‘Extinct’ Seychelles turtle did not exist


West African mud turtle Pelusios castaneus (credit: © Mark-Oliver Rödel)

From the Senckenberg Research Institute and Natural History Museum in Germany:

One Extinct Turtle Less: Turtle Species in the Seychelles Never Existed

Apr. 4, 2013 — The turtle species Pelusios seychellensis regarded hitherto as extinct never existed. Scientists at the Senckenberg Research Institute in Dresden discovered this based on genetic evidence. The relevant study was published today in the journal PLOS ONE.

Turtles are the vertebrates under the greatest threat. Among the approximately 320 turtle species, the species confined to islands have been especially hard hit — humans have caused the extinction of a whole number of species. One of them — or at least it was thought so — is the Seychelles mud turtle Pelusios seychellensis. Just three specimens were collected at the end of the 19th century; they are still kept at the Natural History Museum in Vienna and the Zoological Museum in Hamburg.

Despite an intensive search for this species, which was declared as “extinct” by the International Union for Conservation of Nature (IUCN), no further specimens have been found since those in the 19th century. “Consequently, it was assumed the species had been exterminated,” says Professor Uwe Fritz, director of the Museum of Zoology at the Senckenberg Natural History Collections in Dresden. The Dresden biologist states quite clearly that this is not true. “We have examined the DNA of the original specimen from the museum in Vienna and discovered that these turtles are not a separate species.”

The genetic analyses have shown that this supposed Seychellois species is in reality another species, Pelusios castaneus, that is widespread in West Africa. “The species Pelusios seychellensis has therefore never existed,” adds Fritz. “In fact, for a long time researchers were amazed that the supposed Seychelles turtles looked so deceptively similar to the West African turtles. But due to the great geographic distance, it was thought this had to be a different species, which is why the assumed Seychelles turtles were also described as a new species in 1906.”

Another species classified as native therefore disappears from the list of Seychelles species. Last year, Fritz and his team had already proved that another mud turtle species, Pelusios subniger, was not endemic to the Seychelles but had been introduced by man.

“In the Seychelles there is therefore at most one mud turtle species that could be native. And even with this species we are still uncertain whether it really is endemic,” says Fritz. So far, the biologists from Dresden have not been able to explore this possibility due to the incomplete sampling available, however.

“But what is certain even now is that the protection programmes for turtles in the Seychelles will have to be revised, so that truly endemic animal species are protected and the scarce funds available for species protection are put to good use,” says Fritz in conclusion.

Hawksbill turtles’ love life discoveries


This is a hawksbill turtle video.

From the BBC:

4 February 2013 Last updated at 03:26

Hawksbill turtles‘ monogamous sex life revealed

By Michelle Warwicker BBC Nature

The sex lives of critically endangered hawksbill turtles have been revealed by scientists studying the animals in the Seychelles.

Previously, little had been understood about the mating habits of the turtles, which live underwater and often far out at sea.

Researchers were surprised to find that the turtles are mainly monogamous, with females storing sperm from one male and using it to fertilise multiple egg clutches.

The study, led by researchers from the University of East Anglia, Norwich, UK, was published in the online journal Molecular Ecology.

“Sperm storage” is found in animals including reptiles, birds and some turtles, tortoises and terrapins.

Females can store viable sperm from multiple males for long periods of time, meaning that their egg clutches are sometimes fertilised by more than one father.

Researchers carried out DNA testing from hawksbill turtle hatchlings on Cousine Island in the Seychelles to identify how many males were involved in fertilising eggs during a breeding season.

The tests revealed a monogamous mating system: most egg clutches were sired by just one male, and no males had fertilised more than one female during the 75-day season.

“We were surprised that they were so monogamous because actually… genetic monogamy is actually the exception in most animals, not the rule,” said research team member Dr David Richardson.

The findings show that “there are plenty of males out there” for females to mate with.

“It’s very unlikely that it’s just a few males hanging around offshore”, said Dr Richardson. “We think they’re mating with males a long way away, wherever they’re normally foraging and feeding which can be all over the western Indian Ocean,” he added.

The number of hawksbill turtle males contributing to the next generation is important for the species’ survival because it results in higher levels of genetic variation.

Genetic variability “means [the turtles] can respond to new threats, new diseases or anything that comes along,” explained Dr Richardson.

Hawksbill turtles were identified as Critically Endangered by the International Union for the Conservation of Nature after years of being hunted for their shells, which were prized in the now illegal decorative tortoiseshell trade.

Found in tropical waters around the world, females turtles gather at onshore nesting sites such as Cousine Island every few years to lay around five clutches of eggs during the season.

Mating often takes place out at sea, but according to the study, by testing DNA samples from hatchlings on the island, the researchers were able to gather information that would have been impossible from observation alone.

Dr Richardson told BBC Nature that this study, combined with independent reports of hawksbill turtle numbers rising, indicates that “in terms of conservation… maybe we are in a better place than we thought.”

The team hopes their study may help conservationists working on Cousine Island to understand more about the lives of the animals and to focus their efforts.

See also here.

Seychelles paradise flycatchers helped by schoolchildren


Seychelles paradise flycatchers, male and female

From BirdLife:

Water for birds: Club installs bird baths for Seychelles Paradise Flycatcher

Wed, Jan 23, 2013

Eight bird baths were installed around the the island

An after school clubs called the Friends of the Flycatcher is helping to keep Seychelles Paradise Flycatcher, Terpsiphone corvina watered. The club based on La Digue, Seychelles third largest inhabited island, has installed eight bird baths on different locations on the island for the benefit of the iconic bird locally known as the Veuve. The baths were set up at the Veuve Reserve, the La Digue School, the Flycatcher Lodge, Villa Veuve, and the Community Centre at La Passe.

A source of water is as important to birds as is food. Apart from drinking, water also removes dust, loose feathers, parasites and other debris from a bird’s plumage. Bird baths are man-made shallow pools from which birds can drink, bathe, preen or cool off. They are normally made in the form of a basin.

Seychelles Paradise Flycatcher favours native Badamier Terminalia catappa and Takamaka dominated Calophyllum innophylum broad-leaved plateau woodland in proximity to wetland areas for its habitat. The wetlands and marshes are also important as breeding grounds for insects, which the birds eat.

But in the dry season the marshes dry up, and the birds have been observed going to domestic sources of water which places them in danger of drinking detergent and being caught by cats while on the ground, says Josiana Rose of the Seychelles National Parks Authority (SNPA), and the education officer at the Veuve Reserve.

“Provision of water baths for the flycatcher will give them safe and easy access to water for drinking and bathing during the dry season that persists for many months,” she says.

Nature Seychelles (BirdLife Partner) and the SNPA have been promoting the conservation of the Critically Endangered flycatcher through an advocacy and education project whose aim is to help protect the species in its stronghold on La Digue. The project is part of the BirdLife Preventing Extinctions Programme and is supported by Species Champion, Viking Optical. It’s under this partnership that the Friends of the Flycatcher was started at the school.

Although still in its infancy, the club has been involved in a number of activities including cleaning up the island on World Clean-up Day and planting trees in the Veuve Reserve.

The baths are made of fibre glass and stand up to four feet above the ground on a wooden base.

Seychelles millipedes and invasive plants


This is a video of a Seychelles giant millipede, attacked by a crab.

Vulnerable Seychelles giant millipedes change their behaviour in response to the presence of non-native plants, a study finds.

Photos are here.

Seychelles giant tortoise in Britain


From daily The Morning Star in England:

Darwin’s at home in his new wildlife shell-ter

Friday 17 February 2012

Darwin, the first giant tortoise to be donated to Britain by the Seychelles, settled into his new home today.

The aldabra tortoise has been presented to the Cotswold Wildlife Park as part of a conservation partnership with the Seychelles National Botanical Gardens.

The aldabras originate from the inaccessible Aldabra lagoon in the Indian Ocean and are listed as an endangered species.

He’s already 25 years old but he could be in Burford, Oxfordshire, for a while – aldabras can live to 150.