Galapagos tortoises eat invasive plants


This 2014 video is called Galapagos Islands RARE ANIMALS – Giant Tortoise.

From Washington University in St. Louis, USA today:

Endangered tortoises thrive on invasive plants

3 hours ago

Most research on the role of introduced species of plants and animals stresses their negative ecological impacts. But are all introduced species bad actors?

In one fascinating case the answer might be no. The iconic giant tortoises of the Galapagos Islands are thriving on a diet heavy on non-native plants. In fact, the tortoises seem to prefer these plants to native ones.

Introduced plants began to increase in abundance on the Galapagos Islands in the 1930s as native highland vegetation was cleared for agriculture, and the rate of introductions has been increasing ever since.

The giant tortoises, for their part, seem headed in the opposite direction. Until the late Pleistocene epoch, they were found on all the continents except Antarctica. Today they survive in only two locations: the Aldabra Atoll in the Indian Ocean, and the Galapagos Archipelago in the eastern Pacific Ocean. In the Galapagos, all of the remaining subspecies are considered vulnerable or endangered.

But now in a surprising turn of events, field research in the Galapagos shows that introduced plants make up roughly half the diet of two subspecies of endangered tortoise. What’s more, these plants seem to benefit the tortoises nutritionally, helping them stay fit and feisty.

The research, published in the March issue of Biotropica, was conducted by Stephen Blake, PhD, an honorary research scientist at Washington University in St. Louis and Fredy Cabrera of the Charles Darwin Foundation in the Galapagos.

“Biodiversity conservation is a huge problem confronting managers on the Galapagos Islands, “Blake said. “Eradicating the more than 750 species of invasive plants is all but impossible, and even control is difficult. Fortunately, tortoise conservation seems to be compatible with the presence of some introduced species.”

Counting bites and bouts

The study was done on the island of Santa Cruz, an extinct volcano that is home to two species of giant tortoise, but also to the largest human population in the Galapagos. Farmers have converted most of the highland moist zones to agriculture and at least 86 percent of the highlands and other moist zones are now degraded by either agriculture or invasive species.

In earlier work, Blake had fitted adult tortoises on Santa Cruz with GPS tags and discovered that they migrate seasonally between the arid lowlands, which “green up” with vegetation only in the wet season, to the meadows of the highlands, which remain lush year-round.

“This struck us as pretty odd, ” he said, “since a large Galapagos tortoise can survive for a year without eating and drinking. This is why sailors would collect the tortoises to serve as a source of fresh meat aboard ship.”

“Why would a 500-pound animal that can fast for a year and that carries a heavy shell haul itself up and down a volcano in search of food?,” Blake said. ” Couldn’t it just wait out the dry season until better times came with the rains?”

The answer, of course, depends on the tortoise’s energy balance. But the only detailed study of tortoise foraging the scientists were aware of had been completed in 1980, “largely before the explosion of introduced and invasive species hit the Galapagos,” Blake said.

Over a period of four years, the scientists followed tortoises in the field and, during 10-minute “focal observations” recorded every bite the tortoises took, the plant species and which part they ate. As an additional measure of the fruits the tortoises were eating, the scientists also counted and identified seeds (sometimes more than 1,000) in tortoise dung piles.

Counts of bites and bouts (defined as all feeding on a given species during the focal observations) showed that tortoises actually spent more time browsing on introduced species than on native ones.

“We weren’t really that surprised,” Blake said. “Consider it from a tortoise’s point of view. The native guava, for example, produces small fruits containing large seeds and a small amount of relatively bitter pulp in a thick skin. The introduced guava is large and contains abundant sweet pulp in a thin, pliable skin.”

The team, which included Sharon Deem, a wildlife veterinarian and epidemiologist at the St. Louis Zoo, also assessed the tortoises’ health and nutritional status, weighing them by suspending them from a spring balance and taking blood samples.

All of the indicators the scientists studied suggest that introduced species in the diet have either a neutral or positive effect on the physical condition of the tortoises. Introduced species may even help tortoises to improve their condition during the dry season.

Since a return to “pristine” conditions is unlikely on the Galapagos, it is heartening to learn that this may not be all bad news for the islands’ charismatic megaherbivores.

Rare tortoise babies born on Galapagos island


This video says about itself:

5 March 2015

Baby tortoises were born on the Island of Pinzon, something that likely hasn’t happened since 1880. CNN’s Natalie Allen has this story.

From Associated Press:

Scientists cheered by birth of Galapagos tortoises in wild

Posted: Mar 14, 2015 5:33 AM Updated: Mar 17, 2015 8:36 AM

By GONZALO SOLANO

QUITO, Ecuador – For the first time in a century, babies of the endangered Pinzon giant tortoise have been born in the wild in the Galapagos islands, scientists said.

An expedition in 1970 found only 19 adult tortoises on the archipelago’s Pinzon island, averaging 70 years old, so scientists removed them to start a captive breeding program on Santa Cruz island. The program produced juveniles that were transplanted back to the island, which is the only place the species is found.

Danny Rueda, who is in charge of conservation and restoration of ecosystems in the Galapagos, told The Associated Press that in December six infant Pinzons were found to have been born on the island.

He said there are now 650 juvenile and adult tortoises on Pinzon.

Rueda said the reintroduction of the tortoise was helped by the 2012 campaign to eradicate rats that infested Pinzon and other islands in the archipelago after being introduced long ago by passing ships. The rats prevented the reproduction by tortoises and other species.

“Finding the six baby tortoises tells us that the process of eradicating rats succeeded,” he said.

“We have begun to see that the ecosystem has begun to restore itself” on Pinzon, Rueda added. “It is a process that takes a long time. But the first step is the birth of tortoises in their natural habitat, which a century ago did not happen.”

The Galapagos, an Ecuadorean territory in the Pacific about 1,000 kilometers (620 miles) from the mainland, was declared a World Heritage Site by UNESCO in 1978 because of its unique land and marine animals and vegetation. That flora and fauna helped inspire Charles Darwin’s theory of evolution.

See also here.

Prehistoric turtles and climate change


This March 2014 video is called Global Warming 56 Million Years Ago: What it Means for Us .

From the University of Florida in the USA:

Tropical turtle discovery in Wyoming provides climate-change clues

Published: February 23 2015

Tropical turtle fossils discovered in Wyoming by University of Florida scientists reveal that when the earth got warmer, prehistoric turtles headed north. But if today’s turtles try the same technique to cope with warming habitats, they might run into trouble.

While the fossil turtle and its kin could move northward with higher temperatures, human pressures and habitat loss could prevent a modern-day migration, leading to the extinction of some modern species.

The newly discovered genus and species, Gomphochelys (pronounced gom-fo-keel-eez) nanus, provides a clue to how animals might respond to future climate change, said Jason Bourque, a paleontologist at the Florida Museum of Natural History at UF and the lead author of the study, which appears online this week in the Journal of Vertebrate Paleontology</em>.

The wayfaring turtle was among the species that researchers believe migrated 500-600 miles north 56 million years ago, during a temperature peak known as the PaleoceneEocene Thermal Maximum. Lasting about 200,000 years, the temperature peak resulted in significant movement and diversification of plants and animals.

“We knew that some plants and lizards migrated north when the climate warmed, but this is the first evidence that turtles did the same,” Bourque said. “If global warming continues on its current track, some turtles could once again migrate northward, while others would need to adapt to warmer temperatures or go extinct.”

The new turtle is an ancestor of the endangered Central American river turtle and other warm-adapted turtles in Belize, Guatemala and southern Mexico. These modern turtles, however, could face significant roadblocks on a journey north, since much of the natural habitat of these species is in jeopardy, said co-author Jonathan Bloch, a Florida Museum curator of vertebrate paleontology.

“If you look at the waterways that turtles would have to use to get from one place to another, it might not be as easy as it once was,” Bloch said. “Even if the natural response of turtles is to disperse northward, they have fewer places to go and fewer routes available.”

To put the new turtle in evolutionary context, the researchers examined hundreds of specimens from museum collections around the country, including turtles collected during the 1800s housed at the Smithsonian Institution. Co-author Patricia Holroyd, a vertebrate paleontologist at the University of California, Berkeley, said the fossil history of the modern relatives of the new species shows they could be much more wide-ranging, if it were not for their restricted habitats.

The Central American river turtle is one of the most endangered turtles in the world, threatened by habitat loss and its exploitation as a human food source, Holroyd said.

“This is an example of a turtle that could expand its range and probably would with additional warming, but — and that’s a big but — that’s only going to happen if there are still habitats for it,” she said.

Protecting endangered loggerhead sea turtles


This 2014 video is about baby loggerhead turtles hatching on Kuriat island in Tunisia.

From BirdLife:

From the Atlantic to the Mediterranean, turtle conservation overcoming similar challenges

By Shaun Hurrell, Thu, 12/02/2015 – 16:40

The Critical Ecosystem Partnership Fund (CEPF) is funding three projects that are protecting Endangered loggerhead sea turtles

An uninhabited island with beautiful beaches might seem like a safe place for a rare species of turtle to nest, but Kuriat Island of Tunisia is swamped every summer by thousands of tourists. Even the fishermen who frequent the island to rest can be unaware that the island is very important for the loggerhead sea turtle Caretta caretta – the only place in Tunisia where this Endangered species buries its eggs in the sand. Sea turtle populations are devastated from bycatch in fishing nets so any hatchlings under the sand need all the help they can get to reach the sea.

This is why a local conservation group called ‘Association des Fans de la Chebba (AFC)’, partnered by Notre Grand Bleu (NGB) and funded by CEPF, is working to raise awareness of the plight of the turtles, and has successfully gathered support from fishermen in the Chebba region of Tunisia and visiting tourists.

Realising a daily presence was needed during nesting and tourist season, and having marked nests on the beach for their protection, AFC and NGB constructed a cabin providing information and flyers to best educate the two target audiences. By providing clear explanations and advice, the project has turned the unexpected emergence of turtles from the sand (prone to accidental destruction) into a wonderful wildlife spectacle for tourists – some of whom now voluntarily help hatchlings reach the sea. Watch their video [above]!

Over 100 artisanal fishermen have been introduced to measures to prevent the accidental capture of adult turtles. But if accidentally caught, they are being eaten. At a scale where a few hundred are caught each year here in nets, this educational project could eliminate turtle bycatch in Tunisia before a black market for their illegal meat grows.

In three months, over 4000 national and foreign tourists, plus around 100 artisanal fishermen visited the cabin. Over 500 children attended in a special organised visit, a great success for the project and great hope for the future of Kuriat Island as a protected area and location for sustainable tourism.

Following protected hatchling loggerhead sea turtles into the Mediterranean Sea, we head south-west into the Atlantic Ocean, where the islands of Cape Verde face very similar challenges for turtle conservation, albeit at a different scale. Within the remit of the CEPF Mediterranean Basin Biodiversity Hotspot, there are two projects currently conserving turtles in Cape Verde – world famous for its many species of turtle, and for its tourists.

Same problem, different location and scale

BIOS.CV (Association for the Conservation of the Environment and Sustainable Development) are working on a project called Environmental Initiatives to Enhance Ecofriendly Tourism in Boa Vista Island, Cape Verde. Most tourists are directed to all-inclusive resorts and are blind to the island’s wildlife, way of life, and their impact on it. Identifying the country’s current lack of regulated and sustainable tourism, BIOS.CV are working hard to raise awareness of the islands importance for wildlife, and to enhance ecotourism that will benefit the local communities. As well as developing information on the beach, they have put up posters in Boa Vista airport and are working with hotels to ensure tourists reduced impacts of turtle and bird nesting, and on the island’s biodiversity.

Cape Verde has the world’s third largest loggerhead sea turtle nesting population with 90% of the nests on Boa Vista. Most recently, BIOS.CV prepared and promoted a map for cyclists and drivers to avoid turtle nests.

“We want to show to both the local population and the tourism sector that tourism is highly dependent on effective conservation of the environment and the welfare of the local communities – and this is only possible through eco-friendly and sustainable tourism practices,” said Elena Abella from BIOS.CV.

A short hop across to Cape Verde’s nearby island of Santa Luzia, and we find another example of a CEPF project conserving turtles. As part of a major CEPF project entitled Protecting Threatened and Endemic Species in Cape Verde: A Major Island Restoration Project run by SPEA (Sociedade Portuguesa para o Estudo das Aves; BirdLife in Portugal) and their local partner Biosfera1, like AFC in Tunisia, also have a daily presence at a nesting site to protect loggerhead sea turtles. Biosfera1 set up a camp in a National Park on the island of Santa Luzia to monitor nests, survey other biodiversity and to assess threats. All nests at risk (because they are located in flood-prone areas), are transferred into a hatchery near the camp where the eggs can complete their development.

But on Cape Verde, a further complication is that more than 500 female turtles are affected by illegal poaching and predation by feral cats each year. Again, awareness is key. Biosfera1 have set up a surveillance scheme that involves local fishermen and is monitored by staff and volunteers to prevent illegal activity.

The project has already recorded a decrease in turtle poaching during the surveillance period, but it is hoped that through Biosfera1’s work with fishermen to emphasise the value of wild turtles over those on the dinner plate, this trend will continue afterwards.

Saving Madagascar’s ploughshare tortoises


This 4 February 2015 video from the Durrell Wildlife Conservation Trust about Madagascar says about itself:

100th Ploughshare [tortoise] release

Young loggerhead turtle survives beaching in the Netherlands


This video from the USA says about itself:

25 September 2012

An educational video by SEE Turtles about sea turtle migrations including leatherbacks and loggerheads.

Translated from the Dutch RAVON herpetologists:

Loggerhead survives stranding

Wednesday, February 4th, 2015

On Sunday, January 11th a young loggerhead turtle stranded on the beach at Wassenaar. It was the second turtle on a Dutch beach in four weeks because on December 20, 2014 at Den Helder a young Kemp’s ridley turtle had been found. This animal was transferred to Rotterdam Zoo but died that night. The loggerhead is more fortunate.

The young loggerhead (Caretta caretta) was noticed in the morning by hikers in the low surf on the beach, near Berkheide, and was reported to Ecomare museum and the animal ambulance in The Hague. The turtle was then picked up by the animal ambulance and delivered at Rotterdam Zoo. Rotterdam Zoo is along with Burgers’ Zoo the designated place for accommodation of stranded sea turtles.

Upon entering Rotterdam Zoo it was noted that the animal was very apathetic, felt cold, but apparently had no injuries. Also an X-ray examination revealed no significant issues. However, abnormal liver and kidney values were found in the blood. The turtle had a weight of 2.1 kg and a shell with a length of 24.5 centimeters. The first night the turtle was housed in a small amount of water at 14 degrees Celsius to prevent drowning. The next morning, the animal swam around to everyone’s surprise. The water level was increased to 80 centimeters and the temperature was raised in four days time in small increments to 20 degrees. After six days the turtle started feeding and also its blood levels became a lot better. The coming months the turtle will remain in Rotterdam Zoo to recuperate and to see if it has no permanent damage on account of its adventure in the cold North Sea. Then people will look where the animal can be freed again.

The first mention of a loggerhead turtle [in the Netherlands] was in 1707. This animal was exhibited after its discovery in a café in Amsterdam, where the animal died after a few days. Since then, there are seven other reports from the Netherlands. Insofar as is known, only the animal that washed ashore in 2008 at Groote Keeten (Noord-Holland province) survived. This weakened animal was rehabilitated in the aquarium of Burgers’ Zoo and later freed off the Portuguese coast.

The current one is probably from Florida (USA) where a large population nests. Juveniles make journeys with the Gulf Stream to the Azores and Cape Verde Islands after which they return to the coast of America.

An article about the stranding of the young loggerhead will soon appear in the RAVON journal.

Loggerhead sea turtles, new discovery


This video from the USA is called Loggerhead sea turtles hatching. Sebastian, Fl.

From NOAA Fisheries West Coast Region in the USA:

Surprise discovery off California exposes loggerhead ‘lost years’

January 13, 2015

Summary:

North Pacific loggerhead turtles hatch in Japan, with many later reappearing 6,000 miles away off southern Baja California to forage. The sighting late last year of numerous young turtles far off the Southern California Coast provides new insight into their their epic migration across the Pacific Ocean.

The discovery of numerous juvenile loggerhead turtles by a NOAA Fisheries research survey more than 200 miles off the Southern California Coast has revealed new details about a mysterious part of the endangered turtles’ epic migration across the Pacific Ocean known as “the lost years.”

“It’s one of those great ‘aha’ moments in science,” said Scott Benson, a marine ecologist with NOAA Fisheries’ Southwest Fisheries Science Center. “We’ve always known they were out there somewhere, we just didn’t know where.”

North Pacific loggerhead turtles nest on beaches in Japan and young turtles then disappear into the North Pacific, with many reappearing later in a rich foraging area about 6,000 miles away off Baja California. How they get there and what they do along the way has remained largely a mystery, leading biologists to call the little-known chapter in loggerhead lives as “the lost years.”

Late last year a NOAA Fisheries marine mammal survey crisscrossing waters off the West Coast happened onto a striking concentration of what biologists believe were lost-year loggerheads about 200 to 250 miles off Southern California. Within several days researchers spotted more than 70 confirmed or likely young loggerhead turtles less than 20 inches long, about the size of a laptop computer.

Research informs turtle protections

“It’s like a missing piece of the puzzle we just finally got on the board,” said Jeffrey Seminoff, a marine ecologist who leads the Marine Turtle Ecology and Assessment Program at the SWFSC in La Jolla, Calif. “This is the first time we’ve encountered an aggregation of these lost-year turtles far offshore of California. It looks like a very important area for turtles that have just crossed the Pacific.”

How loggerheads cross the Pacific is important because they can get entangled and killed in certain kinds of fishing nets. Improved information about their route and timing can help NOAA Fisheries manage West Coast fisheries to better protect the endangered turtles.

“If we can predict where loggerheads are going to be and when, we can tell where it’s safer to fish,” Seminoff said. “This is a big step forward in terms of being able to do that.”

Biologists have long known that loggerheads are associated with warm ocean water and sightings off California are not unusual, albeit still rare, when offshore waters turn warm, as they have in the last several months.

One theory was that turtles feeding off southern Baja ventured hundreds of miles north toward California during warm conditions.

Juvenile turtles heading south

But the mass of young turtles spotted by the NOAA Fisheries survey appear to have been headed in the opposite direction. They were much smaller and therefore younger than turtles commonly seen off Baja, and were farther offshore than typical loggerhead sightings. That indicates they were still actively migrating south toward Mexico, following currents that carry them from Japan like a giant conveyor belt across the North Pacific and then south along the West Coast.

“Our hypothesis has shifted now,” Seminoff said. “These turtles off California appear to be using it as a transition area on their way to Baja. The pieces fit. They really fit.”

Researchers documented the juvenile turtles along temperature margins where warm eddies swirl up against colder waters, creating unusually productive zones rich in food. Similar temperature features probably occur in the eastern Pacific every year and provide migrating turtles the food they need for rapid growth early in their lives, scientists said.

“These turtles were right on the edges of these features,” Seminoff said. “We now believe these aggregations of turtles probably occur every year when and where the warm eddy features appear, but perhaps only rarely in California waters. Either way, we just have never such an aggregation before. This is one of the best discoveries we’ve had in years in terms of understanding the lives of these turtles.”

Satellite tracking of loggerhead turtles in the Atlantic Ocean recently revealed that juvenile turtles hatched on the beaches of Florida venture thousands of miles east into the open ocean, spending their “lost years” feeding amid floating sargasso beds before returning to nest. NOAA Fisheries scientists are now planning similar tracking of the newfound Pacific loggerhead turtles off California to more completely chart their migration route.

“It’s a similar life history pattern,” Seminoff said. “We’re full steam ahead to find out more.”

Earth’s Magnetic Field Draws Sea Turtles to Their Nests. Loggerhead turtles remember the magnetic fingerprint of the beach where they were born: here.