News and Blogs

  1. Latest News
  2. Cousin Island News
  3. Blue Economy Seychelles
  4. Green Health Blog
  • Issue 11 of the WIOMSA Magazine focusing on Ecosystem Restoration is out!

    This issue focuses on restoring damaged coastal ecosystems and includes Nature Seychelles' coral reef restoration project, which is celebrating 10years of action. https://www.wiomsa.org/wp-content/uploads/2020/09/WIOMSA-Magazine-Issue-11_September2020.pdf and the Nairobi Convention have jointly produced two issues of the WIOMSA Magazine focusing on restoring damaged coastal ecosystems. The publication of this issue of the Magazine[…]

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  • IUCN Congress Newsletter: Remaining ocean champions, not victims

    Cousin Island Special Reserve was the island famously bought for conservation by BirdLife International in 1968, and it is now managed by Nature Seychelles. I visited the island at the beginning of the year to inspect catastrophic coastal erosion that had occurred, and it was the first time I had[…]

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What's On at Nature Seychelles

Conservation Boot Camp

Bootstrap your career in conservation. Whether you want to to break into conservation or bolster your experience and knowledge, join the world's first Conservation Boot Camp where you can gain a much coveted, unique and exclusive experince working in a world renowned and multiple award winning nature reserve...Read more

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Implementing the SDGs

At Nature Seychelles we are committed to working with government, development partners and donors in implementing relevant actions, in particular, looking at certain goals where we can build on our existing strengths. Read more

Seychelles Wildlife

Natural environment of the Seychelles

Seychelles is a unique environment, which sustains a very special biodiversity. It is special for a number of different reasons. These are the oldest oceanic islands to be found anywhere...

Bird Watching

Seychelles is a paradise for birdwatchers, you can easily see the unique land birds, the important sea bird colonies, and the host of migrants and vagrants. Some sea bird...

Seychelles Black Parrot

Black Parrot or Kato Nwar in Creolee is brown-grey in colour, not truly black. Many bird experts treat it as a local form of a species found in Madagascar and...

Fairy Tern

The Fairy (or white) Tern is a beautiful bird seen on all islands in Seychelles, even islands like Mahe where they are killed by introduced rats, cats and Barn Owls....

Introduced Land Birds

A little over two hundred years ago, there were no humans living permanently in Seychelles. When settlement occurred, people naturally brought with them the animals and plants they needed to...

Native Birds

Although over 190 different species of bird have been seen on or around the central islands of Seychelles (and the number is increasing all the time), many of these are...

Migrant Shore Birds

Shallow seas and estuaries are very rich in invertebrate life. Many birds feed on the worms, crabs and shellfish in these habitats; often, they have long bills for probing sand...

Seychelles Magpie Robin

The most endangered of the endemic birds, Seychelles Magpie Robin or Pi Santez in Creole, came close to extinction in the late twentieth century; in 1970 there were only about...

Seychelles Blue Pigeon

The Seychelles Blue Pigeon or Pizon Olande in Creole, spends much of its life in the canopy of trees and eats the fruits of figs, bwa dir, ylang ylang and...

Seychelles White-eye

The Seychelles White-eye or Zwazo Linet in Creole, is rare and endemic. They may sometimes be seen in gardens and forest over 300m at La Misere, Cascade and a few...

Seychelles Black Paradise Flycatcher

The Seychelles Black Paradise Flycatcher or the Vev in Creole is endemic to Seychelles, you cannot find this bird anywhere else on earth. Although it was once widespread on...

Seychelles Sunbird

The tiny sunbird or Kolibri in Creole, is one of the few endemic species that has thrived since humans arrived in the Seychelles.

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Achievements

  • Stopped near extinctions of birds +

    Down-listing of the critically endangered Seychelles warbler from Critically Endangered to Near Threatened. Other Seychelles birds have also been saved including the Seychelles Magpie Robin, Seychelles Fody, and the Seychelles
  • Restored whole island ecosystems +

    We transformed Cousin Island from a coconut plantation to a thriving vibrant and diverse island ecosystem. Success achieved on Cousin was replicated on other islands with similar conservation activities.
  • Championed climate change solutions +

    Nature Seychelles has risen to the climate change challenge in our region in creative ways to adapt to the inevitable changing of times.
  • Education and Awareness +

    We have been at the forefront of environmental education, particularly with schools and Wildlife clubs
  • Sustainable Tourism +

    We manage the award-winning eco-tourism programme on Cousin Island started in 1970
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Seychelles warbler: infidelity increases offspring survival

seychelles warblerWhy does female infidelity occur so frequently throughout the animal kingdom? A 10-year study from the University of East Anglia shows that Seychelles warblers may increase their offspring’s survival through their infidelity.

Why does female infidelity occur so frequently throughout the animal kingdom? A 10-year study from the University of East Anglia shows that Seychelles warblers may increase their offspring’s survival through their infidelity.

Although in many animals females may pair up with a specific ‘Social’ mate who helps raise the pairs’ offspring, DNA fingerprinting studies across a wide range of animals reveals that offspring may often be sired by males other than the pair male.

What has perplexed scientist is why females engage in such infidelity – what is the benefit of being fertilised by these other males – males which do not contribute towards raising the offspring.

Despite pairing with the same male for life, female Seychelles warbler birds often prefer to be fertilised by other males, and this appears to increase the genetic quality of their offspring.

The study has shown that these extra-pair fertilisations can result in a higher diversity of specific genes which detect disease and trigger an immune response in offspring. As a consequence, the offspring survive longer probably as a result of having greater resistance to a wider range of diseases..

The research ‘MHC-dependent survival in a wild population: evidence for hidden genetic benefits gained through extra-pair fertilisations’ has been lead by Dr David Richardson (UEA) and is published today in Molecular Ecology

Since 1997 more than 97 per cent of warblers on the tiny island of Cousin in the Seychelles were ringed, blood sampled, and their breeding attempts followed. The researchers monitored the fate of 160 birds hatched on the island between 1997 and 1999, over 10 years.

They found that females paired to males with a low diversity of disease-detecting genes (major histocompatibility complex or MHC) elevate the gene diversity of their offspring by gaining extra-pair fertilisations from males with higher diversity. This extra pair fertility was found to be common – accounting for 40 per cent of offspring.

Importantly, the offspring born as a result of this female infidelity have higher genetic diversity at these disease-detecting genes than they would have had if sired by the cuckolded pair male.

However they were not found to be higher than the population average.

The researchers then found a positive association between diversity of MHC genes and juvenile survival. A higher than median MHC diversity was found to increase lifespan more than two-fold.

They also found that offspring with a specific rare gene variant (Ase-ua4) had a five times longer life-expectancy than offspring without this allele. However these birds did not necessarily have a greater MHC diversity. It is thought that individuals with this rare variant of MHC genes may survive longer because these rare variants better resist diseases that have already evolved to evade more common variants.

Dr Richardson said: “We first tested whether extra-pair offspring have a survival advantage compared to within-pair offspring. Then we tested whether there are genetic benefits to the patterns of the MHC-dependent extra-pair fertilizations observed in this species.”

“We did not find any evidence for genetic benefits of extra-pair fertilisations per se, as on average extra-and within-pair offspring survived equally well.

“However, by not being faithful to a pair male with low MHC diversity, females are ensuring that their offspring do not end up with below average levels of MHC diversity and therefore lower survival.

“We have shown that the association between survival and MHC diversity levelled off with increasing diversity, so choosing males with above average MHC diversity would not have resulted in any additional fitness benefits for the offspring.

“One thing that remains unknown however, is what mechanism drives the patterns of MHC-dependent extra-pair mate choice. Experiments are needed to determine whether females actively choose more diverse MHC males or whether other factors like male-male competition or sperm competition play a role.”

The study was lead by the University of East Anglia, with colleagues from the University of Sheffield, the University of Groningen and Nature Seychelles.

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Since 1998.

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Tel:+ 248 4601100

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Email: nature@seychelles.net