Seychelles frogs, new research


Metamorph Sooglossus sechellensis balanced on a 10 pence coin. Credit: Dr. Jim Labisko

From the University of Kent in England:

Conservationists discover hidden diversity in ancient frog family

April 11, 2019

Research scientists led by the University of Kent have uncovered hidden diversity within a type of frog found only in the Seychelles, showing that those on each island have their own distinct lineage.

The family tree of sooglossid frogs dates back at least 63 million years. They are living ancestors of those frogs that survived the meteor strike on earth approximately 66 million years ago, and their most recent common ancestor dates back some 63 million years, making them a highly evolutionarily distinct group.

However, recent work on their genetics led by Dr Jim Labisko from Kent’s School of Anthropology and Conversation revealed that until they can complete further investigations into their evolutionary relationships and verify the degree of differentiation between each island population, each island lineage needs to be considered as a potential new species, known as an Evolutionarily Significant Unit (ESU). As a result, Dr Labisko advises conservation managers they should do likewise and consider each as an ESU.

There are just four species of sooglossid frog; the Seychelles frog (Sooglossus sechellensis), Thomasset’s rock frog (So. thomasseti), Gardiner’s Seychelles frog (Sechellophryne gardineri) and the Seychelles palm frog (Se. pipilodryas).

Of the currently recognised sooglossid species, two (So. thomasseti and Se. pipilodryas) have been assessed as Critically Endangered, and two (So. sechellensis and Se. gardineri) as Endangered for the International Union for Conservation of Nature IUCN Red List. All four species are in the top 50 of ZSL’s (Zoological Society of London) Evolutionarily Distinct Globally Endangered (EDGE) amphibians.

Given the Red List and EDGE status of these unique frogs Dr Labisko and his colleagues are carrying out intensive monitoring to assess the level of risk from both climate change and disease to the endemic amphibians of the Seychelles.

Dr Labisko, who completed his PhD on sooglossid frogs at Kent’s Durrell Institute of Conservation and Ecology in 2016 said many of these frogs are so small and good at hiding the only way to observe them is by listening for their calls. Although tiny, the sound they emit can be around 100 decibels, equivalent to the sound volume of a power lawnmower.

Dr Labisko’s team are using sound monitors to record the vocal activity of sooglossid frogs for five minutes every hour, every day of the year, in combination with dataloggers that are sampling temperature and moisture conditions on an hourly basis

Dr Labisko said: ‘Amphibians play a vital role in the ecosystem as predators, munching on invertebrates like mites and mosquitos, so they contribute to keeping diseases like malaria and dengue in check. Losing them will have serious implications for human health.’

As a result of this study into the frogs, the research team will also contribute to regional investigations into climate change, making a local impact in the Seychelles.

Amphibians around the world are threatened by a lethal fungus known as chytrid. The monitoring of these sooglossid frogs will provide crucial data on amphibian behaviour in relation to climate and disease. If frogs are suddenly not heard in an area where they were previously, this could indicate a range-shift in response to warming temperatures, or the arrival of disease such as chytrid — the Seychelles is one of only two global regions of amphibian diversity where the disease is yet to be detected.

It may also impact on a variety of other endemic Seychelles flora and fauna, including the caecilians, a legless burrowing amphibian that is even more difficult to study than the elusive sooglossids.

Researchers know that caecilians can be found in similar habitats to the frogs, so they can use the frog activity and environmental data they are collecting to infer caecilian presence or absence and generate appropriate conservation strategies as a result.

Endemic, endangered and evolutionarily significant: cryptic lineages in Seychelles’ frogs (Anura: Sooglossidae) by Jim Labisko Richard A Griffiths Lindsay Chong-Seng Nancy Bunbury Simon T Maddock Kay S Bradfield Michelle L Taylor Jim J Groombridge is published in the Biological Journal of the Linnean Society.

Seychelles warbler reproduction, new study


This 21 March 2019 video says about itself:

Longer Life: Does The Seychelles Warbler hold the key? 2019 (Research)

A joint team of researchers from UEA and other universities in the UK and abroad have discovered that female birds age more slowly and live longer when they have help raising their offspring.

Researchers studied the relationship between ageing and offspring rearing patterns in the Seychelles warbler, and found that females who had assistance from other female helpers benefitted from a longer, healthier lifespan.

The findings help explain why social species, such as humans, which live in groups and cooperate to raise offspring, often have longer lifespans.

From the University of Groningen in the Netherlands:

Getting help with the kids slows down ageing in female birds

March 21, 2019

Seychelles warblers live and breed in family groups on the tiny island of Cousin. In each group, a dominant female and male reproduce. When helpers assist the with incubation and feeding of chicks, the dominant female breeders age more slowly and live longer, a study by biologists from the University of Groningen and colleagues from the Universities of East Anglia, Leeds, Sheffield, and Wageningen shows. The results, which are published in the journal Nature Communications on 21 March, indicate how cooperative breeding — which also occurs in other species, including humans — can increase life span.

The Seychelles warbler lives on Cousin Island in the Indian Ocean, measuring just 500 by 700 meters. Some fifty years ago, only a handful of birds survived. However, conservation efforts have led to a spectacular increase in the population, and new populations have been established by translocating birds to four other islands nearby. ‘There are about one hundred breeding territories on Cousin, each with a dominant male and female and a number of subordinates, which are often the offspring of the dominant pair’, explains University of Groningen biologist Martijn Hammers, lead author of the study.

Survival

Inside the groups, some — often female — subordinates may help the dominant female with the demanding tasks of incubation and raising chicks. ‘Not all dominant females get help’, explains Hammers. That is why the Seychelles warbler is well suited to investigate the effect of having helpers on aging in dominant breeders.

Ever since the 1990s, the Seychelles warblers on Cousin Island have been fitted with colored rings, so scientists are able to follow them over time. Hammers and his colleagues used data on survival and breeding success collected over fifteen years. In addition, they measured the shortening of telomeres, which can be used as a marker of condition and aging. Telomeres are repetitive DNA sequences at the end of chromosomes, which shorten in response to stress. Telomere shortening is a sign of biological aging, and in the Seychelles warbler, telomere length predicts survival.

Positive feedback

‘Our analysis showed that in dominant females who get help from subordinates, the shortening of the telomeres is slower than in birds who do not get help. Also, for the older dominant females, this help results in much better survival.’ Dominant males do not appear to benefit as much from having helpers, probably because they invest much less energy in breeding.

Hammers and his colleagues also discovered a positive feedback system: ‘Birds who get more help age more slowly and live longer. But older birds also tend to be more social and recruit more helpers.’ The helping subordinates are often daughters of the dominant female. In helping their mother, they raise siblings with whom they share genes.

Humans

The study shows how cooperative breeding could increase an individual’s lifespan. ‘Of course, the effects we have measured were within one generation, not between generations.’ Nevertheless, it supports a long-held hypothesis that cooperative breeding — which also is the norm in humans — can reduce the cost of raising young and may slow down the negative effects of aging. ‘It provides an explanation for why more social species tend to have longer lifespans’, Hammers concludes.

Seychelles island wildlife


This video says about itself:

Fregate About Everything and Enjoy This Tropical Paradise | National Geographic

9 September 2017

Frégate is part tropical paradise, part wild isle where a spectacular array of wildlife thrives in the island’s restored environments. Learn more about this amazing property: here.

Hawksbill sea turtle video


This is a hawksbill sea turtle video, recorded in the Seychelles.

Hawksbill turtles aren’t the only marine turtles threatened by the destabilizing effects of climate change, but a new study from researchers at Florida State University shows that this critically endangered species could be at particular risk: here.

Sooty tern migration geolocator research and hurricanes


This video says about itself:

Sooty Terns, Bird Island, Seychelles – 7th October 2015

The tern colony, with over a million birds present from April to October at the North end of the island.

From Science News:

Sooty terns’ migration takes the birds into the path of hurricanes

by Sarah Zielinski

10:35am, June 2, 2017

Hurricane season has officially begun in the North Atlantic, and it’s not just coastal communities that have to worry. A population of sooty terns off the southwest tip of Florida might want to worry, too. Depending on when and where storms hit, the terns could be in for a tough time. Their migratory route overlaps with the general path of hurricanes traveling from the waters off Africa up to the United States, a new study finds.

Sooty terns can be found all over the world. But the ones that nest in the Dry Tortugas National Park, west of Key West, are among the best known. The birds have been the subject of a long-term study that started back in 1959, and of other studies that stretch back into the early 20th century. Those studies revealed much about the birds’ growth and behavior, but not much about the terns’ migration.

In 2011, Stuart Pimm, an ecologist at Duke University, and colleagues attached geolocators to 25 sooty terns. A geolocator is “a remarkably stupid device,” Pimm says. It simply records how bright it is every 12 minutes. From that information, researchers can determine sunrise and sunset from day to day — and therefore approximate the birds’ location. But they have to retrieve the devices to get the data. That meant finding those 25 birds in a population of 80,000.

The researchers managed to find two.

But those two birds had some remarkable data. The geolocators recorded that the birds had experienced a 12-hour day in December, offset by five hours from Florida. That meant that they had been flying somewhere around the equator and were headed toward Africa.

But perhaps those two birds were outliers. So in 2014, Pimm’s group got some more sophisticated technology that could transmit a bird’s location. The new tech was also a lot more expensive, so the scientists were able to track only five birds. But the researchers also didn’t have to wait a year to get the data — or search for the birds among a population of thousands. “I would get up every day and check on where the birds were,” Pimm recalls.

At least some of the terns were flying south through the Caribbean, southeast along the coast of South America and then to the middle of the Atlantic, where they spent the winter, the team reports May 10 in PeerJ.

It’s a path that takes the birds straight up hurricane alley the long way, Pimm notes.

The researchers then took advantage of all those decades of banding birds. They matched historical reports from 1960 to 1980 of wrecked (that is, dead) sooty terns with tropical storms and hurricanes. Some years the birds were fine, but, Pimm says, “some years they get absolutely slaughtered.” If a storm hits at the wrong place and the wrong time, the birds are out of luck. Even if they manage to survive the high winds and heavy rains, they can be blown far off course. Hurricane Camille, for instance, took one poor sooty tern to the Great Lakes in 1969.

In some years, hurricanes may take out a small portion of the sooty tern population, but it doesn’t appear to be enough to cause big declines. Pimm worries, though, about what might happen in the future. It is not yet clear how climate change might change the severity or frequency of hurricanes — and thus affect the terns — but it is something to keep an eye on, Pimm says.

Ten bird species saved from extinction


This video from the Seychelles says about itself:

7 November 2016

A critical part of the North Island vision is the restoration of this tropical granite island under a programme known as the Noah’s Ark Project.
Having removed alien mammal and plant species from the island in an intensive restoration effort Seychelles White-Eyes – a small bird threatened with extinction – were introduced to the island.

From a population of only 25, there are now more than 100 birds on the island … a phenomenal success that has seen the IUCN Red List ‘downgrade’ the bird from Critically Endangered to ‘just’ Endangered.

From BirdLife:

10 birds that were saved from extinction

By Irene Lorenzo, 10 Jan 2017

BirdLife is proud to announce that Volume 2 of the Illustrated Checklist of the Birds of the World is now available to purchase. Published  by Lynx Edicions in association with HBW and BirdLife International, Volume 2 chronicles the world’s passerines (perching birds), and completes the most exhaustive illustrated checklist of birds ever compiled, with stunning, full-colour portraits of all the world’s 10,965 extant species.

But the truth is, we’re lucky to still have that many species on our planet. Deforestation, introduced species, climate change, illegal trapping. Nowadays it seems that all that humans do is destroy everything nature has to give. But it’s not all bad news. Every day all around the globe, passionate people are making an effort to help nature. And when they do, wildlife is quick to come back. Here are ten species that would have gone extinct if no one had intervened – classic examples of how intensive conservation efforts can, and do, pay off.

Seychelles White-eye Zosterops modestus

On the Seychelles, it’s a similar story to that told on remote islands around the globe; endemic species, wiped out by invasive species and deforestation. This olive-grey passerine was once so rare it was thought extinct for decades. However, conservationists have sought to expand its range by transferring it to other islands in the archipelago. It’s a risky tactic which has worked wonders for many other Seychellois bird species.The resultant population boom has seen it downlisted to Vulnerable in this year’s Red List. A white-eye for Seychelles, a black-eye for extinctions!

This 2012 video from New Zealand is called The Black Robin – A Chatham Island Story.

Black Robin Petroica traversi

Endemic to the Chatham Islands, in 1980 this robin had the smallest population of any bird recorded – just five. Like many other island species, it had evolved in a world without mammalian predators, and this clumsy flyer was no match for rats and cats when they arrived on the islands. As a result, it seemed doomed to extinction. Its spectacular recovery, following intensive tree planting and habitat management, is a world-renowned conservation success. Today there are around 230 Black Robins, all of which are descended from a single female, ‘Old Blue’. Although numbers continue to increase, it still has a very small population and is therefore classified as Endangered.

Rarotonga monarch

Rarotonga Monarch Pomarea dimidiata

Native to the Cook Islands, this monarch was once among the rarest birds in the world. It has been downlisted to Vulnerable owing to predator control and intense conservation efforts. The survival of the species remains dependent on the continuation of these efforts, and also a little luck. Random events such as cyclones or weed invasions can potentially drive it back to the Critically Endangered category in the blink of an eye.

This April 2016 video is called Seychelles Magpie Robins, Seychelles.

Seychelles Magpie-robin Copsychus sechellarum

Originally present on at least eight islands in the Seychelles, only around 13 birds remained on the island of Frégate in 1965. Seventeen years later, the recovery programme began: new habitats, increased food, nest defence, invasive species control and translocation to other islands made all the difference. Today, the species has bounced back, with a current population of 120 individuals and growing.

This 2011 video is called Rodrigues Warbler (Acrocephalus rodericanus).

Rodrigues Warbler Acrocephalus rodericanus

Habitat protection and reforestation, spurred by the need for watershed protection, have been key to the recovery of this species, aided by an absence of catastrophic cyclones. Native to the idyllic island of Rodrigues, Mauritius, its habitat is being fenced to exclude grazing animals, exotic plants have been removed and native species replanted. Thanks to these actions, it was downlisted from Endangered to Near Threatened in 2013.

This 2010 video is called Rodrigues Fody (Foudia flavicans).

Rodrigues Fody Foudia flavicans

Once abundant in the island of Rodrigues, Mauritius, this brightly coloured weaver declined drastically to around five pairs in 1968 after its native habitat was destroyed, which was followed by other issues such as droughts and (as ever) introduced species. Populations have increased as native and exotic woodland have recovered and expanded. Today the estimated total number ranges somewhere between 4,000 to 17,000 individuals and it is trending upwards.

This 2012 video from Michigan in the USA is about Kirtland’s warblers.

Kirtland’s Warbler Setophaga kirtlandii

The numbers of this North American warbler started decreasing at the beginning of the 20th century. Its optimal breeding habitat is very specific: fire-maintained homogeneous stands of 1-5 m tall jack pines on sandy soil. By replicating the effects of natural fires, its habitat has been expanded and numbers continue to increase, although its small range means it’s still Near Threatened.

This video is called Pale-headed Brush-finch endemic seen in Yunguilla reserve , in our Tumbesian and Ecuador endemic trip, February 2010.

Pale-headed Brush-finch Atlapetes pallidiceps

This Ecuadorian bird occupies an extremely small range and is restricted to one ocation. However, it has been increasing in numbers since 2003 thanks to habitat protection and control of nest parasites such as Shiny Cowbird Molothrus bonariensis. Its status, however, is precarious, and continued conservation efforts will be vital if it is to further improve.

This video from New Zealand is called North Island Saddleback (Philesturnus carunculatus rufusater).

North Island Saddleback Philesturnus rufusater

South Island Saddleback Philesturnus carunculatus

Double trouble! These two species have a small population confined to a number of predator-free islands around New Zealand. Owing to intensive conservation management measures such as predator and weed control, the populations are now increasing. They are considered Near Threatened because they only occur at a small number of sites and are therefore moderately susceptible to human impact and chance events such as cyclones.

This video says about itself:

There are only just over 600 South Island Saddleback left in New Zealand. In September 2014 40 were transferred from Motuara Island in the Marlborough Sounds to Adele Island in the Abel Tasman National Park by the Abel Tasman Birdsong Trust. This story which featured on TV3’s Campbell Live follows their journey.

Good Seychelles conservation news


From BirdLife:

Cousin Island Special Reserve – a success story

By Martin Fowlie, Tue, 15/04/2014 – 11:23

This video tells the conservation success story of Cousin Island Special Reserve, a former coconut enterprise now turned nature reserve in the Seychelles. Managed by local NGO and BirdLife Partner, Nature Seychelles, Cousin lies approximately 2 km from Praslin Island, Seychelles. The island became the World’s first internationally-owned reserve in 1968 when it was purchased by the International Council for the Protection of Birds (now Birdlife International) to save the last remaining population of the Seychelles warbler.

Cousin at the time had been cleared of its native vegetation and planted wall to wall with coconuts. Pigs, chickens and cattle had been introduced. Soon after its purchase, the Seychelles Government designated the island as a Nature Reserve under the Wild Animals and Birds Protection Act. In 1975, Cousin was designated a Special Reserve. This included the marine area up to 400m beyond the High Water Mark. Today, Cousin Island is a bird sanctuary; home to many endemic land birds and an important breeding site for seabirds. It is the most important rookery for Hawksbill turtles in the Western Indian Ocean. The island has been successfully restored to its natural vegetation and has received international awards for its conservation efforts and eco-tourism initiatives.

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