From May to October, the powerful Southeast Trade winds dominate the Seychelles—carrying strong waves and shifting sand along our shores. Both Mauritius and Seychelles have similar cooler conditions and relief rainfall, called ‘tilapli iver’ in Mauritian Creole. ​

​I had experienced rough seas and heavy swell (‘lahoule’) in Mauritius, where I was not able to leave my workplace on Ile aux Aigrettes. However, this was nothing compared to the swell of Seychelles. What I described as a storm in Mauritius, where we cannot go out to sea, is a normal day during the Southeast monsoon or ‘vann swet’.
 
I did not know that the Southeast Trade winds were such a powerful wave with a persistent coastal current. This unconscious mindset led to a broken toe in my left foot. The doctor was shocked when they saw a fully fractured toe from falling down in the sea during the ‘vann swet’ while pushing the boat to leave Aride Island. I was happy that it was not worse.
 
I have been amazed to witness the beach of Aride shrinking day after day. The long, beautiful beach moved and left behind rocks and gravel. This erosion that Aride faces is natural. The sand is sometimes transported slowly, or on other days, you would wake up and a huge shift had occurred, transporting sand along the beach to another side of the island or offshore.
 
Since July, the coastline of Aride has been dancing. This kinetic landscape isn’t static. Sand doesn’t just drift—it disappears, and reappears elsewhere in unpredictable ways. Today, however, we have experienced a return of sand on the beach.  This was such a relief for me. It is still unclear, but maybe this is a sign that the North West monsoon might come earlier this year.
 
Another thing that I was not prepared for when I came to Seychelles was the Sooty tern colonies. Once there was a shift from the North West winds to the Southeast Trade winds, the birds started to arrive. At Ile Aux Aigrettes in Mauritius, we used bird decoys and recordings of bird sounds to attract Sooty terns. This was not so on Aride Island, where we needed to count a population of more than 6,000 breeding pairs of Sooty terns. This experience on Aride Island has marked me for life.
In Mauritius, Sooty terns have been locally extinct in a few of our islets because of the culture of eating their eggs and the presence of rats within the colonies. It is such a blessing to encounter the young generation that is willing to protect the Sooty terns in Seychelles, and the presence of laws to protect this species from exploitation. So, the Southeast Trade winds or ‘vann swet’ is not such a bad thing after all. We welcomed the birds and said goodbye to the only beach on Aride Island. So, cheers to ‘vann swet’!

What happens when two different species, live together, mate and reproduce? A new ‘hybrid’ species is sometimes born. Hybridisation between species plays an important role in evolution, though there is considerable debate about its significance. Around 25% of plants and 10% of animals are known to form hybrids with at least one other species. There is even evidence of hybridisation in modern humans, with up to 4% of DNA from all people living today attributable to Neanderthals.

In an astonishing discovery, on the remote St. Francois Atoll in Seychelles' Alphonse Group, conservationists have confirmed a rare hybridisation event between two different tern species: a Roseate Tern (Sterna dougallii or ‘Dyanman Roz’ in Creole) and a Black-naped Tern (Sterna sumatrana or ‘Dyanman Likou Nwanr’ in Creole). This is the second recorded time hybridisation between the two said species has been recorded anywhere in the world, the first being in Australia in 2004.

The colony of Black-naped Tern on St Francois - one of the three islands of the Alphonse group - has been monitored by conservationists from the Island Conservation Society (ICS) since 2008. According to a scientific publication published recently, using photographic evidence and field observations, ICS observed a single Roseate Tern that established itself within the colony of Black-naped Terns. It was then observed successfully mating with a Black-naped Tern to produce a ‘hybrid’ offspring with distinctive features of both parent species. For example, it had distinct red legs, a characteristic unique to Roseate Tern and not Black-naped Tern. The egg from this pairing also exhibited mixed features, for example, they were noticeably larger than that of both species, but also had pigmentation resembling the eggs of the Roseate Tern. Over time, Conservationists also observed a ‘hybrid’ mating with another ‘pure’ Black-naped Tern; a process called ‘backcrossing’.

Although hybridisation is known to occur in avian species, the study does not speculate why the two species have chosen to mate together. One suggestion is that Terns, as observed in Fairy Terns, are very loyal to their mate and have a tendency to return to a previously visited location or site fidelity. Hence, since this first pair of a Roseate Tern and a Black-naped Tern has been successful at mating and producing offspring at St Francois; they returned annually to repeat the same process.  

The findings have crucial implications for the overall population of both species. Seychelles hosts the only known breeding grounds for Black-naped Terns in the African region. In addition to St. Francois Atoll, both species of tern also breed on nearby St. Joseph Atoll, Étoile (an uninhabited low-lying coral cay of the Amirantes group) and Farquhar Atoll. Black-naped Terns also breed on African Banks, Bancs Providence, Aldabra and Cosmoledo Atoll in the Outer Islands. In contrast, Roseate Terns once bred at several of the inner islands, but survive today only at Aride Island.

Black-naped Tern is a relatively scarce species in the Seychelles with an estimated 245 to 345 pairs – the entire breeding population of the Afrotropical region.  As for Roseate Tern, although it has a wide distribution around the world, its population is declining. It is estimated that 1,600 pairs of Roseate Tern visit the Seychelles from May to August to breed only. The majority (over 1,200 pairs) breed on Aride Island and rely on the protection of this island as a Special Reserve for their continued survival.

With both species being relatively in low numbers throughout Seychelles, this study highlights the need for further study to assess the extent of genetic mixing and its consequences on the evolution of both species on St Francois. Since this occurrence is only in one location, there is a risk that the population of the ‘pure’ Black-naped Tern will continue to inbreed within itself and with the Roseate Tern. However, the conservation implications of hybridisation are disputed. While the process might threaten rare species, it could also save a rare lineage from extinction by introducing genetic diversity. A "pure" lineage could harm conservation by lowering genetic diversity and adaptive potential, particularly in species with low populations.

It is uncertain what will happen to the unique and distinct characteristic of both species if this continues. This is a fascinating and rare aspect of avian biology that is unique to Seychelles and the Alphonse Group and that merits more research. This hybridisation phenomenon also underscores the fragility and biodiversity of Seychelles' ecosystem, particularly in the protected St. Francois Atoll—a critical site for seabird conservation.   

​My name is Russell Brown and I am a zoology student from England, studying in Cornwall. As part of my master’s, I had the opportunity to come out to Aride Island specifically to study the mice here. I aimed to gather information that would help estimate their population on the island, as well as study their home ranges. I was here during the gap between my third and fourth years of study to collect data for the research project.

Why This Research Is Important
Aride is home to many ground-nesting birds, including the White-tailed Tropicbird, Brown Noddies, and Shearwaters. It is currently unknown whether mice prey on their eggs or those of smaller species such as skinks. The first step in determining this is to estimate the number of mice on the island and understand how far an individual travels from its home. The information gained from this study could help guide future conservation efforts, including the potential eradication of mice from Aride, as this species was accidentally introduced by humans.

Of Boat Rides and Helicopters
While on Aride, I also assisted with the Sooty Tern census, cared for Aldabra Giant Tortoises, and excavated hatched Green Turtle nests—something I’m quite experienced in due to previous work on a turtle project. I was also heavily involved in launching the boat and other day-to-day tasks. At this time of year, leaving the island and taking trips to Praslin is an adventure. You can get knocked around by the waves and have to hold on tight. Being ‘airborne’ in the boat is my idea of heaven and was a highlight of my time on Aride. Another incredible experience was when a helicopter was used to airlift materials between a visiting barge and the island. Pulling straps off equipment while a helicopter hovers 20 metres above you is a truly unique feeling!
​
Life on the Island
In my spare time, one of my favourite things to do was explore and photograph the wildlife and scenery. Capturing the perfect shot of a bird in flight is incredibly rewarding! I never expected to stay for over two months on a nature reserve island—especially not during the Southeast monsoon—so when the opportunity came up, I had to take it. It has been an absolute honour to work alongside the incredible people who dedicate themselves to making the island a sanctuary for all kinds of wildlife, whether birds, reptiles, invertebrates, or plants. All of this comes together to make Aride Island an incredible and truly unique place!

Living on Aride
Living in such proximity to wildlife was one of the most rewarding—and sometimes surprising—parts of my time on Aride. I shared space with skinks in the kitchen, watched seabirds raise their chicks just metres from my bedroom, and frequently had to pause data collection for a stubborn tortoise refusing to approach any of the food items offered up during a feeding experiment. With no distractions from modern life, I learned to slow down, observe more deeply, and appreciate the complex dynamics of this fragile ecosystem.

Gazing into the ancient, weathered face of a giant tortoise felt like looking back in time. Their deeply wrinkled skin and deliberate, unhurried movements through the forest carried an unmistakable echo of the Jurassic era. Each tortoise had its distinct personality, some were shy whilst others were bold, and over my weeks on Aride, I came to know each of them individually.

The one tortoise that stood out from the very beginning was a remarkably spirited male known on the island as T-Rex. True to his name, T-Rex was the most fearless and charismatic of the group. While most tortoises would hiss and retreat into their shells at the sight of a human, T-Rex would march straight up to visitors, expectantly leaning in for scratches. His confidence and curiosity made him a constant presence, and by the time I left Aride, it felt like he had left just as much of a mark on me, as I had on him.

Aside from tortoises, as part of my research, I also had to learn to identify the flora found on Aride. This gave me a deep appreciation of the beautiful plant life found on Aride and across the Seychelles. I am especially going to miss wandering beneath the towering, crimson-leaved Indian-Almond trees on the coastal plateaux, and amongst the forests of endemic Wright’s Gardenia on the East hill. A highlight of the three months was being able to experience the Wright’s Gardenia in flower for the short few days that this occurs yearly.

Beyond my time on Aride, weekly shopping trips to Praslin gave me the chance to enjoy the delicious food from the reggae bar in Grande Anse every Friday. It was here that I developed a love for creole food, especially fish coconut curry, which may be the thing I miss most from the Seychelles!
However, it was the small community of people living on Aride that really made my time on the island. Whether it was one of the incredible fish BBQs Steve provided for us, or the support the island’s conservation officers, Emma and Maria, provided at the beginning of my data collection, I was made to feel welcome on the island and part of the community.

To Future Researchers
To future researchers and volunteers who are fortunate enough to spend time on Aride, my strongest recommendation would be to take the time to explore the island and fully embrace the stillness and peace that it offers. Aride is one of the rare places left on Earth where the natural world remains largely undisturbed, and thus where you can truly feel what it means to be immersed in the wild. 

​My name is Esme, and I’m from Scotland. I am currently studying at the University of Exeter for an MSc in Conservation and Biodiversity. As part of my dissertation, I have been lucky enough to conduct my research on Aride Island. My project focuses on a species few visitors to the island see, but one which may have significant implications on the island ecosystem: the house mouse. Whilst many other islands struggle with numerous invasive mammals, like rats and cats, Aride successfully eradicated these species; however, house mice remain.
 
Although small and often overlooked, mice have been linked to seabird declines on other islands around the world. Considering Aride is an important haven for seabird species in the Western Indian Ocean, with hundreds of thousands of birds nesting each year, understanding whether and how mice may be affecting them is essential. My goal was to begin establishing baseline data on the relative abundance of house mice across Aride’s different habitats. This is crucial information that could shape future eradication decisions.
 
This involved 6 weeks of live trapping across 3 different habitat types, focusing on areas where seabirds nest. Mice were marked with unique hair clips to tell individuals apart. Trapping ran for a week in each habitat, then was repeated after a short break.
 
But life on Aride isn’t just data and mouse traps. I don’t think anything quite prepares you for it. You can read all you like and look at countless pictures (I know I did), but waking up on the island for the first time, to the sound of seabirds and crashing waves, is a feeling you can't quite capture in a photograph. It isn't one stationary moment, it’s hundreds, woven together creating a feeling that words or pictures can’t quite capture.
 
What stood out most wasn’t a single moment, but the feeling of it all. Mostly Aride is the people, the small, dedicated team who welcomed us with open arms, who I cannot thank enough. We were incredibly lucky to learn from them and get stuck into other parts of the island’s conservation work too, from bird counts to turtle monitoring, gaining unforgettable hands-on experience.
 
If you’re thinking of volunteering or doing research on Aride, do it. It’s hard work, no doubt. But it’s also unforgettable. You’ll learn more than you expect, not just about wildlife, but about resilience, community, and yourself. 

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. 
​
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.