This week, we’re pleased to welcome Becky Taylor as our guest blogger. Becky has just returned from doing fieldwork on Ascension Island, and is excited to share her experience with us! For more information about Becky, check out her bio below.
“Like nowhere else on earth.” That’s what all the leaflets say about Ascension Island – and they are definitely correct. Ascension Island is one of the most remote places I have ever had the pleasure of visiting: a small volcanic island quite literally in the middle of the ocean. Most people have never even heard of it, let alone know where it is. Formed by the volcanoes along the mid-Atlantic ridge, it is situated midway between Africa and South America in the south Atlantic Ocean, just below the equator.
Despite its remote location, Ascension Island has a fascinating history. Discovered in 1501 by the Portugese, it went unclaimed for hundreds of years – it was just too barren to be of interest to colonial powers. Occasionally, sailors would stop by on their way across the Atlantic and nab a sea turtle to snack on, but with little fresh water available at the time, no one bothered to settle there. However, things changed in 1815, when Napoleon was defeated in the Battle of Waterloo. After his defeat, he was exiled by the British to a remote island called St. Helena – which just happens to be a neighbour of Ascension Island. The British were worried that Napoleonic sympathizers might try and stage a rescue from Ascension. To prevent this, they claimed and garrisoned Ascension – and it remains a UK territory to this day.
So the British found themselves in possession of a barren, arid island in the southern Atlantic. But far from being discouraged by its inhospitable nature, they took it as a challenge, and immediately set about changing it. In 1836, the HMS Beagle landed on the island, carrying, of course, naturalist Charles Darwin, who noticed how dry and barren the island was. Seven years later, in 1843, a friend of his also visited the island: Joseph Hooker, a botanist who also happened to be the son of the director of Kew Gardens. After hearing about the island from Darwin, he hatched a plan. He began to ship trees from England to Ascension, with the help of the British Royal Navy and Kew Gardens. Thousands of trees and plants from all over the globe were sent to Ascension, and planted onto what was then known as “the peak”, the highest point on the island.
Today, “the peak” is known as Green Mountain, and has undergone a complete transformation from its original arid state. Green Mountain is now home to an entirely man-made and now self-sustaining cloud forest environment. It was the first experiment in terraforming: the deliberate alteration of an environment to make it more hospitable to humans.
Many people consider Green Mountain to be an inspiring success story, and there is no doubt that it is scientifically fascinating. However, there are always costs associated with massive changes like this. Ascension Island’s endemic plant species did not cope well with the changing environment. There are now only 7 of these endemic species left on the island – all of which are listed between Vulnerable and Critically Endangered on the IUCN Red List. Conservation efforts are currently under way to attempt to save these unique species.
But while the changes were detrimental to some of Ascension’s endemic species, one of the island’s inhabitants was all for the transformation of Green Mountain: the land crab, Johngarthia lagostoma. Today, these crabs live at the top of the peak – a strange place to find crabs, particularly because their larvae are marine. So once a year, between January and March, these crabs undertake an epic journey down the mountain to the sea to mate – and then they trek back up the mountain again. They travel up to 1,400 ft. per day, an impressive feat for such small creatures. They come out at night, and have a tendency to wander onto the island’s roads in the dark. Luckily for them, the island’s inhabitants love them and will go out of their way to prevent running them over – whether that involves simply swerving around them, or getting out of the car to chase them out of the way.
Beyond the land crab, Ascension Island is home to a fascinating cast of characters. It hosts a variety of seabird species, which breed on Boatswain Bird Island, just off the main island. And of course, you can hardly write about Ascension without mentioning the sea turtles. The island is an important green turtle nesting site. The green turtles found on Ascension are apparently the largest of their species, and they migrate more than 2000 km to get there – all the way from the coast of Brazil. Between December and June, the females heave up onto the island’s beaches to lay their eggs, which hatch 50-60 days later.
Wandering along the beach one night at sunset, I was lucky enough to see a green turtle nest hatching, and watch the hatchling turtles run down the beach to the ocean. I was so excited by the encounter that I ran straight to the conservation team to tell them what I had seen – only to find out that my exciting sighting was common on Ascension. The conservation team was pleased for me, but nowhere near as excited as I had been. More than anything, it was their attitude that made me realise: Ascension really is like no place on earth.
Becky completed her BSc in Biology at the University of Bristol, UK in 2010, and then worked for the conservation charity Wildscreen on their ARKive website for two years before deciding to undertake her MSc at the University of Exeter, UK. She started her PhD at Queen’s University in September 2013. She is currently researching the genomics of the evolution of seasonal populations of the band-rumped storm-petrel (Oceanodroma castro), and aims to create a comprehensive phylogeny of this cryptic species complex.