Strewn across the Indian Ocean to the east of Madagascar, the Mascarene Islands (Mauritius, Réunion and Rodrigues) are well known as the former home of the dodo and other strange extinct birds. However, dodos and their kin were only part of the unique ecosystem encountered by early visitors to these islands. As with Madagascar, the Mascarenes had been geographically cut off from the rest of the world for millions of years prior to human discovery. This isolation combined with their tropical location to produce an abundance of singular forms.

Today it is hard to imagine an environment virtually unaltered by human activity, so thorough has our species’ effect on every part of the biosphere been. Even in 1598, the year in which present-day Mauritius was named by the Dutch, such a task would have been difficult. In fact the Mascarenes were the very last sizeable tropical islands to be settled by humans. Though the Renaissance-era Dutch sailors who stumbled ashore on a warm September day had no way of knowing it, they would be amongst the last humans in history to behold the full splendour of what evolution can conjure on a good-sized tropical canvas.

The Dutch landed in a mountain-ringed bay draped in thick forests, home to well over one hundred times as many endemic flowering plant species as mainland France in an area less than one two-hundredth of the size. Within the forests roamed an array of island oddities. Besides the famed dodo, bulky broad-billed parrots lumbered through the undergrowth, whilst navy-blue pigeons perched above, puffing out crests of slim white feathers. The largest animal inhabitants of this paradise were the giant tortoises (genus Cylindraspis), of which five species were scattered across Mauritius, Réunion and Rodrigues. Giant and unafraid of humans, these creatures made quite an impression on the Dutch, as shown in this fanciful 1601 engraving of mariners riding (a ridiculously oversized) one.

French and Dutch settlers arriving on Réunion and Rodrigues in the seventeenth century found great herds of native tortoises. One early arrival on Rodrigues described whole fields covered in the creatures! Unfortunately for all five Mascarene giant tortoise species, their large size combined with apparent tameness and slow movement to render them ridiculously easy prey. Before refrigeration, islands served as gigantic larders for malnourished and hungry sailors. Faced with abundance, humans responded as they so often have: with rampant plunder.

The slow metabolic rate of the Mascarenes’ biggest natives counted horribly against them. Able to survive without food or water for months on end, they were viewed as an ideal food source, to be loaded alive en masse into ships’ holds. Thousands of captive tortoises died before they could even be eaten, since their shells had diminished in thickness due to an absence of native predators, causing many to be crushed to death within the stockpiles.

Our species’ fixation with oil also played a part in the demise of these animals. Long before the petroleum era, humans already lusted for the substance, searching for it inside living creatures. One seventeenth-century Mauritian governor reports a grisly tableau of dead and dying tortoises with holes smashed into their shells in search of fat to be boiled down. Apparently, up to fifty might be slain before a single fat individual was found, with each barrel of “tortoise oil” requiring the deaths of at least 400 fat testudines.

Unsurprisingly, such wanton slaughter soon turned beguiling plenty into vanishing rarity. Even by the standards of a Europe that burned, beheaded and hanged tens of thousands of its own as witches during this period, the treatment of Mascarene tortoises was seen as reckless by officialdom. As early as 1639, legislation was put in place on Mauritius to protect its tortoises. Sadly this proved ineffective and it would not be until 1771 that the remaining tortoises would receive meaningful protection.

It is unclear exactly how many of the original five species remained extant by 1771. Certainly the number of survivors would have been very low. The bountiful lands of Mauritius, Réunion and Rodrigues had largely been laid waste by slash-and-burn deforestation, with feral cats and pigs wandering freely amidst remaining tortoise nesting sites.

During this twilight of the tortoises, a handful of scientific observations were made, including at least one image of a live animal. That 1792 sketch, reproduced below, shows a Réunion giant tortoise. It was the largest species, capable of growing over a metre in length.

Tantalising scraps of evidence, including an alleged photograph of a living tortoise, survive from the late nineteenth century. However, the last generally-accepted record of Mascarene giant tortoises was in 1844. A British expedition to Round Island, off the coast of Mauritius, found several living tortoises. A female was captured and laid eggs, with the hatchlings distributed amongst various friends of one of the explorers. There is no information available as to which of the two Mauritian species was found on Round Island, nor is there anything known about what became of the hatchlings. Given that goats and rabbits were introduced to Round Island shortly thereafter, it is probable that one of the hatchlings became the endling of the genus Cylindraspis.

Disappearing when they did, at a time when modern science was still emerging, the Mascarene giant tortoises occupy a strange halfway house between poorly-understood human-induced casualties of the early modern era and better-known lost species of more recent times. Unlike some of their vanished compatriots, such as the Mascarene grey parakeet, their life appearance is fairly well-known, but there is still a deep air of mystery about them. The world’s only taxidermied specimen is kept in Paris, in the sombre setting of the Room of Endangered & Extinct Species. Below is a (slightly blurred) picture which seems a poignant reminder of these peculiar giants, now forever receding into the mists of time.

Images: Public domain