A Perfect Planet

The animals that call volcanoes home

By Amy Nicholson

These incredible animals survive AND thrive near one of the Earth’s most powerful forces.

Volcanoes are one the planet’s most dangerous forces, yet some creatures have adapted and are thriving in these treacherous environments. Here are some of Earth’s most resilient wildlife...

Two lesser flamingoes feed their chick
Lesser flamingoes gather in huge numbers on Lake Natron to breed. © Darren Williams | Silverback Films 2019
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Lesser flamingo (Phoenicoparrus minor)

Ol Donyo Lengai in Tanzania is one of Africa’s most active volcanoes, and on it’s northern flank is Lake Natron. This is one of the world’s most toxic bodies of water, yet is home to a magnificent wildlife spectacle - a gathering and breeding place for two million lesser flamingos.

The water temperature of Lake Natron frequently rises above 40°C and is very alkaline due to the sodium carbonate and other minerals that flow into the lake from the surrounding hills. These conditions can burn skin, making it inhospitable for most plants, animals, and humans. The flamingos’ tough skin and scales on their legs prevent burns, and they have a unique ability to drink water near boiling point, and to remove salt from water using their nasal cavity.

Using these unique attributes, the lesser flamingo has made this infernal place their paradise. Free from most predators, the flamingos build their nests on small islands that form in the lake during the dry season. And with little competition for food, the flamingos have plenty of access to algae - their vital source of food found in Volcanic water.

Galapagos land iguana on crater edge
Female land iguanas have taken advantage of the thermal heat coming off the volcano and lay their eggs in its ash. © Tui De Roy | Silverback Films 2018

Galapagos land iguanas (Conolophus subcristatus)

Fernandina Island is the most active and most pristine of the Galapagos volcanoes, and is home to some of the Archipelago’s most iconic and endangered species, including marine and land iguanas, flightless cormorants, penguins and sea lions, all of which have learnt how to adapt and live in this remote territory.

Female land iguanas have taken advantage of the thermal heat coming off the volcano. Every year, nearly 2,000 of these lizards make the ten day trek from the coast to the top of La Cumbre, from where they then descend the precipitous slopes to the crater floor. Once at the bottom, they lay their eggs in the soft, warm ash, which is the perfect temperature for incubation.

The constant threat of eruptions, earthquakes and spewing lava make this climate treacherous for any species, especially ones nesting inside the crater, but the land iguanas are often able to sense increased volcanic activity, giving them time to descend to safety.

Vampire finch feeds on Nazca booby
These clever finches have become vampires in order to survive on a volcanic island. © Silverback Films

Vampire ground finch (Geospiza septentrionalis)

The volcanic island of Wolf in the Galapagos is hot and dry, and often there is limited food and water available to the species that live here. It has been said that during droughts the finch populations can decrease by 90%.

However, these castaway finches are clever and creative. They have evolved a distinguished behaviour and characteristic to survive, by turning into vampires! In order to supplement their diet of cactus nectar, pulp and the contents of bird eggs, the vampire finch also drinks blood. By adapting their technique of removing and eating parasites from booby seabirds that roost on the island, it uses its sharp beak to pierce the flesh so that blood is drawn. Drinking this means that the finch can consume all the nutrients needed to enrich its diet.

Due to this evolution, the vampire finch now has the largest and most pointed beak of all the sharp-beaked ground finch subspecies.

What’s interesting is it seems the boobys don’t put up much of a fight either, perhaps because it is an effective cleaning method for them, or because the vampire finches swarm in astounding numbers making it impossible to win a fight even if they tried!

Featured image © Renzi Tommaso | Getty