The World’s Rarest Tortoise [Astrochelys yniphora]

According to Owen Griffiths, Managing Director at Bioculture Group in Mauritius, “The ploughshare isn’t the flashiest tortoise on the planet”. And he’s right. Compared to its compatriot, the radiated tortoise, the ploughshare looks decidedly drab. But this tortoise isn’t sought after for its looks.

To halt the population’s decline, a group of ecologists and conservationists recently embarked on a mission to capture every remaining ploughshare tortoise left in the wild in a bid to make them safe from poaching and smuggling. Three months later they had collected a total of eight animals, all of which were destined to enter a captive-breeding program in a last-ditch attempt to save this tortoise from extinction. “A recent presentation by the Durrell Wildlife Conservation Trust estimated there are only around 100 ploughshare tortoises left in the wild today,” warns Owen. “It’s a race against time.”

First described in 1885 by French herpetologist Leon Valliant the ploughshare tortoise was originally called Testudo yniphora, with the name referring to the ploughshaped section of shell underneath the neck. Endemic to Madagascar, it is the largest surviving tortoise on this giant island since the Aldabra tortoise went extinct there. Male ploughshares can reach over 20kg, although 10 – 15kg is a more common size for an adult male, but nevertheless significantly larger than their female counterparts. Large males tend to out-compete smaller rivals when mating, and are also able to more easily mount females thereafter.

Ploughshare tortoises are listed as ‘critically endangered’ by the International Union for the Conservation of Nature – just one category away from being extinct in the wild.

The demise of the Ploughshare

Ploughshare numbers in the wild were rapidly falling as early as the late 1980s. Unlike most other endangered species, the primary cause of the ploughshare’s decline isn’t habitat destruction. While mining, construction and hardwood deforestation are beginning to play a role in the ploughshare’s fight against extinction, the cause of their demise historically has been the trade in bushmeat and, more recently, poaching to supply the pet trade’s demand for the world’s rarest tortoise.

By 1975 the ploughshare had been protected both nationally and internationally, as well as being attributed CITES Appendix I status, thereby essentially banning trade in the species. “You’ll go to jail if you’re caught illegally in possession of a ploughshare,” explains Owen.

This rarity and infamy served only to create a demand among animal collectors, particularly in the newly affluent countries of East Asia, where it was estimated that up to 50 smuggled ploughshares were being sold illegally each year. Illegally exported ploughshares have also found their way to animal collectors in Europe.

As with all things, the laws of supply and demand are the driving forces behind this illegal trade. As a species becomes rarer, the demand for these animals often grows and the specimens left in the wild became more valuable. A ploughshare taken from the wild could earn $1000 for an average Malagasy worker, more money than most could hope to earn in a year. For workers struggling to earn enough money to feed their families, the incentive to break the law is irresistible. This also extends to the transportation hubs through which the Ploughshare tortoises are smuggled, both in Madagascar and in the more affluent countries where the animals are destined.

“You can’t really blame the locals,” explains Owen. “The catalyst for poaching and smuggling ploughshares is the demand from richer countries. Until the supply and demand issue is balanced, we’re going to have a problem with illegal trade.”

Smuggling case study

Ploughshares in captivity

Breeding groups of ploughshare tortoises almost certainly exist in East Asian countries where hundreds of animals have been illegally imported over the last few decades. There are also a handful of ploughshare tortoises owned by individuals which were exported legally from Madagascar before trade restrictions were implemented, although these are thought to be single animals and not part of any captive-breeding initiative.

Saving the ploughshare

According to Miguel Pedrono and Alison Clausen’s 2017 book ‘Twilight of the Angonoka’ there are only a handful of projects in the world working to propagate ploughshare tortoises – comprising 75 animals in total and distributed across 13 collections. The Turtle Conservancy project runs the American Zoo Association studbook for the species and has been working with them for almost a decade, although their team has links with ploughshares going back to the late 1960s. Nogeyama Zoo in Yokohama, Japan, successfully bred three ploughshares in 2016, being the only institution to breed this species outside Madagascar – until recently.

But the shining light in the quest to save the ploughshare is The Durrell Wildlife Conservation Trust based at Jersey Zoo, which has been hugely instrumental and successful in many respects. Gerald Durrell’s visit to Madagascar in 1990 caused him such concern for the plight of the ploughshare that he established a breeding centre with backing from the Malagasy Government. The project was a resounding success producing hundreds of babies over the course of just a few years, most of which were released into the wild under close scientific scrutiny and monitoring. Unfortunately, the project has also been beset by misfortune, criminal activity and tragedy.

The great ploughshare dispute

In May 1986 the Durrell Wildlife Conservation Trust’s ploughshare breeding facility was dealt a blow when thieves broke into the heavily secured compound and four adult breeding ploughshares were stolen. The culprits were never caught.

Poaching and smuggling also affected the project’s success as baby ploughshares released from the facility started turning up in the pet trade over the next few years. Many still contained the Durrell Institute’s subcutaneous ID chips. In 1999, 33 Durrell-born ploughshares turned up in Holland. The animals were seized and sent to Bronx Zoo in New York under the care of renowned herpetologist John Bailer while the animals’ fate could be decided. The Malagasy Government rightfully decided that, because the animals had likely been kept with other species of tortoise while they were in captivity, the ploughshares could not be repatriated to the wild as the risk of transmitting pathogens into the wild population was too great.

However, the tortoises were still officially the property of Madagascar, and it was eventually decided, after much dispute, that the animals should be sent back to Madagascar. The Durrell Institute didn’t want the animals, fearing the same disease transmission risks that prevented their release into the wild, so the ploughshares were eventually flown to Madagascar and would be placed in the care of Olaf Pronk, a well-known animal dealer based in the Malagasy capital of Antananarivo. While the ploughshares would always belong to the Malagasy Government, Pronk would care for them at his facility.

Bailer was furious the tortoises would be put into the care of a pet-trade dealer. So, before they were packaged for transportation, Bailer set about the tortoises’ shells with an engraving tool, etchin ‘MEF’ (for Ministry of Eaux et Forets) on each, thereby making the animals seemingly unsaleable. The tortoises were returned to Madagascar, only to make an appearance later in this story.

A deadly mistake

In the meantime, security and the fear of theft surrounding the Durrell ploughshare breeding facility had become a major concern, with everyone involved in the project on high alert. In late 1996, Don Reid, a senior herpetologist on the Durrell Institute project, noticed a car cruising the roads in the national park near the breeding facility – a highly unusual and suspicious activity in Madagascar, where few people venture outside after dark.

After calling in the Madagascan armed police, the team intercepted the car, finding a group of German herpers on a recreational field trip. From here, it’s difficult to corroborate the details, but the story as we understand it is that one of the herpers took a photograph of the confrontation. The flash of the camera spooked one of the young police officers, causing him to open fire, killing two of the Germans.

By all accounts, it was a tragic and deadly misunderstanding caused by paranoia, panic, herp tourists and an inexperienced police officer.

These animals were seized from a smuggler bound for East Asia.

The Rodrigues Island project

The Francois Leguat Giant Tortoise and Cave Reserve ploughshare breeding project on the tiny island of Rodrigues is part of a much larger conservation initiative undertaken by Owen Griffiths in conjunction with the Madagascan Government.

Owen’s conservation work in Madagascar reaches back more than 20 years and has culminated in several projects which conserve and protect the island’s endangered flora, fauna and habitats. Over the last two decades, Owen has invested a significant amount of money developing conservation initiatives in Madagascar, Mauritius and Rodrigues island.

In addition to planting some 200,000 endemic trees across 40 hectares in Mauritius and 300,000 trees on 20 hectares on Rodrigues Island, Owen has also developed several forest restoration projects in Mauritius, working on returning previously ruined habitats to their former glory by weeding out exotic invasive plant species and replanting with natives. He is also heavily involved in habitat conservation in Madagascar.

One feature of the Rodrigues project focused on the re-wilding of Aldabra and radiated tortoises and, with a team of biologists, keepers and other staff on board to help, both tortoise species bred prolifically. While radiated and Aldabra tortoises are not native to Rodrigues, they replace similar species which were wiped out by humans in the 1780s. “We can’t re-introduce extinct species but can introduce similar analogue species to fill that ecological gap and re-establish a biological balance,” says Owen.

But where does the ploughshare fit into this complex and politically sensitive project?

Owen picks up the story: “We essentially left the radiated and Aldabra tortoises to their own devices and the success of the project is almost entirely because they are under such natural conditions. With the Aldabras and the radiateds doing so well, we began to think that perhaps this was an opportunity to do the same for ploughshares. And in 2015, we got the chance to make it happen.”

Breeding ploughshares

We have met most of the ploughshares at the Rodrigues Island facility in this story before. Remember the
smuggled tortoises which had their shells engraved at Bronx Zoo after being seized in Holland? These animals were eventually repatriated to Madagascar and placed in the care of animal dealer Olaf Pronk. Since 1996 all but 12 of the 33 repatriated ploughshares had died. In 2015, those that were still alive were relocated to Rodrigues to form the basis of Owen’s breeding project.

Despite their age, there were no mature males in the group, so a large male was kindly donated by the Durrell Institute from their breeding group. A further three baby ploughshares were sent to Rodrigues following a seizure
in Mauritius of smuggled animals bound for East Asia, creating a group of 16 ploughshare tortoises.

“The animals and the land the facility is built on are both owned by the Rodrigues Island Government and we are simply custodians,” explains Owen. “The short term goal is to create a significant captive population with the hope of eventually being able to return animals to the wild – if that is indeed possible. There are several projects in development as we speak which could jeopardise the remaining wild habitat into which tortoises could be released.”

Baby ploughshares born at the Rodrigues Island breeding project.

Baby tortoises

The first year of the Rodrigues Island project in 2017 was unsuccessful and the newly introduced ploughshare herd produced only infertile eggs, likely due to the disruption of moving animals from one location to another. But the 2018 – 2019 breeding season was more of a success, resulting in over 80 eggs being laid. Each nest was monitored 24/7 until 8 babies were hatched and collected.

The natural conditions enjoyed by the tortoises on Rodrigues even extends to the egg incubation process. Unlike the ploughshare breeding projects in Madagascar and Japan, the eggs aren’t excavated or artificially incubated. Eggs are laid wherever the female decides is a good spot, and there they are left to incubate naturally.

The ploughshare breeding and tortoise re-wilding projects on Rodrigues have been a success story, not just for the tortoises, but for the whole ecosystem of this tiny island. The initiative is funded through tourism, with a select number embarking on supervised guided tours to see the reserve’s unique fauna and flora close up. The island receives around 25,000 visitors each year, all of them eager for a chance to see the unique and fascinating ecosystem. It’s a great example of how a well-run project can bring benefits in many different ways.



The breeding facility is heavily guarded and robustly secure. In 1997 one of the project’s other locations on Mauritius suffered the theft of over 100 baby Aldabra tortoises, so Owen isn’t taking any chances. Security guards patrol the compound day and night and have a direct relationship with the area’s armed police force.


While the ploughshare story so far sounds like it has a happy ending, the species still faces enormous challenges. Many organisations and individuals are ferociously against any ploughshare tortoises being made available to the pet trade, despite the seemingly robust rationale behind that idea. Rather than fuelling pet-trade demand which would result in more smuggling, research shows that such a move would, instead, sow the seeds to satisfy the demand with captive-bred animals, thereby making smuggling impractical and financially unviable. Smuggling animals is only viable if they are cheaper than captive-bred ones.

But the next challenge facing the ploughshare is the same as that which faces many endangered animals – habitat destruction. “If there’s one thing the Rodrigues Island project has taught us about ploughshares, it’s that they are not at all difficult to breed,” stresses Owen. “Our challenges, and those of the ploughshare, are entirely political.” With industry and the struggling Malagasy economy making demands on the ploughshare’s remaining habitats, returning tortoises to the wild looks like it will be a monumental struggle. At the moment the ploughshare tortoise will likely go the same way as the golden lion tamarin – another species that thrives and breeds prolifically in captivity, but is all but extinct in the wild due to habitat destruction. Hopefully, the success of the Rodrigues Island project can carve a niche for the ploughshare tortoise to inhabit, but only time will tell.

In the meantime, Owen and his team are doing all they can to ensure the ploughshare tortoise is firmly
established in captivity. And that’s vital because, at the moment, it seems this species has no safe place to call its own in the wild.

This article was featured in our first issue of Exotics Keeper Magazine in November 2020. For more, including electric blue day geckos and keeping armadillos, you can purchase this issue from our store.

The World’s Rarest Tortoise [Astrochelys yniphora]

Species Profile

Common Names
Ploughshare Tortoise
Angonoka Tortoise

Scientific Name
Astrochelys yniphora

30km radius in North-Western Madagascar

Males: 10-15kg
Females: 9kg

Fibrous grasses
Fallen fruit

Over 100 years
Oldest captive individual: 79 years old

Up to 4 clutches of 6 eggs per season; often fewer

IUCN Red List Status
Critically Endangered

Most of the tortoises seized before being smuggled out of the country are found in relatively small numbers – either a handful of adult tortoises or, less frequently, a few dozen babies packed tightly in a suitcase. However, a recent seizure of radiated tortoises found over 17,000 animals in a property owned by a former minister in the then Malagasy Government. The minister in question showed that the property was rented to someone else and that he had no knowledge of the animals. The convicted perpetrators recently received a six-year jail sentence and a significant monetary fine.

LEARN MORE: Miguel Pedrono and Alison Clausen’s book Twilight of the Angonoka is the go-to reference for this iconic species.

Let's Get Social

  • Social Media:

Related Posts

Weird & Wonderful Vol 12: Reticulated siren [Sirenidae]


Find Out More Read Full Story

Weird & Wonderful Vol 11: Feather Stars [Crinoids]


Read about the unusual feather stars - Echinoderms that start life on a stalk, like a lily, and become mesmerising drifting adults.

Find Out More Read Full Story

Weird & Wonderful Vol 10: False gharial [Tomistoma schlegelii]


You may have heard of gharials, but did you know there is a close relative - the false gharial? Tomistoma, as they are also called, are endangered in the wild as well.

Find Out More Read Full Story