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. 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?
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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! ICS wages war on feral cats, chickens and rats on Alphonse, soon to extend to other Islands11/2/2025 ![]() 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. 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. 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. 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. |
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