Aride Island Nature Reserve stands out within the Seychelles’ archipelago for its incredible bird population, especially its land birds. But how can this claim be verified?

Nothing can prepare you for a first visit to Aride Island. It is a sensory overload similar to attending a chaotic concert where performers care little for harmony and volume. Among the cacophony, identifying each call and distinguishing between the birds, whether it’s a seabird or land bird, is almost impossible. Aride Island hosts one of the most important seabird colonies in the Indian Ocean, with around half a million birds of up to 10 species. Additionally, it is home to at least six land bird species, creating unparalleled avian density and diversity, almost unmatched in Seychelles or even globally.  Or is it?

To confirm this, Alex Koehler, a biology student from the University of Constance in Southern Germany, has made it his three-month mission to survey the land birds’ population of the island as part of his thesis for his Master’s degree. A mammoth task, as it is estimated that the island of 68 hectares (more than twice the size of Cousin Island) has over 10,000 avian land inhabitants. Out of this 10,000, the endemic Seychelles Fody (Foudia sechellarum or ‘Tok tok’ in Creole) surpasses all other species with an estimated 5 to 7 thousand individuals. Other species such as moorhens, doves and the Seychelles sunbirds (Cinnyris dussumieri or ‘Kolibri’ in Creole) are also present but in small numbers. 

Alex is, however, more excited to establish the population of the Seychelles Warbler (Acrocephalus sechellensis or ‘Pti merl de zil’ in Creole) since Aride is said to hold the most abundant population of this species, which had been introduced from Cousin in 1988.

“As an endemic species that was on the brink of extinction in Seychelles, this is a remarkable story of recovery for Seychelles, considering it can now be found on five islands,” says Alex. It is estimated that Aride now holds the largest population of this species, as previous studies have shown that, unlike other islands, on Aride they also breed throughout the year, perhaps due to good habitat quality with a high food availability.
 
“This census is essential to establish the population of each species and monitor against sudden changes,” says Alex, adding that ‘island populations are more threatened by catastrophic events, diseases and genetic impoverishment’.

While less abundant species that conquer bigger territories, like the Seychelles Blue-pigeon, can be sufficiently monitored using a broad grid of point counts that covers the whole island, species occurring in high densities are harder to estimate. Each Seychelles Warbler family inhabits an average territory of 200 m². A feasible point count grid cannot catch every single bird on the island because it is not fine-grained. Therefore, Alex will first ring as many Seychelles Warblers as possible in a restricted area to estimate the densities and get an impression of the total number of birds in that area. This knowledge helps to put the point counts into perspective and ensures a more robust estimate for the whole island.

Counting birds seems simple enough, but this survey is not without difficulties. Dense and high vegetation in certain areas of the island may limit visibility and thus decrease the detection probability. Further, the limited track system on the island poses challenges to accessing all points where the point counts are conducted.

“The steep terrain makes it difficult sometimes, and you need a good sense of orientation to not get lost,” says Alex, adding that luckily, the island is not very big and at some point, you will always reach the shores.
Using data from as far back as 2000, Alex hopes his census will assist in establishing the population trend and extract key features that have made it favourable for this species to increase abundantly on Aride.
The project will run for three months, but Alex is happy to spend time on Aride among birds and close to the ocean. ​

At just over 5 kilometers long and 1-kilometer-wide, Desroches is 39 times smaller than Mahé. It is a coralline island that forms part of the Amirantes Group of the Outer Islands. The island has been heavily altered since people arrived, with much of the native vegetation being cut down to make way for a coconut plantation. Today, Desroches is more known for its free-roaming giant tortoises and high numbers of nesting sea turtles.
 
In 2009, ICS established a conservation center on Desroches to focus on environmental rehabilitation, monitoring, and research. The goal was to educate staff and visitors alike while ensuring that Desroches Island would become a model of success through the partnership of ecotourism and conservation. After 15 years, Desroches is a demonstration of what long-standing restoration and rehabilitation work can achieve on a remote island.
 
Sharing the Island
 
For Desroches, conservation has been a collective effort, with all partners working collectively on various projects. The Desroches Foundation raises funds for conservation initiatives and monitoring, supported by Four Seasons, the Islands Development Company (IDC), and the Desroches Home Owners Association. While not everyone shares the same priorities, collaborative planning has yielded productive outcomes. All parties work hard to protect the island’s most important species, including sea turtles, tortoises, and Wedge-tailed Shearwaters.
 
Incidentally, the Wedge-tailed Shearwaters have established the largest breeding colony of the island within the hotel grounds. Therefore, ICS works closely with the Four Seasons on various aspects of the conservation of this seabird species, leading to one of the most successful recovery stories for the island. “In the 2024-2025 breeding season, over 1,500 pairs were estimated to be on the island, marking the highest number ever recorded,” says Elisabeth Wareing, the Conservation Officer on Desroches.
 
Meetings of the Desroches Foundation are held three times a year to track the progress of conservation work plans, propose and budget for projects aimed at preserving the ecosystems and species conservation, and introduce initiatives that allow visitors to engage with the island’s natural environment. One such initiative is the Tortoise Adoption Program, which has been running since 2021 and has helped raise funds for ongoing conservation efforts. Visitors can visit the tortoise sanctuary regularly and interact with over 150 juveniles, which are cared for until they reach 9 kilograms when they are released to roam freely on the island.
 
“These tortoises play an essential role in restoring the island to its natural state by spreading seeds and creating diverse habitats. They also serve as a link between visitors and the island’s biodiversity. Guests can adopt a giant tortoise with ICS, keeping a connection to their adopted tortoise even after leaving the island, all while supporting our conservation work,” explains James Wareing, the Assistant Conservation Officer at ICS on Desroches.
 
Conservation Success
 
The restoration and rehabilitation efforts on Desroches have started to show remarkable results in the number of birds that had previously been driven away by human activity and have now returned and begun to breed on the island.
 
One such example is the Fairy Terns, which had previously only been spotted sporadically and have now established a breeding colony of approximately 50 pairs on the island. Similarly, other species, such as White-tailed Tropicbirds and Madagascar turtle doves, that were absent when ICS first established the conservation center in 2009 have also returned and begun breeding on Desroches.
 
Throughout the 15 years, ICS have unveiled various unknown aspects of Desroches and the surrounding Indian Ocean. For example, exciting marine species have washed up on the shores like the False Killer Whale, the Ginkgo-toothed beaked whale, and the Sperm Whale. Another exciting discovery is that the lagoon provides a haven for various marine species, especially Hawksbill and Green sea turtles that feed on the sponges, algae, soft corals and seagrass.
 
Every year, projects are initiated to meet environmental challenges. One such project is the introduction of reef balls along the coast to mitigate against coastal erosion and provide a habitat for marine species. ICS is also actively learning and exploring other aspects of the island’s ecosystem. A comprehensive inventory of all species found on the island is one example of such a project that has recently been approved by all partners. This has already led to records of insect species that had never previously been recorded in Seychelles and the discovery of a species of crab previously only known from the Inner islands.
 
This is an exciting time for Desroches and a far cry from the situation in 2009, when ICS began its conservation efforts on the island. “Back then, there was a small lodge on the southwest of the island, catering to visitors and a handful of IDC staff and two ICS staff. The island was managed by the IDC, with each group going about its own business,” says James. “At that time, the only native bird consistently breeding on the island was the Wedge-tailed Shearwater.”
 
Fifteen years later, Desroches has much to boast about, thanks to the dedicated efforts of conservationists, researchers, and donors. The island now stands as a shining example of sustainable development and a testament to the success of ICS’s long-term commitment to conservation.

Upon arriving on Ile Plate, what strikes you is not only the flat sand cays exposed at low tide and the far-reaching lagoon outlined by a foamy white barrier where the ocean meets the coral reef, but also the lush green vegetation that conceals all human habitation.

Upon closer inspection, one is surprised to note that apart from coconut trees, the greenery is mostly attributed to Castor oil (Ricinus communis) or ‘Tantan’ in Creole. This introduced species is believed to occupy an area of 5,000 square meters, which is roughly the size of a football pitch. It is considered one of the most dominant invasive species on Ile Plate, an island slightly bigger than Ile Moyenne. What is worrying to conservationists is that the plant is now widespread, and there are no indications that it is slowing down.

This has prompted the Island Conservation Society (ICS) to implement a vigorous eradication program to contain this species, which, as on other islands of Seychelles, was introduced and cultivated for its medicinal properties and is now escaping into the wild.

“We cleared this area as part of our first project on the island. And look how it is now! They’ve all grown back,” says Diary Rakotondrazara, the Conservation Officer of ICS, as she points to a growing patch of thick Castor oil. So thriving is this species on Ile Plate that a tree measuring 5.10 meters - the height of a two-storey building - has gone down as the tallest ever recorded.   

“The best way to eradicate Castor oil without disrupting the environment is to do it manually,” says Rakotondrazara, adding that this necessitates uprooting each plant one after the other. As part of their weekly routine, the team remove Castor oil plants regularly, with an ambitious target of clearing a 5-meter square area per week. “In one month, we can remove as many as 340 plants from fruiting trees to different sizes,” she adds.  With a flowering season that spans throughout the year, the task is harder than the team initially thought it would be.

So far, castor oil is found almost everywhere, but they are most abundant in the northwest to southwest of the island. Since ancient times, the medicinal properties of the Castor oil plant have been documented, and to this day, in several countries, different parts of the plant are still used for such purposes. The seeds, for example, are known to purge worms whilst the leaves can be crushed to make ointment to cure wounds. On the other hand, Castor oil is also very toxic if ingested in large quantities, and it is also used as a natural insecticide in agriculture. But when left in the wild as on Ile Plate, this species can also become very invasive.

“The seeds can stay in the soil for a very long time and re-sprout again even after a short drizzle,” says Rakotondrazara. “We have noticed that several areas which have been cleared have already been recolonized by the plants. In addition, many trees have fruits, and these are easily dispersed by birds and people but also by wind to other areas.” As part of their strategy, the team always remove the seeds first before uprooting the plants. An astounding 3 kilograms of Castor oil seeds have been collected and disposed of by ICS since their arrival on the island late last year.  

These past 6 months have been a learning curve for the team as they learnt to tackle this species and assist in restoring the biodiversity of the island. The project is also of great interest to other partners on the island, as Castor oil plants also harbour a species of caterpillars from the genus Euproctis - a yellowish-black caterpillar with stinging hairs or “hairy caterpillars,” locally referred to as “Senir plim,” which can cause incessant itching. Spraying these hairy caterpillars is not encouraged as this could also hurt insects and other biodiversity of the island, including the abundant diadem butterflies.

Such projects are also vital for other restoration projects that ICS wishes to implement on Ile Plate. Another plant species on ICS’s radar is the Coco grass (Cyperus rotundus), or “Lerb Zonyon” in Creole which is an indigenous plant that has also grown in abundance on the island. This plant species is referred to as one of the most invasive weeds in the world and is widespread on several continents. Similar to Castor oil, Coco grass is also a conservationist’s nightmare, as it is difficult to control, since its tubers can grow up to 8 inches below the ground surface, and it is also highly resistant to herbicides. 
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ICS is dedicated to safeguarding the biodiversity of Ile Plate, one of the smallest islands under its care, with a strong focus on preserving its terrestrial ecosystem. New bird species, such as the Brown Noddy (Anous stolidus), Lesser Noddy (A.tenuirostris), Wedge-tailed Shearwater (Ardenna pacifica) and the Red-tailed Tropicbird (Phaethon rubricauda), have already shown interest in recolonising the island. Improving the island's plant life is expected to further increase the likelihood of other species establishing themselves on this small yet significant island, located just a few kilometers from Mahé and at the edge of the Outer Islands group.

The Island Conservation Society (ICS) has started to map Seychelles’ fourth-largest known seagrass meadows located around Ile Plate, a vital carbon store and mitigation mechanism against climate change.

Seagrass have evolved from land plants and, like terrestrial plants, have veins, roots and leaves. As true plants growing on the ocean floor or seabed, they also have a flowering season and can reproduce underwater. They form meadows on the ocean floor, which provide food and shelter to different marine life, from sea turtles to crabs. Yet, not much is known about these green barriers that, similar to mangroves, help to keep our oceans clean by removing harmful algae and stabilising the sand. More importantly, seagrass creates a highly efficient carbon sink by storing significant amounts of carbon in their sediments and biomass and playing a crucial role in global carbon cycling and climate change mitigation.  

In 2020, a project to map the seagrass meadows in Seychelles was launched. The Seychelles Seagrass Mapping and Carbon Assessment Project revealed that there are 1,599 square kilometers of seagrass in the Seychelles Exclusive Economic Zone (EEZ). Surprisingly, it also revealed that Ile Plate accounts for 7.9% of this total area, ranking it as the fourth largest area where seagrass was found in Seychelles, surpassing other areas renowned for their high biodiversity, such as Aldabra Atoll, Farquhar Atoll and Cosmoledo Atoll. Only Providence (14.4%), Mahé Rim (24.5%), and Amirantes Bank (34.1%) outranked Ile Plate in the density of seagrass found through this project. Despite the significance of this project, several questions remain about the areas which had been mapped, for example, what the meadows were made of, how widespread they were and what habitat they were supporting.   

Looking at the lagoon from the air or even from the beach, “we could see these large expansive meadows – in some areas all you can see is seagrass. You can take only a few steps towards the ocean and end up knee-deep in seagrass here,” says Diary Rakotondrazara, who is the Conservation Officer of ICS on Ile Plate.
To better understand this habitat, the team has initiated an in-depth review of seagrass meadows around the lagoon. At low tide, the meadows around Ile Plate are easily accessible, and the team does not have to snorkel to view underwater environments.

“We use a 50-meter line across an area which is checked at every 5-meter interval. At each interval, we observe an area of one meter square where we identify the species we found, the amount of seagrass there is, the height of the seagrass and if there are any algae. We then take pictures and record the GPS coordinates of the area first at the beginning and then at the end.”

By analysing all this information, the team will be able to confirm the density and distribution of the island’s seagrass. There are at least 72 known species of seagrass globally, 12 of which are found in Seychelles.
So far, the team has identified at least three seagrass species around the island, but their density varies. The most common species of seagrass found in the lagoon are Thalassodendron ciliatum, known as “Gomon zerb levantay” or Fan seagrass and Thalassia hemprichii, known as “Gomon torti” or “Gomon zerb torti” or Turtle seagrass. In addition, the team has also identified several patches of Syringodium filiforme, known as “Gomon zerb sed” or “Gomon zerb spageti” in Creole or Casuarina seagrass or Spaghetti seagrass. These are mostly located a few meters from the beach and, according to the initial mapping exercise, are not common in the Outer Islands, such as Ile Plate.

Seagrass “was always a target of our conservation strategy on Ile Plate,” says Rakotondrazara, adding that unlike the other five islands where ICS has a conservation center, the role of seagrass towards the thriving marine life around the island could not be overlooked. 

“Thanks to these meadows, we can now confirm that Ile Plate is a nursery and foraging area for juvenile sea turtles and that they are actively using the island for nesting throughout the year. We can also confirm that the island is a major hub for elasmobranchs, which is another major milestone for conservation of the island.”

As helpful as seagrass is to the marine ecosystem, ICS is also enlisting the help of its partners on the island to help improve their understanding and find ways to protect these seagrass meadows against marine activities such as anchoring and snorkeling. Visitors are already being sensitised about seagrass through informational displays that provide more information about the different seagrasses they may encounter during their stay on the island.

“We’re just beginning to realise how important the seagrass meadows are,” Rakotondrazara says. “As such, unlike other places in the world where seagrass is underrated or overlooked, we want to make this a priority for conservation on Ile Plate.”
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Whilst the survey will be an extensive exercise and part of the regular monthly conservation activities by ICS on Ile Plate, it will also build on the initial Seychelles Seagrass Mapping and Carbon Assessment Project. Furthermore, the details about what’s in the meadows will help to inform future projects around Ile Plate and feed into Seychelles’ national database of information on seagrass. 

My name is Cai, and I’m from Cambridge, UK. I studied Natural Science at university and have had the privilege of volunteering on Aride Island for the past 4 months. This article is a glimpse into the wonderful life I have discovered here in the Seychelles.

Life on Aride is surprisingly difficult to describe. Before I came here, I expected that nature would be at my doorstep, but I didn’t quite realise that it would also be in my hair and between my toes. My sleep schedule is decided by shearwaters, my kitchen overrun by skinks and my free time controlled by turtles. Every night I fall asleep to the sound of mosquitos in my ear and wake up to the insistent call of fodys at my door. I wash my clothes and hang them outside my window to dry, however the constant monsoon weather means that they remain as wet as the day I put them out.

To those who have never been to Aride, these may sound like complaints, but strangely, they are some of the many reasons I find it so hard to leave. There are few places in the world that feel quite so alive. Wherever you look there are creatures staring curiously back at you. Whether it's the white tail chick hiding beneath a boulder, the tortoises demanding a neck scratch or the charming magpie robin following you dutifully through the forest - it is apparent that while we may be there to monitor the wildlife, more times than not, we are the ones being monitored by them.

Coming from the UK, I had experienced island life before. Of course in my case, I had shared the island with 65 million other people as opposed to the 11 neighbours I currently have. My old layers of evening jumpers have been replaced by layers of suncream, and my salt and pepper spice drawer has exploded with the colours of turmeric and chilli. As you might expect, I have adapted enthusiastically to warm weather and tasty food, although life here is not always stress-free.

Following the plane ride, ferry trip and motorboat journey it took to get me here, the extreme disconnect with my life back home became evermore apparent. I found myself waking up with new bites and bruises every single night as the forces of the island took their toll on my soft English feet. I would try to call my family for a bit of comfort, but the broken phone signal would leave me feeling even further away. However, these challenges were quickly forgotten as I began to know the island. The warmth of the Aride community made me realise that while I might be far from home, I had found a second home right here. As was explained to me after a particularly unsuccessful fishing trip, my family might be far away, but the islanders were happy to step in and take their place in the meantime.

If there is one thing I have learnt from my time here, it is that Seychelles culture is best explored through food. Through island barbecues outside Steve’s house and fresh fried fish at Jean Claude and Laurette’s, I quickly learned that the colourful, warm culture I experienced with the islanders was perfectly mirrored by the food they eat. Having enjoyed a selection of especially tasty meals, I found myself eager to absorb as much of their culture as possible. As it turned out, the Secyhellois’ desire to teach and share matched perfectly with my own desire to learn and eat. I found myself being generously welcomed aboard the fishing boat and I learnt how to detangle my line and even catch an occasional fish for dinner. Mealtimes became the perfect excuse for weekly social gatherings. It was around these barbecues that we would spend hours discussing the details of our past lives while enjoying a seemingly endless supply of freshly grilled fish.

Around the world, Aride is known for its pristine white beaches and stunning variety of seabirds. While this is undoubtedly true, what made it so special to me were the people who inhabit it. I would like to take this chance to thank everyone on Aride for making this small granitic island so extraordinary.

In 1787 Jean-Baptiste Malavois provided the first written description of Aride as “…just a pile of rocks covered with some bushes.” He could not have been more wrong.

A visitor to the Seychelles recently shared a photo of a “strange-looking” marine species he had caught on a fishing trip close to Praslin. They could tell that this was no ordinary fish but rather a very peculiar-looking shark with its unusually rounded face and conical snout and a long, curvy whip-like tail almost double the length of its body. This individual was quickly recognised as the iconic Thresher shark or, more specifically, the Pelagic Thresher (Alopias pelagicus), also commonly known as “Renar” in Creole.

What the visitor and his fellow fishermen did not know was that they had caught a rare specimen of an endangered species that was once on the brink of extinction. Luckily for conservation, fearing that this was a rare species, the fishermen safely released the shark. The video of the shark being released and the photos are now photographic evidence that this species frequents the Inner Islands, providing a spark of hope for the species and the health of the ecosystems.

The Pelagic Thresher is the only one of the three species that frequent the Indian Ocean and the Pacific Ocean. The two other species, the Common Threshers (Alopias vulpinus) and the Bigeye thresher (Alopias superciliosus), are listed as ‘Vulnerable’ by the International Union for Conservation of Nature (IUCN) and are found globally. All three species are naturally docile and are, therefore, highly susceptible to being captured by humans at various scales, leading to drastic declines in their worldwide population. These listings are also based on the fact that Thresher sharks take at least 12 to 13 years to reach maturity and will have only one to two pups per breeding cycle. As solitary creatures, once they reach maturity, Threshers travel to small pockets of the world ocean, leading to reduced genetic diversity, putting the species at risk of population collapse and possible extinction.

What’s more interesting about this species is that it uses its tail fin to jump out of water, possibly as a form of communication –similar to dolphins. Recent videos have also proven an old anecdote that the long tail is used to stun its prey through a wiping or lashing movement that can kill small fish such as mackerel. Other species, such as Humpback whales and Sperm Whales, also exhibit similar fishing tactics. Imagine the strength of a fish that can grow to 4.6 meters (and even 6 meters as an adult) and at a size of more than 290 kilograms to be able to leap out of water. Beyond their agility and manoeuvering ability, Threshers are shy and non-aggressive, thus typically posing no danger to humans.
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This encounter is just another example of how vast the ocean is and truly little we do not know about the marine life that inhabits it. Only recently did a video captured a Thresher shark giving birth, but their preferred habitat, feeding habits, etc., are yet to be documented. This has not prevented the Thresher shark from being the target of sports and commercial fishing, where its fins and meat are considered a delicacy. With 37% of sharks currently being threatened with extinction, there is so much we would lose if this shark had not been released, like the inevitable fate of many others. Plus, we are now more intrigued to encounter this species in its habitat and why not enjoy the absolute awe of a such a marine creature?

The term "cuckoo" often evokes the notion of madness. It also conjures the image of the German-inspired clock with the resounding sound “cu-coo” that signals the hour. In literature, the term "cuckold" refers to a husband who has been betrayed by his wife. In contrast, William Shakespeare uses the cuckoo as a symbol of the approaching spring and fertility. Additionally, in Greek mythology, the cuckoo bird is considered sacred. Overall, all of these references highlight one of the most beautiful and intelligent birds in the world – the cuckoo.
As part of their daily monitoring of the different islands, the Island Conservation Society (ICS) staff observes different bird species and January was a particular “cuckoo” month. These birds have a wide range of habitats from forests, and deserts to wetlands. Following the end of the mating season, solitary cuckoos, like so many other migratory and vagrant birds, travel to the warmer African region for a few months to forage. Unfortunately, when they are not breeding the male cuckoos, which have very distinctive songs, rarely sing. This leaves detecting them merely up to chance or good observation skills.
The species comes from a big family which also includes the roadrunner. Their appearance and size range from 16 cm to 90 cm and from grey to brown with patches of white or even emerald green. This makes it even more fascinating to spot any of the cuckoos, which are often shy of people and like to hide in dense forests – their preferred habitat. Their downward-curving beaks are ideal for feeding on various food sources, varying from fruits to small insects, including hairy caterpillars, which most birds would avoid. Cuckoos also share the same odd toe formation as the parrots - with two toes facing forward and two backwards.
Interestingly, cuckoos are also known for their lack of parental skills. A female cuckoo lays its eggs in the nest of another bird, often discarding the owner’s egg in the process. This behaviour, known as brood parasitism, is quite extreme; the female mimics the colour of the eggs in the nest and the chick produces the begging calls of the host bird. As a result, the unsuspecting host cares for the cuckoo chick, which then typically eliminates any other chicks that are not its siblings. This fascinating yet ruthless strategy highlights the cuckoo's unique survival adaptations.
According to the International Union for the Conservation of Nature, most cuckoo species are of Least Concern. Despite this, Cuckoos are globally threatened, with big declines in breeding populations and ranges. For example, since 2021 the Common Cuckoo species has been added to the Red List in the UK Conservation Status Report to prioritise its conservation status due to a decline in its population.
Although many vagrant or migratory birds are spotted by ICS on the Outer Islands, according to the Seychelles Birds Record Committee (SBRC) all of the three cuckoos below have been spotted in the Inner Islands including on Praslin, La Digue, Bird and Denis Island in the past. There is also another species that has been seen in Seychelles, the Great Spotted Cuckoo (Clamator glandarius) which sports a remarkable patterned back.  However, this has only been seen twice, on Bird and Aldabra.

The following are three species of cuckoos spotted by ICS last month – including a ‘cuckoo’ day where all three species were spotted in one day on Desroches.

Asian Lesser Cuckoo (Cuculus poliocephalus)
As its name implies, this is a small species which is about the size of the Seychelles Bulbul and is abundant in many Asian countries where it is revered and has been immortalized through many myths and legends. For example, in Japan, it symbolizes unrequited love. At first glance, it looks very much like a Common Cuckoo, which is a more common visitor to Seychelles. However, it has a shorter bill and a more ‘cute’ appearance. The bars on their breast are also thicker than those of the Common Cuckoo. When the conservation team on Desroches saw the bird, these features are what immediately stood out to them. Lesser Cuckoos are primarily insectivores and play an important role in controlling insects such as caterpillars. However, depending on availability, they are also known to feed on fruits and seeds.

Common Cuckoo (Cuculus canorus) 
The Common cuckoo is the only member of the Cuculidae to have the ‘cu-koo, cu-koo’ calls. It is found throughout Europe, Asia and Africa. Featuring a sleek greyish body and a long tail, it is a very secretive bird, not liking to be in the open for too long. As this species can also be found in Europe, the team on Desroches were very familiar with this species. They were excited to see it as a reminder of home, and there have been at least four individuals who have visited Desroches over the last two months. This is also the most common cuckoo to be spotted throughout Seychelles, with over 80 accepted records.  

Jacobin Cuckoo (Clamator jacobinus)
This is a distinct cuckoo as it sports a crest, which it often displays when nervous. It has a black back and a white patch on its wings which makes it unmistakable. During the breeding season they have a strong and noisy note resounds like ‘pi-piu’. In India, its arrival is celebrated as an indicator of the rainy season and it is commonly referred to in poetry. The genus name for this species, Clamator, comes from the Latin for shouting. In January, a Jacobin Cuckoo was spotted on Alphonse, Ile Plate and Desroches. Surprisingly, on Desroches, the bird stayed for the whole month and the team can confirm that it lives up to its name!

When people first started to settle on the Outer Islands, they also brought with them—albeit sometimes inadvertently—invasive species such as rats. They also brought cats for company and chickens as a food source. Today, these same species are causing a rampage on the biodiversity of our islands, creating an urgent need for eradication.

Because of human activities it is common nowadays to hear a rooster crowing at dawn on several Outer Islands of the Seychelles. While this is very traditional, for conservation however, domesticated animals gone wild and pests such as rats are not necessarily ideal in these circumstances as they can have devastating effect on the biodiversity of these islands.

Alphonse has been assessing and implementing measures to protect existing biodiversity on the island against such wild animals and pests since 2007, and today we take a look at proceedings there to eradicate existing threats through the lens of the Island Conservation Society (ICS) the "guardian of the custodian" on the island.

“Whilst we get large numbers of roosting seabirds, our breeding populations have always been small with low success rate,” states Conservation Officer, Jack Coupland. Conservationists believe that this could be a result of the high incidences of predators such as cats and rats on the island. Both cats and rats are incredibly adept predators as they are known to climb up trees to take down fledglings, grappling them off their perch before forcing them to the ground and consuming them. Similarly, chickens are also considered invasive since they compete for the same source of food as small reptiles, and share the same habitat as ground-breeding species and their foraging habit disrupts the ecosystem.

In 2024, it was estimated that the main island of Alphonse had a population of around 400 chickens and over 30 cats. To curtail this, ICS and its partners on the island have for the past seven months employed a full time staff to help with the eradication efforts of both feral cats and chickens. According to Coupland, so far, the team have exterminated 21 cats and over 200 chickens on Alphonse Island. ICS is also ramping up a combination of baiting, scent marking, and specific attracting calls to successfully eliminate the remaining cats and chickens in the most humane way possible.

Already regular trapping of rats around the island using passive baiting stations has proved successful on the existing colony of Wedge-tailed shearwater, a seabird species that dig burrows underground to lay eggs. Since the introduction of active pest control on Alphonse in 2017, the population of this species have been growing exponentially. This is great news, not just for the species, but for the island as a whole, as seabirds transfer huge amounts of nutrients from the sea to land – known as the marine subsidy – that then trickles down through the ecosystem benefiting a wide range of species, including the coral reefs and reef fish.  
Eradication of cats, chickens, and rats may seem heartless but there is a much larger mission at stake for Conservationists: preventing them from traveling to other islands in the Group; namely St Francois atoll, where coconut crabs and other ground-dwelling species are in abundance. The atoll is currently one of the rare places in Seychelles which is ‘predator-free’.

Total elimination of all three species however will take time and is already proven to be very costly for Alphonse Island which has a land area of 165 hectares made up of dense coconut trees and ferns. The ongoing efforts on Alphonse are estimated to cost ICS upwards of 20,000 USD monthly and over 50,000 USD annually. However, this is a small cost compared to the long-term cumulative damages inflicted by predatory species and ICS has plans to introduce similar vigorous eradication projects on other islands. Already, Desroches Island has benefitted through a SeyCCAT-funded project, where sophisticated rat traps have been installed to protect its Shearwater colony. The devices do not need to be checked every day, automatically share the number of kills they have completed via Bluetooth to the Conservation Officer’s phone.  Coupled with this, ICS and its partners through the Islands Development Company (IDC) are actively trapping rats, and an astounding 300 rats are killed per month. However, cats and chickens remain loose on the island and their total population is still uncertain. Similarly, on Ile Plate, there is ongoing trapping of rats, but the estimated over 200 chickens and at least 20 cats are not being targeted. A short bout of two months of active shooting and baiting by ICS resulted in reducing the population of both chickens and cats by half.

The same cannot be said for bigger islands such as Farquhar Atoll which covers an area of about 17,800 hectares. A massive project would be required to eradicate cats and chickens on the Atoll. Hence, ICS and its partners are only passively baiting for rats and cats, but lacks the resources and funds to aggressively eradicate them.

The same applies to Silhouette island, the largest terrestrial National Park of Seychelles – home to the rarest and smallest bats in the world, the endemic Seychelles Sheath-tailed bats (Coleura seychellensis or Sousouri bannann) – where gains have been slow and hard-won. Cats have been seen preying on these small bats that live in caves not far from the human population. Active trappings around the roost and around the island are targeting both rats and cats which their effect on the biodiversity cannot be underestimated. 
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Through careful management, key predators are slowly being removed on several islands. ICS’ efforts to control the population of cats, rats, and chickens and eventually eradicate them completely from Alphonse is proof that this process is an arduous one.                                                 

Seychelles declared protective status for sea turtles in 1994. Despite conservation efforts to prevent exploitation and consumption, their numbers have dwindled on the Inner Islands. However, on the Outer Islands, such as Ile Plate, the sea turtle population is not just surviving – it’s thriving.
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Of the two species of sea turtles that nest in Seychelles, the Hawksbill sea turtle (Eretmochelys imbricata), listed by the International Union for the Conservation of Nature (IUCN) as critically endangered globally, has seen a remarkable recovery. In 2024, a milestone of 317 nests and over 600 hatchlings were recorded on Ile Plate alone. The Green sea turtle population on the outer islands has also flourished, with impressive nesting numbers throughout the year. Thanks to the dedicated conservation efforts of the Islands Conservation Society (ICS) and its partners, Ile Plate has become a sanctuary for these remarkable creatures, where sightings are a daily occurrence.

It’s a turtle!
​Every day at dawn, the ICS conservation team led by Diary and Saddiqua patrols the pristine beaches of Ile Plate, recording sightings and documenting sea turtle tracks. These tracks provide vital information, allowing the team to identify the species estimate the number of nesting females emerging on Ile Plate, and determine whether eggs have been laid. An unsuccessful egg-laying turtle - which could have been spooked by something or did not find the right spot to lay its egg - would probably come back that same day. After almost 6 months of doing at least 1 hour and 30 minutes -walk around Ile Plate, the excitement of spotting a female turtle nesting has not worn off. On Ile Plate, this can happen once to three times a day and sometimes at night! “We can be having lunch and suddenly someone might spot a turtle nesting. And we will be called in,’ says Diary. When a turtle is spotted nesting, the team swiftly moves into action. They wait for the turtle to complete her nest, then mark the nest with a GPS point and write on the coconut the information necessary, including the number of nests, dates and species. They also tag the turtle if it does not have a metallic tag providing a number, island and country for future identification. If the nest is at risk of being washed away by rising tides, the eggs are carefully relocated to safer ground. The highest number of eggs counted so far was 206 and the minimum was 69. A delicate operation for a team of two that can take 1 hour to 1 hour and a half!

The hypothesis
A permanent team of conservationists arrived on Ile Plate in August this year. Before then, the data on sea turtles were collected by visiting conservationists or the staff of Waldorf Astoria or Island Development Company (IDC) on the island. The increase in turtle activity and the number of new turtles tagged in 2024 confirm that Ile Plate is a critical haven for sea turtles. Many of these turtles have not been previously monitored elsewhere in Seychelles, highlighting the unique importance of the island for conservation. So far, the data of 2024, confirms previous suggestions by Conservationists in Seychelles, that Ile Plate could be an important nesting ground for the two sea turtle species. Another 12 months of monitoring by ICS will accentuate this hypothesis and provide more reliable data on both species.
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 Good news for sea turtles
​For visitors to Ile Plate, with its newly opened luxurious Waldorf Astoria hotel, seeing a sea turtle is one of the perks of being on this island. For conservationists, each sighting is a chance to create more awareness of the plight of this species that could go extinct in just a few more years. It is also an opportunity to educate others on the dangers this species faces as they navigate the high sea against pollution, constant poaching, habitat loss, etc. In addition to this, the data on Ile Plate is something for conservationists to boast about. The long-term data adds up to Seychelles’ conservation success in its efforts to protect this species. It also creates the impetus for the monitoring protocols to be duplicated in other islands where sea turtles are not as abundant. The success story of the Ile Plate offers a glimmer of hope for the global standing of both the Green turtle (Chelonia mydas) and Hawksbill (Eretomochelys imbricata) suggesting that small, protected ecosystem can help preserve species at risk of extinction.  

Yellow Crazy Ants, or YCA (Anoplolepis gracilipes), were first identified on Mahe in the 1960s and a decade later on Praslin. In 2009, they gained more notoriety as an invasive species, posing a threat to two Nature Reserve on Praslin: the UNESCO World Heritage Site, the Vallée de Mai, and Fond Peper. With their unique zigzagging movement, YCAs have an effective method of infesting areas by hitching rides with humans or any other means of transportation, allowing them to travel long distances and form super colonies with one or more queens. Additionally, this long-legged ant uses formic acid to paralyze and kill other species, regardless of their size. These characteristics render this species difficult if not impossible, to eradicate.

In 2023, following a possible identification, ICS introduced mandatory surveys to detect the presence of YCA on all of the six islands/atolls with a permanent presence. Following this, three islands - Alphonse, Desroches and Farquhar – confirmed the presence of YCA, prompting the Conservation NGO into action.  

​Desroches Island
On Desroches, the team identified YCAs in an area close to the tortoise sanctuary. This was immediately demarcated, and bait stations with small portions of jam were placed throughout the infested zone. Global Positioning System (GPS) points were taken to monitor eradication progress. By November 2024, the team had not recorded any more YCA on the island. “We acted quickly and effectively, and with the help of our partners, we have so far been able to prevent a re-introduction of YCA,” states Elisabeth Hein, the Conservation Officer on Desroches Island. However, the team is still cautious of a reintroduction through regular boats or flights that arrive on the island and remains vigilant in their monitoring of YCAs on the island.

Farquhar atoll
Farquhar Atoll presented a different challenge due to the extent of the infestation of YCA. Under the leadership of Seychellois Conservation Officer Priya Didon, the ICS team deployed jam bait alongside additional baits, such as Hymenopthor and Fipronil in heavily infested areas on Ile Du Nord where the human population lives. A colony of the Red-footed Booby (Sula sula) – a seabird species nesting on Ile Du Nord– was especially vulnerable given its proximity to the infested areas. Other small uninhabited islands of the atoll have so far remained unscathed. With the infested area demarcated, the team has so far deployed over 700 jam-baiting station on Ile Du Nord. “We are focusing on areas where the presence of YCA is confirmed. Other than that, we only use jam to check for their presence,” Didon states. However, heavy rainfall has hindered their progress, and the team is eager to get the situation under control.

Alphonse Group
On Alphonse, YCA was first detected in 2018 and more recently, has been spreading rapidly. Last year, the team launched a rigorous survey to identify the most infested areas on Alphonse, the main island in the group. According to the Conservation Officer Jack Coupland, the team deployed over 1,168 jam traps out of which 100 had one or more YCA in it. “The broad-scale baiting has helped us to identify areas where the ants are present. Now we are streamlining our efforts into a more localized bait deployment which will significantly reduce the population of YCA in a short period,” states Coupland. ICS is also relying on the expertise of its partners, including the hotels on the respective islands and the Islands Development Company (IDC) in this rigorous exercise which will also include using pesticides in areas where there are human residences and minimal risks to biodiversity. “This is a long-term eradication that will take different methods and concerted efforts by all the partners,’ adds Coupland.

Aride Island
Although Alphonse, Desroches and Farquhar, are the only islands with confirmed YCA infestations, ICS remains vigilant. Monthly surveys are now mandatory for all Conservation Centers, including Aride Island, a Special Nature Reserve which welcomes daily visitors from other islands. “We have amped up our biosecurity measures in view that there is a serious threat of YCA coming on Aride from Praslin,” states Emma Cotton, the Assistant Conservation Officer on Aride Island. “All visitors to the island are encouraged to bring as little as possible and should they disembark with bags, these are thoroughly searched for ants and other pests.” She adds that these measures will hopefully keep the ants away from the island which is an important nesting place for various species of seabirds.
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The impact of Yellow Crazy Ants (YCA) on biodiversity cannot be overstated, and the human and financial resources required for successful eradication are substantial. The control methods and protocols applied on islands with confirmed YCA infestations by ICS, demonstrate that only sustained commitment and significant investment can lead to their eradication.