions are favourable. Some years they may breed twice, other years not at all. Spreading out across different colonies means populations can ‘hedge’ survival risk.
Being ready to breed at any time, though, is a costly strategy but one that has served to maintain Galápagos Penguin populations.
A new survival outfit every year
One of the more energy-intensive tasks for any penguin is to moult its body feathers. This is also essential for survival. Moulting is really energy-intensive.It means replacing all feathers in one go while fasting on land for two weeks or more.
Galápagos Penguins lead a life of double jeopardy. Daytime air temperatures on the colony soar to 40ºC while water temperatures are as low as 20ºC. The internal temperature of a moulting bird in seawater can drop by six degrees in just 30 seconds. So, moulting is critical to maintain insulation – it’s literally the bird’s survival suit.
Galápagos Penguins have a serendipitous existence
Volcanic eruptions 4.2 million years ago created the Galápagos Islands. A new set of conditions for the rapid evolution of species, including Galápagos Penguins, started about 2 million years ago. Their appearance was premised on a geological twist of fate. A crack in the ocean crust appeared and lava was thrown up to create the islands, 1,000km from Ecuador.
These avian cast aways carved out a new ‘niche’ in the only way possible. Through hundreds-of-thousands of years of unintentional trial and error and the Galápagos Penguins’ Pacific climate deal. It’s almost unimaginable how they have persisted for almost two million years. That is what makes them among the most successful and exquisitely adapted species on Earth.
Ecosystems are far more than the sum of their parts
We cannot imagine the impact of Galápagos Penguins, which is why we should not imagine a world without them. The systems that sustain life on Earth are from processes so complex, we can never fully comprehend. Every animal is a part of that.
Galápagos Penguin teach us is that ecosystems are finely balanced around the interaction of animals with the environment: their ‘ecology’. This arises from influences at a bewildering array of scales from molecular to planet-wide. From the Galápagos Penguin to the animals and birds that live in your local park, we can build similar stories. After all, we all came from the same place. We share the same planet and we all depend on a fair climate for our survival.
References
1. Baker, A., et al., Multiple gene evidence for expansion of extant penguins out of Antarctica due to global cooling. Proceedings. Biological sciences / The Royal Society, 2006. 273: p. 11-7.
2. Steadman, D., et al., Chronology of Holocene vertebrate extinction in the Galápagos Islands. Quaternary Research, 1991. 36: p. 126-133.
3. Steinfurth, A. Marine ecology and conservation of the Galápagos penguin, Spheniscus mendiculus. 2007.
