Where Is Aldabra?

“Aldabra is one of the wonders of the world”. Sir David Attenborough

 

    The Aldabra Atoll, home of the Aldabra Giant Tortoise is in the Indian Ocean, off the east coast of Africa, at a 9 24 degree Southern Latitude, 46 20 degrees Eastern Longitude. It is a place reminiscent of when dinosaurs ruled the world. Millions of years ago giant tortoises roamed almost everywhere, mainly because the continents were joined. It is thought that Aldabra Giant Tortoises have been in the West Indian Ocean region for around 40 million years and two of the founding migrations have come from the African East coast. However, by the end of the last ice age competition and predation from mammal and humans had made them almost extinct.

   In 1509 Aldabra was documented for the first time, on a Portuguese map of the area around Madagascar, however, a group of Arabs is actually thought to be the first known people to discover Aldabra during an exploratory trip in the Indian Ocean, nearly 600 years earlier in 916 AD. The name Aldabra is reported to have come from the Arabic word Al-Khadra, which means The Green, in reference to the lagoons green reflection on the clouds above it. An alternative suggestion is that the name was derived from the star Aldabaran, which was used by early Arab sailors to chart their sailing course.

   In 1742, as the Islands of Seychelles were seized by the French, when Captain Lazard Picault was sent to Seychelles and to Aldabra to assess their potential, this was the first recorded visit to Aldabra. On Aldabra, the crew were astonished by the size of the giant tortoises and valued them as a source of meat, but they found the granitic islands of the Seychelles more useful and Aldabra was considered not good for anything. The remote location of Aldabra and the harsh environment deterred permanent human settlement for many years. This is not to say however, that it did not escape exploitation despite Picaults early derogatory assessment of the Atoll.

  Aldabra is 700 km (about 427 miles) East of Tanzania, on mainland Africa. It is 285 miles from northern points of Madagascar to the Aldabra Atoll, which was its closest inhabited neighbour. However, with luxury development happening on nearby Assumption Island, about 70 miles away, that is about to change, as humans encroach near and nearer to the isolated island. Aldabra is the most south westerly Atoll amongst the Islands known as The Seychelles. Official business is all done from Mahe, the capital of the Seychelles, which is 760 miles away, and not from the closer Madagascar.

  Being located nearer the equator, the weather is opposite to the UK. There the average temperatures range between 22 to 31 degrees Celsius and it is cooler in August and warmer in December.

  Aldabra is only 8 metres (26ft) at its highest elevation above sea level, a lot if it is just 2m or 4m above sea level., and so is at great risk from rising water levels caused by climate change. It is possible that Aldabra will be completely submerged by the year 2100, if sea levels continue to rise at the rate scientists fear they will. At the very least, the current sea level rise is poised to drown substantial parts of the Atoll within the lifespan of the tortoises living on Aldabra today

   The island is the worlds 2nd largest coral Atoll and is about 34km (21 miles) long by 13 km (8.1 miles) wide, which is just a little thinner but about the size of the Isle of Wight.  An Atoll is a ring shaped Island, including a coral reef, which encircles a lagoon. The largest coral Atoll in the world is The Great Chagos Bank in the South China Sea, near the Philippines.

  Unusually the Aldabra Giant Tortoise is top of the food chain there, but as there are no apex predators on the Island this large reptile has become the most influential animal on the Atoll. They perform a similar function as to an Elephant on the African mainland. They are used by many plants as a valuable method of pollination because they browse food, grasses, trees and bushes and then distribute the propagated seeds, via their poo, after they pass through its digestive tract, across the island. The seed is ready to germinate by the time it comes out of the Aldabra after being digested and passed out in their poo, and it is generally much cleaner than when it sent in. Such is their influence that their intense grazing actions have put pressure on natural flowers to alter the way they pollinate, so the tortoises cannot take flower heads off too soon, making them directly responsible for plant evolution taking place.

  Also, The tortoises are fundamental in how the landscape looks and develops, as their big bodies lumber about they also forge pathways and corridors, through the undergrowth allowing smaller species ease of movement too. A bit like The Highways Agency putting in new road systems! Their grazing keeps everything under control, even knocking down small trees and shrubs, allowing light to get to the surface and encourage new plants to grow, they are what is described as a keystone species.

  Aldabra is part of the Seychelles outer islands, an archipelago of coral Atolls and islets. It is a harsh place to live, with low amounts of food available to them and even less access to regular fresh water, for that they have to wait for the monsoons to arrive. Monsoon season is November to March. However with 300 miles of open water, with strong currents, surrounding them there is no where else for them to easily go, there is no option other than wait and hope to survive.

  In 1811 the French lost Mauritius and Mahé to the British, and Aldabra became a British dependency governed from Mauritius. Then in 1874, the authorities on Mauritius announced their intention to begin commercial activities on Aldabra with a mangrove wood cutting and timber industry. However, Charles Darwin, along with other outstanding British naturalists of that time (including Thomas H. Huxley, Joseph Hooker, J. Kirk, Alfred Newton and Richard Owen), stated their grave concern about the effect of such an industry on the giant tortoise population of Aldabra and as a result the Governor of Mauritius abandoned the timber industry proposal.

  In 1879 an attempt was made to settle the Atoll by a party of 27 adults and 13 children, all Norwegians from Bergen, who arrived via Madagascar to found a community on communistic principles. This scheme failed because the group disbanded before even reaching Aldabra; when they learned the truth of the harsh environment on Picard, they changed their destination.

  The first settlement was finally built on Ile Magnan in 1888 at the West channel of Aldabra by the lessee Jules Cauvin. He came to exploit the Atoll for mangrove timber, green turtles and fish and also tried to plant coconuts. As leasers changed, other commercial exploits, such as cotton and sisal production, were also attempted unsuccessfully. These settlers also released domestic animals such as pigs and goats on the Atoll. The mainstays of successful human exploitation through this time were fishing, timber and sadly the harvesting of Green Sea Turtles and giant tortoises for their meat, which dramatically reduced their numbers.

   The Atoll of Aldabra consists of 13 limestone islands, of varying sizes and heights, which are the result of ancient volcanic or seismic activity. It was formed about 125 million years ago when the volcano first erupted and material was deposited on the sea bed, the eruptions continued to grow until the cool larva finally it broke the ocean surface. Coral grew around the island at sea level and when the old volcano subsided beneath the sea, a coral Atoll was formed.

  The land contains varied habitats consisting of large mangrove swamps, which provide vital shade for the tortoises in the hot temperatures and these mainly border the lagoon which they love to wallow in through hot parts of the day. Millions of tonnes of water rush in and out of the lagoon twice every day, however, the tidal water is also teeming with Black Tipped Reef Sharks and Manta Rays. The sharks use the mangrove forests, in the lagoon, as a nursery for their pups, they only produce a few young at a time and are classed as near threatened by the IUCN.

   Scrub forest peters down to grassland and then to the coastal dunes edging the largely inaccessible Atoll, thanks to the coral reef which goes around most of the island preventing boats from getting too close. It is these reefs that helped to protect the Islands inhabitants from the plundering sailing ships of the 18th and 19th century.

  The lagoon connects with the ocean in only 4 places, where there is a gap in the coral reef, so there is very limited access to the internal areas. This water area is so big that Mahé, the largest inhabited island of Seychelles, would actually fit inside this lagoon.

  Aldabra Island has 4 main Islands, North or Middle Island also known as Malabar. Grand Terre, which is the South Island and is the largest. Polymnie, and a small settlement island called Ille Picard or West Island, where the research station is located. Tortoises are most plentiful on South Island but a few live on North and West. Researchers have found that tortoises on Malabar and Piccard average twice the size of the ones on Grand Terre and also lay 3 to 4 times as many eggs per clutch.

  The coastline is approx 50 miles long with only about 1% of it being beach, which is so vitally important for the Green Sea Turtles. The rest is nearly impossible to cross on foot and because of this it is quite difficult to even get around the Atoll, it has remained largely uninhabited and the giant tortoises have been free to colonise it and become the largest occupants.

  It is not just the Giant Tortoises that are of unique importance to the area. Reportedly there are 307 different species of plant and animals on Aldabra, including one of the largest populations of nesting Green Sea Turtles in the Western Indian Ocean and these lay their eggs on the small beaches. In 2011 a paper published on the nesting Green Turtle showed an increase of 500 to 800% in last 40 years, which can definitely be heralded as a success for conservation and we can only hope these levels continue in future years. Unfortunately their nesting beaches are under jeopardy from plastic pollution being washed ashore, making it very difficult to haul themselves out onto the beaches and forcing them to clamber over it, risking injury, as they try to get to their nesting area.

  Several invasive species have been introduced to Aldabra, over the years, since man first began to step ashore, some of it was accidental, some more deliberate. These alien species prey on the native wildlife and fauna affecting the biodiversity of the area. An example is feral goats which would compete with the tortoises for foliage and grass, these were finally, successfully, removed in 2012 after an intensive period of tracking, and elimination, completing an eradication programme that lasted for more than a quarter of a century. Seychelles Island Foundation, who are now in charge of Aldabra Atoll, is researching method to eradicate more of these threats, such as rate and feral cats, who both target youngsters, and some progress has been made.

  In 1962 the British government commissioned a secret military survey of Aldabra and other western Indian Ocean islands. In April 1965, The Times of London newspaper reported that Aldabra, Diego Garcia and Cocos-Keeling were being considered as sites for a future Anglo- American military base. Conservationists in Seychelles and in the international community, spearheaded by the Royal Society of London were outraged at this proposal an it became known as The Aldabra Affair, led by Professor David Stoddart, they successfully campaigned to save Aldabras unique fauna and flora from the encroachment of military technology which would have likely resulted in their decline and extinction. In 1967 the plans for a military staging post were abandoned much to the relief of conservationists, scientists and supporters around the world.

   After this the scientific interest in Aldabra increased and its value was recognized by the Royal Society, who planned and carried out a series of exploratory visits. In 1971, members of the Royal Society established a scientific research station on Aldabra near to the old settlement on Picard Island. The next few years were a time of intense scientific research and discovery with many scientific papers published on the unique flora and fauna of the Atoll.

  In 1979 the Seychelles Islands Foundation (SIF) was established as a public trust by presidential decree and was mandated to manage and conserve Aldabra. The SIF manages and protects the UNESCO World Heritage Sites of Aldabra Atoll and the Preslin Island nature reserve, Vallée de Mai, home to the unique Coco de Mare, the double coconut, and has the President of Seychelles, as its Patron.

  In 1996 SIF initiated the complete renovation of the Aldabra research station and field camps around the Atoll. In the past 30 years considerable scientific research has been undertaken at Aldabra with many scientific papers published, some following on from the earlier initial research of the 1970s. SIF has also developed and sponsors an education and outreach programme making Aldabra accessible to visits from Seychellois schoolchildren so they too can be inspired by this incredible place. After all it is the locals who are going to be looking after it in the future and they need to be inspired by its unique magic, to care and fight to keep it undeveloped.

  Whilst the Giant Tortoise may be the most famous resident of Aldabra there are other native species who are being reintroduced, studied and brought back from the brink of extinction. One success story began in 1999, when 18 flightless Aldabra Rail were reintroduced and after only 12 years there was an estimated population of 2765 of these birds.

  Sadly, in 2007 the Banded Aldabra Snail was declared extinct on the Atoll. However, to the scientists amazement and delight, in 2014 it was rediscovered on the northern island of Malabar.

  Aldabra is situated close to one of the busiest shipping routes in the Indian Ocean. In 1982, was inscribed as a UNESCO Marine World Heritage Site and The International Maritime Organisation has listed the Atoll as an area to be avoided by all ships. Recently the Seychelles Island Foundation has extended outer edge of the marine protection zone, in the sea, to 40km, to give the Atoll even greater protection. However, there is still a real possibility that if an oil tanker sustained any damage in this area, the subsequent oil spill could have devastating consequences for Aldabras wildlife. In more recent times local boat captains have been seen to be ignoring this protection zone and taking their wealthy clients closer and closer to the Atoll. thus increasing the chances of a new bio hazard making it ashore and increasing the chances of poaching taking place.

  Aldabra is a site of global scientific interest but its remote location makes operational management, and security protection, a major logistical challenge. In 2008, SIF started to investigate ways to increase energy efficiency, and develop a renewable energy system, instead of using the traditional diesel generators which were costly to run; aiming both to reduce operational costs and their environmental impact. A 25 kWp hybrid photovoltaic-diesel energy system was installed in 2012. In the first year of operation, 94% (38,171 kWh) of the stations electricity demand was generated by the new solar power system. This contributed to a significant reduction in CO2 emissions (a total of 97,523 kg of CO2 per year were avoided, of which 59% resulted from investments into energy efficiency measures and 41% was contributed by the PV system) and subsequently the research stations carbon footprint was largely reduced. Since implementation of the photovoltaic system, their diesel demand has decreased by 97% which will lead to a projected saving of €68,000, resulting in a system payback time of only three years.

  For anyone wishing to visit Aldabra, it is important to realise that the Atoll has no airstrip, no harbour or jetty and no helipad. There is no hotel or guest house and Aldabra is not set up to accommodate general visitors. All visitors on live on board the vessels that they arrive on but the activities of such vessels in this region have been severely compromised by an increase in piracy in the area in recent years.

  Modern day piracy is a big problem in the Western Indian Ocean and their increased threat in the area, for the last 5 years has reduced tourism in the outer Seychelles islands and this means there is less money coming into the area. The cruise ships and dive vessels are keeping well clear, which means the research station on Aldabra receives less funding, raised from the ticket sales at the Preslin Island nature reserve, Vallée de Mai, and from other aspects of the tourism dependent area.

  Improved vessel security and enforcement in the region is gradually lessoning the threat and impact but it will be a slow journey to recover its popularity. One of the downsides of the tourism to the area is the increase on rubbish that pollutes the ocean. The Aldabra clean up project was first launched in 2018 and when a second clean up took place in early 2019, they collected over 25 metric tonnes of marine plastic litter, during the five week expedition. However, in 2023 an estimated 513 tons of plastic was polluting Aldabra. This can be intentionally dumped at sea items, coming from the ships or illegal waste dumping, or things that have been washed away in bad weather. Ranging from commercial shipping gear, to the every present plastic bottles, in all sizes and forms, to more personal items like flip flops.

  More information on Aldabra can be found at the website for Seychelles Islands Foundation (SIF) www.sif.sc

More information on the plastic clean up can found at www.plasticodyssey.com

 

 

A Layout Of Aldabra Atoll Showing The Types Of Vegetation That Grow There. Most Of The Giant Tortoise Population Live On The South Island of Grand Terre, which is the largest island to the south.

 

Where Did The Tortoises Come From Before They Landed On Aldabra?

  Several species of giant tortoise inhabited the Islands of the western Indian Ocean until the middle of the 19th century. The MascareneGiant Tortoises  (living on Mauritius, Rodriguez and Reunion Islands) had been driven to extinction by 1795 whilst the Madagascar-Seychelles genus Dipsochelys still survives. This genus was found on Madagascar, the Comoros, Glorieuse, the Aldabra group (cnsisting of Aldabra, Assumption, Astove and Cosmoledo Islands), Farquhar and the Seychelles group of islands. The only surviving wild population is on Aldabra (the species is known variously as Dipsochelys dussumiieri, Dipsochelys elephantina or Geochelone gigantea).

 

Evolution of Dipsochelys Dussumiieri (aka the Aldabra Giant Toroise)

  In the past the evolutionary history of these species has remained speculative. The main thoughts are that there are two alternative views; either that the genus evolved on Madagascar and colonised all the other islands from there or that it evolved in Seychelles and colonised Madagascar, which then provided the source for all other populations. Both these scenarios have Madagascar as the source for the Aldabran population due to the proximity of these islands and the fact that Aldabra has been colonised by giant tortoises on at least three occasions (138, 125 and 50 thousand years ago). It would seem probable that repeat colonisation would require a close source population, which Madagascar would provide. There is a major problem with this however, as all the fossil remains from Aldabra are identifiable as D. dussumiieri or a very closely related form, while the Madagascan species were both very distinctive and different. Thus colonisation from Madagascar does not fit with the available evidence, which leaves a suggested alternative explanation, more probable.

  The Madagascan, Seychelles and Aldabran species are all well known, while remains found from the nearby Islands of Comoros and Glorieuse are too fragmentary to be identifiable beyond the generic “Dipsochelys species.” The important points in this evolutionary scenario are that the Madagascan species form a group of their own, the Aldabran species is closely related to a Seychelles species and both Madagascan and Aldabran species have evolved from ancestors that probably inhabited Seychelles.

  This scenario, that they originated from the Seychelles, agrees with the known palaeobiogeography and the estimated dates of extinction of the different populations but the repeated colonisation of Aldabra from Seychelles does seem unlikely. As all the low lying islands between the granitic Seychelles and Aldabra would have been submerged during the periods when giant tortoises colonised Aldabra, colonists would have had to float over 1000km of open ocean. This is possible and appears to have occurred in many animal and plant species but as a repeat event it seems unlikely to say the least.

  Alternately the less well known, extinct, populations may provide an explanation here. Glorieuse is also low lying and would not provide a source population for any colonisation events but the nearby Comoros would have been raised above sea level throughout this period. Their giant tortoises were presumably also of Seychelles origin and may have been very closely related to the first Aldabran colonists as they lie within the same marine currents. These islands are the closest land to Aldabra and with the direction of marine currents would provide an even better source for potential colonists. It can be speculated that all the islands received their first colonists from Seychelles originally, these diverged into the three main southern species - D. abrupta, D. grandidieri and D. dussumiieri, the latter possibly with slightly different forms on Aldabra and the Comoros. Sea level rises subsequently eliminated the Aldabran population 138,000 years ago, the re-emergence of the Atoll allowed recolonisation from the Comoros 125,000 years ago, followed by repeated inundation, extinction and recolonisation 100,000 and 80,000 years ago. This explains how the same form of giant tortoise could colonise Aldabra whilst appearing to be endemic (naturally restricted) to that Atoll and other lower islands nearby. This scenario predicts that when further sub fossil material is found in the Comoros it will prove to be very close to and probably indistinguishable from D. dussumiieri.

  The wider implication of this complex pattern of recolonisation is to note the surprisingly high frequency of recolonisation events. We know that these happened at least three times in the last 150,000 years. Each colonisation could have been achieved by a single gravid female landing on the Atoll. Assuming that there is no significant difference in the probability of males and females being washed out to sea and onto Aldabra this would imply that at least 6 tortoises landed on the Atoll during those 150,000 years. This represents approximately 1 every 1000 generations. This is a minimum estimate as immigration to established populations would not be detectable. However this does make the point that immigration was likely to have been an important contribution to the Aldabran giant tortoise population. Potential sources of immigrants were Seychelles, Madagascar, Comoros and the nearby low lying islands (Assumption, Astove, Cosmoledo and Farquhar) these last two would have been the most likely sources.

Recent History

  All Giant Tortoise populations have declined following contact with humans and in the last 1500 years and a number of them have gone extinct altogether. In the Seychelles there were said to be less than 8,000 animals there in 1787 after 13,000 had been removed, with at least 10,000 of them exported to Mauritius alone by the end if that year. Similar numbers had been exported to India and Africa.

  Around 1810 the Giant Tortoises were practically extinct in the Seychelles and the plunderers had moved on to Aldabra by 1822. The wild population on the Seychelles now stands around a few hundred animals, a pitiful fraction of the thousands that used to live there. On Aldabra densities can reach over 50 per hectare.

  Thanks to increase whaling activity in the area from 1823 Aldabra tortoises were regularly exported to the Seychelles, there was one voyage in 1826 who took on board 2400 tortoises. By 1892 the population on Aldabra had also plummeted to just 1000 animals. It was so drastic that only 13 tortoises were exported in the ten years before the turn of that century, presumably because more could not be located and moved over the inhospitable territory.

  Since that time the population seems to have steadily recovered and by 1925 large numbers were reported to be living on the Atoll. With such a reduction in the animals living there it means a severe narrowing of the genetic diversity of the tortoises, however this does not appear to be having any significant harmful effects on the resident population.

  With the previous recolonisation events of the past they must have gone through similar situation, however in the past animals immigrated to the islands from elsewhere, at least one tortoise per thousand generations but that is not happening now. The Aldabra population now lives in complete isolation, so if new genetic diversity is to be added it may be necessary for man to intervene and specifically transfer animals to the Atoll to prevent complications. With so many of the neighbouring islands populations being extinct and so many of the tortoises being taken to Mauritius where the breeding parks now reside, it may be unavoidable that the effects of inbreeding cannot be avoided. As so many of the remaining animals in the area will be related in some form. It may be necessary to reintroduced populations offspring of some of the long-term captive Aldabran tortoises elsewhere around the world.

 

More information on this subject can be found in EVOLUTION AND HISTORY OF THE GIANT TORTOISES OF THE ALDABRA ISLAND GROUP

by  J. GERLACH & K.L. CANNING

 

 

How Long Has Aldabra Atoll Been Around, Compared To The Galapagos Islands?

  The Galapagos Islands were formed, 3 million years ago, off the west coast of South America, and 1 to 2 million years ago the Islands were colonised by the first tortoises. It is thought that the tortoises began as normal sized and then grew and developed into giants to fill the niche, as there was plenty of food available. However, this is not certain because at the time there were at least 36 species of giant tortoise worldwide, many of which have gone extinct since, so it is possible they made it there as giants. It is probable that the initial inhabitants of the Islands are not the direct ancestors of the current occupants. Like Aldabra, the Galapagos Islands would probably have been recolonised several times over the millennia. There have been at least 20 ice ages since Galapagos was first colonised and some of those would have caused extinction events.

  Galapagos was first discovered by Europeans in 1535 and first appeared on a map in 1570 when Spanish explorers claimed it.

  Although it was 20 million years ago that Aldabra first rose from the seabed as a volcano, it later became separated from its magma source. So, it went extinct and remained a low Atoll because it could not grow further to become a substantial Island. It only finally breached the surface of the sea during an ice age when the ice caps at the poles were storing all of the water, causing sea levels to drop by 150 metres or more. This revealed Aldabra to be a high sided island surrounded by steep cliffs. Sea fluctuations over the years have revealed and covered it, at various times. These island submergences have caused tortoise populations on the islands to become both extinct and then be repopulated in the future, without human intervention.

  It is only around 140,000 years ago that tortoises began to colonise the Atoll, compared the the 1 to 2 million years that tortoises have been on the Galapagos Islands,

  The Arabs first discovered Aldabra in 916 AD, with it first appearing on a Portuguese map in 1509. Aldabra was seized by the French on their first recorded visit in 1742 but in 1811 it became a British Dependency. In 1979 it became part of the Seychelles Island Foundation.

 

How Long Has Aldabra Been Populated By Giant Tortoises?

   138,000 years ago is the first known time tortoises colonised the Aldabra group of islands, travelling from the Seychelles Islands, and not Madagascar, This is known from carbon dating shells of dead animals found on the Aldabra Atoll. Unfortunately, they were wiped out by another ice age and the resulting weather fluctuations.

   11,000 years later tortoises resiliently recolonised Aldabra but the melting of the Greenland ice sheet caused seas to rise and Aldabra was fully submerged for the final time. It took 20,000 years for the Atoll to once more become a high island and it has fortunately remained above sea level ever since. Scientist think that Aldabra was recolonised at this point by one gravid female (pregnant with fertile eggs when she made the sea crossing) from nearby Comoros Island.

  The super eruption of The Toba Volcano 80,000 years ago, once again made Aldabra tortoises extinct and had such an environmental impact that it lowered the human population to around just 15,000 people worldwide.

  50,000 years ago they once again recolonised, this time from Cosmoledo and Farqhar, only to perish again in another ice age beginning 12,800 years ago and lasting almost 1500 years. The ice caps melting around 11,000 years ago once more made sea levels rise but they did not submerge Aldabra and they were about what they are today.

   Despite large numbers of tortoises living on Aldabra, over the years, fossils are rare and fragmented. The dead bodies will be picked over by the creatures on the Atoll , including the other tortoises, as a valuable source of sustenance, including the calcium in the shell.

  Scientists have analysed the Mitochondrial DNA, at 3 locations on 2 major Islands of Aldabra and it shows that again, a single gravid female began this population at some point since the sea levels dropped and there have been little if further landings that have since influenced the Aldabra tortoise genetics since.

  It was only 5000 years ago that the rim of the Aldabra volcano was breached and the tidal flooding and erosion created the islands, and tidal lagoon, that we see today.

  It is a hostile Island and it was not until 1888 that the first settlement finally built on Ile Magnan. In 1892 it was reported that there were just 1000 tortoises left on Aldabra. The good news is that by 1925 the population had noticeably begun recovering and large numbers were seen.

  In 1971 a research station was opened on Aldabra and real efforts were made to eradicate, rats, cats and goats, that would feed on the eggs, kill the youngsters, and eat the foliage. It has been a long term process and took until 2012 to get rid of the last goats, after 25 years of trying. Visitors are strictly limited, to just the scientists who work there, to ensure the area remains as natural as possible.

  Such was the tortoises successful recovery, that between 1978 and 1982 there was a large scale trans relocation of 250 tortoises from Aldabra to Curieuse Island to repopulate it.

  Now there is around 100,000 to 150,000 tortoises, of varying ages, on Aldabra Atoll. There have also, recently, been a number of other translocations of captive bred animals, that were hatched in the conservation parks on Mauritius. These youngsters were sent to other nearby Islands, that once had their own, now extinct, colonies of Giant tortoises, to help control the biodiversity of those islands, because they are much more effective than using man and machinery.

 

 

What Is The Climate Like On Aldabra?

   The Seychelles area is tropical, with fairly unvarying temperatures of 24-30 degrees Celsius. The climate on Aldabra is a semi dry, tropical hot climate, with distinct rainy and dry seasons. On Aldabra Atoll the average temperature is 24 to 28 degrees Celsius but it can get up to over 36, in the shade, at mid day.

   They do not have four seasons like the UK, instead they have a Rainy season which is November to April, and is the hotter time of the year, with variable winds, Christmas day is around 31c. Dry season is the other six months, May to October, and it is cooler at around 22c. During rainy season temperatures can be up as high as 42 to 43 degrees Celsius, making it hot and steamy, and ever waterhole available is gladly used for cooling. The heat is oppressive, almost suffocating,

   Aldabra can be windy. Outside of the monsoon season, South Eastern trade winds blow rest of the year, which is drier, causing less rain to fall. Occasionally they are affected by cyclones in the area, which could be a disaster for the tortoises, if tree shade is uprooted, leaving them more exposed to the sun. wind can be fierce and constant along the coast with some gusts reaching 30 knots or 55 kmh.

   Being an island in the middle of the sea, the humidity level is always high and it is very hot and humid near the coast where eggs are laid, to naturally give them the incubation and humidity temperatures needed for the babies to grow. The population density of the Aldabra tortoises on the Atoll is controlled naturally by the amount of available food and water. Available to them. This both affects the potential breeding parents natural survival levels, and how healthy the females are to be able to breed, and how large a clutch of eggs it is physically viable for them to produce that year.

 

How Much Rain Do They Get On Aldabra?

   Aldabra has a wet season and a dry season. The wet season is between November and April, and it brings irregular intervals of rain. Precipitation in the area is influenced by the North Western monsoon winds, which brings heaviest rainfall, and sometimes heavy thunderstorms. The average rainfall is about 1000mm per year but it varies between years, it can range from 2880- 3550 mm.

   In a very wet year, the area around Madagascar can get 400mm of rain, every month, in the wet season, and this makes thick glutinous mud, in which the tortoises get stuck.

   In the past, scientists identified, that in the 1970s, the tortoises on Aldabra Atoll had about 2 months per year, without access to drinking water. Whereas now, it is more like 6 months of the year, as they experience reduced rainfall patterns, which are driven by Indian Ocean sea surface temperatures increasing. More commonly known as the El Nino Effect. These longer times of drought could lead to huge habitat changes, like the loss of the important Tortoise Turf, which would severely impact the tortoises health, as it is a major part, of some, of the island tortoises food diet.

   Water for the humans living there is also scarce, apparently, supply ships bring many bottles of beer to help with hydration! Scientists and support staff use seawater desalination units to filter collected rainwater for their daily needs. A Solar panel osmosis unit is designed to turn seawater into drinking water. Washing and bathing is done in the sea.

 

Do A Lot Of People Have Access To Aldabra Atoll?

   The population on Aldabra is strictly limited to scientist and researchers studying the animals and plants found on Aldabra, many of which are exclusive to this Atoll. Also present are, usually, 8 to 10 essential, Seychelles Island Foundation, support staff, who manage the island. There are a handful of low buildings clustered around the lighthouse, to provide accommodation for those, in the team, who need to stay. There are also a couple of Seychelles Special Forces soldiers stationed there, to help protect the island from pirates and other unwanted intruders.

   A low number of tourist groups are allowed to visit during the year, to raise money for the upkeep of the island but these people have to stay on their boat that brought them there, and rarely get chance to stay on the island itself, only if there was free space in the scientists accommodation.

   Aldabra is about 1000 miles from the Seychelles main Island of Mahe and is governed from there but it is the Seychelles Island Foundation who are in charge of the day to day running of the small scientific community.

   Maritime maps say not to approach within 40km radius, around the Atoll, or neighbouring Assumption Island but more charter skippers are venturing closer to the island, even though they know the islands are protected, because that is what their wealthy clients want.

   The team of protectors on Aldabra enforce the most rigorous bio security protocols in the Indian Ocean, to any visitors who come onto the Atoll. They will pick out the tiniest seeds with tweezers and go through things twice if they deem it necessary, to avoid invasive species, seeds and pathogens from being inadvertently brought ashore. All equipment to be taken ashore must be thoroughly cleaned of dust, sand and soil. It is easier to prevent an infestation than to try of eradicate it, once it has taken hold.

   Resupply ships only go to Aldabra twice a year, so it is almost impossible to evacuate everyone from the island in case of emergency.

   Aldabra has previously been protected from humans because of its inaccessibility. However, that is being threatened now, as more people are moving into the area. With the major development happening on nearby Assumption Island, to build an exclusive group of accommodation for the Qatar Royal Family and their rich friends. The small scientific community are worried what threats and impact this population expansion will pose to Aldabras idyllic and untouched world.

   It is not just the tortoises that are threatened. The success of the breeding of the Green Turtle and other rare animals, birds, insects, invertebrates, and habitat will also be under threat and it could impact Aldabras residents really hard. Maybe these rich middle eastern royalty, and their rich friends, will put their money were their mouth is, and help protect the area, to keep it as natural as possible, for generations to come.

 

Does Aldabra Really Look Like The Pictures You See On The Internet?

   The Seychelles is a region that relies heavily on tourism for its income, and giant Aldabra Tortoises are one of their attractions, so of course they are going to want to share their best image possible, with the public, to attract visitors to the area. Places like the Seychelles archipelagos conjure up images of perfect idylls. All of the pictures you see on the internet show a beautiful, clear, turquoise lagoon, with green vegetation around it. Fluffy white clouds float over clean, clear, sand and all bathed in lovely warm sunshine. A quiet perfect picture of paradise, to inspire anyone to want to get away from it all.

   The reality is different, Aldabra, and its inhabitants are at severe risk of what humans are doing to the planet. Probably one of the more important issues that is affecting them, more than the usual climate change of sea rising and temperature increases, is plastic pollution.

   Pollution clutter is creeping further and further inland, gradually covering the pristine coral white sand with washed up rubbish. Pictures always show the idyll but pollution is becoming a major threat to the species who live on Aldabra Especially the Green Sea Turtle who come ashore specifically to lay their eggs on the beach and have to clamber over an obstacle course of rubbish to even get there. Other animals risk eating it or becoming stuck in it, potentially affecting the whole range of species.

   Aldabra Atoll is surrounded by open sea, for nearly as far as you can see, it is nearly 30 miles to its closest neighbouring island, which is sparsely populated. 285 miles from Madagascar and 427 miles from Tanzania on the east coast of Africa. And there are no more than 25 scientists, researchers and support staff living on there at any one time., so it is hardly a bustling metropolis.

   However, in 2023 an estimated 513 tons of plastic was polluting Aldabra. One researcher working there, noted that in 10 kilometres alone, on the South Western edge of Grand Terre there were 1700 plastic buoys stranded on the shore.

   This plastic comes in all forms, from the ships buoys, plastic bottles both large and small, to more personal items like flip flops. Most of it floats on the surface and then is washed ashore by the currents that control the seas in the area. Netting and restraints are particularly dangerous as the turtles get caught up in it, when they come to the surface to breathe and it can kill them, either tightening around limbs and neck or getting it caught up on something else, causing them to drown. This is all without adding in the factor of plastic microbes that are involuntarily ingested by all of the animals in the food chain.

 

The tortoises may live 100, maybe 250 years but plastic can still be there in 1000 years. What is in the seas now, may still be affecting the tortoises and the animals of Aldabra in 5 to 10 tortoise generations time!

 

   Most people do not realise how bad this problem is, you conscientiously put your rubbish into your bin for collection and safe disposal by your local council. However, many times, your sorted rubbish is actually shipped all over the world for final disposal.

   We, the public, need to put more pressure on manufacturers to alter their packaging to something more sustainable. Metal cans and tins, or glass bottles and trays can be recycled time and time again but most plastic is single use and then they you can't do anything else with it, that bottle will take hundreds of years to decompose. Layers of packaging could be drastically reduced, or alternately putting it in a paper bag instead, or metal trays, which can be recycled and growing trees is also good for the environment, in several ways.

   If you are anything like us, when you look in your general waste bin, you will see that most of it is from plastic packaging. Unfortunately, it is not something we can conscientiously use less of ourselves, you are at the whim of what the manufacturers choose to use to wrap things. Why can't fruit, veg, bread or something with a short shelf life, be wrapped in the alternative biodegradable plastic? Or, even better, paper that can be recycled. Why does every item you buy have to have its own unnecessary plastic bag, when 95% of them do not need one? Or when you order multiple items on the internet, you find each item is in a plastic bag, and then each group of items is in another bag before the whole order is wrapped in a third bag, it is all so unnecessary,

It is only public pressure that is going to get the packaging industry to change. It is a world wide problem and for it to be affecting somewhere so isolated as the Aldabra Atoll it just proves how bad the situation has become.

 

Most unexpected question ever been asked at a show

  One day, we were at a show, with the tortoises, and one very interested young lad asked me an unusual question, which has always stuck in my mind: -

How Many Plane Rides Does It Take To Get To Aldabra?

  I will be honest and say I did not have a clue, so guessed at two. Well, I was right - It turns out that you hop on a plane from either London Gatwick, London Heathrow, Birmingham, Edinburgh, Glasgow or Manchester with the destination of Mahe Island in the Seychelles.

  From Mahe you then need to Charter a flight to Assumption, which is another Island in the Aldabra Group, and is the closest place with an airfield, it is about 28 miles from Aldabra itself. As Aldabra does not have an airport, or Helipad, you would need to charter a boat for the last 45km to get you there, it should take about half a day, subject to weather conditions. The boat would also be your sleeping accommodation for your time in the area, as there is no accommodation on the Island either.

  Assumption Island flights have no schedule, so you must receive information on chartering a flight directly from Islands Development Company (IDC).

  If travelling directly from Mahe to Aldabra, guests can rent or bring their own boat, if suitable for the waters. Due to the distance, which is about 1000km, across this section of the Indian Ocean, it often requires several days to travel from Mahé. The Seychelles Tourist Board can provide complete information on the commercial ships travelling to Aldabra (STB).

  You or your hire company will need to apply for permission to provide the necessary service, which includes an armed security detail, due to the current activities of pirates operating off the coast of East Africa. 

  When making any boat based travel arrangements in Seychelles waters, it is advised that you to get the most recent travel advice, on the piracy situation, from the British Embassy or high commission. (Or the Embassy of your own country, if different)

  You also have to contact the Seychelles Islands Foundation (SIF) to get permission to go to Aldabra, so be sure to plan this trip as far in advance as possible, it is not an easy, or cheap, place to get to.

 

  To that memorable young man, we hope that you manage to get your trip to Aldabra, one day.

 

Can I Really Visit Aldabra?

  Access to Aldabra itself is very limited, mainly restricted to the scientists working there and specially invited guests, only a few hundred people are allowed to visit each year. Strict bio security is implemented to prevent invasive non native species or illnesses going ashore. There is no tourist accommodation there, no helipad or jetty and only small boats are able to get through the surrounding coral reef. All visitors have to stay on board the boat, that brought them, overnight.

 Luxury two week cruises are available around that area, including Aldabra, with Ponant.com but they are expensive at around 7k per person. (we have no connection with this company and we are not endorsing it, unless they want to give us a discounted ticket!!)

  There is a big problem with piracy in the area, and the clientèle of luxury cruises can be a target, so, you must use a registered company and follow their advice, to ensure that you are as safe as possible. The COVID pandemic also hit the region hard as it relies on tourism for its income.

  Most tourists fly into the Seychelles to Mahe, you can get a direct flight from the UK, or arrive on a cruise ship. There are several places on Mahe where you can see the giants: Victoria Botanical Gardens, Cap Lazare Nature Reserve. Other places are The Jardin Du Roi Spice Garden, or you can meet Maka and Taka, the Aldabra Giants, at La Plain St Andre in Au Cap.

  Alternatively you can join a tour to some of the neighbouring islands such as:

• Moyenne Island, is part of the St Anne Marine National Park and is North East of Mahe. It is open to visitors and you can see over 100 Aldabra Giants roaming freely and naturally around the island.
• Curieuse Island is also a Marine National Park and has 200-300 tortoises roaming around, you will even spot them down on the beach. Some of these adult tortoises were translocated directly from Aldabra Atoll, to help repopulate this Island, between 1978-1982. They also have a tortoise nursery where the hatchlings live until 5 years old and then they are released into the wilds of the island.
• On La Digue Island there Anse Severe, in the North West area. Also La Union Estate Farm Park, which is a former coconut and vanilla plantation located to the West of La Union and, apparently, is probably the most affordable way to see the tortoises roaming around.
• Desroches is another island you can see giant tortoises. It is home to around 150 of them, many of which roam freely across the island. The island is also the location of a tortoise sanctuary where guests can learn all about the giant tortoises and the conservation challenges they face.
• Staying at the luxury, exclusive and secluded, Four Seasons Resort Seychelles, the only hotel on the island, allows you to stay and enjoy seeing their own population of Aldabras, and it is more accessible than Aldabra Atoll itself.
• Fond Ferdinand Nature Reserve on Praslin Island also allows you to see giant tortoises in their natural habitat.
• Several males living on Cousine Island are over 100 years old, these include Adam, who is at least 126 and Mr Les, discovered on Cousine and weighs 326kg and is thought to be older than Adam.  

   Aldabra tortoises roam freely on several other Seychelles islands, such as North Island, where large males Brutus, who is thought to be over 200 year old lives but there is no proof, of his age, so he is unable to claim the title from the famous Jonathan as the oldest living tortoise. Big Brutus weighs around 200kg, and along with another large male named Patrick, they free roam the island. There are currently around 80 to100 tortoises there, many of which were gifts from other islands. You can stay on North Island and explore at your leisure.

 

Maritius is also a popular destination for seeing Aldabra Tortoises in the Conservation Parks there.