Handout picture released on October 21, 2015 by the Direccion Parque Nacional Galapagos press office shows the recently discovered 'Chelonoidis donfaustoi' turtle on Santa Cruz island in the Galapagos on August 30, 2015 (AFP Photo/) More Quito (AFP) - A team of Ecuadoran and international scientists said Wednesday they have identified a new giant tortoise species on the Galapagos Islands. There are only a few hundred members of the new species, Ecuador's environment ministry said in a statement. Experts had long believed that the two giant tortoise populations on the Santa Cruz island were of the same species, but genetic tests have shown that those living on the eastern side of the island are different, the statement read. The researchers, led by Gisella Caccone from Yale University, baptized the new species "Chelonoidis donfaustoi," in honor of Fausto Llerena, the caretaker of Lonesome George, a male Pinta Island tortoise and the last known survivor of his species. "We estimate that there are 250 or 300 creatures of this species," Ecuadoran scientist Washington Tapia, who participated in the research, told AFP. Research began in 2002 when two scientists thought that "due to the formation of the shell, these tortoises should belong to a different species." Then, Tapia said, scientists analyzed genetic samples taken from the animals. "In 2005 the preliminary results already suggested that we were dealing with a different species," Tapia said. The shell is indeed different from other tortoises, but "the main difference is at the genetic level," he said. The head of the Galapagos National Park, Alejandra Ordonez, said that research on the new species continues "to determine their exact distribution on the island, their nesting areas, and potential threats." With this find, experts now believe that 15 species of tortoise lived on the islands, including four that are extinct. The Galapagos archipelago, located 1,000 kilometers (620 miles) west of Ecuador, is a fragile ecosystem that harbors the largest number of different animal species on the planet. In 1979 the Natural Reserve became UNESCO's first World Heritage Site.
But global warming is killing off their food and changing their age-old migratory routes. To the tourists watching a humpback whale frolic with her newborn calf in the tropical waters off Ecuador's coast near Puerto Lopez, the sight of enormous fins surfacing, tails flipping and blowholes spouting is breathtaking. The same scenes can be found up and down the South American coast, from Puerto Piramides in Argentina to Cabo Blanco in Peru and Bahia Malaga in Colombia. But to marine biologists, these huge mammals are not as carefree and healthy as they appear. They are skinny, covered in parasites and exhausted from the increasingly long journeys they are making to reproduce. "You can see their bones. They're sick. They have parasites. We never used to see that," said Ecuadorian marine biologist Cristina Castro as she scanned the horizon for more humpback whales, the species she has studied for the past 18 years. These whales swim thousands of kilometers (miles) each year from Antarctica to the waters around the equator to have their young, which measure three to 4.5 meters (10 to 15 feet) at birth and can weigh up to one tonne. But as ocean temperatures rise, whales are migrating earlier and traveling farther. Warmer waters are killing off the supply of krill, the small crustaceans that are whales' main food source in their Arctic feeding grounds. The whales eat several tonnes a day to fatten up for their journeys. Rising temperatures also trick the whales' biological clocks into thinking it is time to migrate. "They are changing their migration cycles. They used to arrive here in July. Now we see them in May," said Castro. Whales are also continuing north beyond the equator, as far as Costa Rica—a behavior never seen before, she told AFP. The International Whaling Commission estimates there were 8,000 to 10,000 humpback whales this year in the Pacific breeding grounds, which stretch from Peru to Costa Rica. Roger Payne, the American scientist who brought humpback whales' songs to world attention in the 1970s, said whales are also threatened by the acidification of the oceans caused by rising concentrations of carbon dioxide in the water. Forty-five years of research off Argentina have shown that this and other effects of climate change are killing off whales' food, he said. "The females will give birth only when the conditions to feed their young are favorable," Payne told AFP. "Nothing is nearly as important as the threat that we get from that effect." When there are less krill in Antarctica, birth rates drop at the equator, and calves tend to have a worse survival rate. "Everything is linked," said Payne's Argentine colleague Mariano Sironi, a specialist in southern right whales. In the latest alarming news, researchers said Tuesday at least 337 dead whales have been found washed up in a remote inlet in Patagonia in southern Chile—one of the largest die-offs on record. "It was an apocalyptic sight," said Vreni Haussermann, one of the scientists who made the discovery on a flyover in June. It is not known what killed the whales, or if the event was linked to climate change. The cyclical warming of the central Pacific—the El Nino phenomenon—is making matters worse and is a harbinger of the dangers to come, researchers said. El Nino has already caused havoc in the Galapagos Islands off Ecuador, a biodiverse paradise where the weather pattern is blamed for the disappearance of 90 percent of marine iguanas, 50 percent of southern sea lions, 75 percent of penguins and nearly all Galapagos fur seals under three years old. "Unfortunately we expect the effects of global climate change to largely reflect those of El Nino," the Galapagos National Park warned recently. The park has a massive marine reserve that draws humpback whales, orca, pilot whales, Bryde's whales and blue whales. Researchers are particularly concerned about blue whales, the world's largest animals, which "show no signs of population increase," said Barbara Galletti, head of the Whale Conservation Center in Chile. Whales of all species are also under threat from other human activity, such as collisions with ships and disorientation caused by noise at sea that interferes with their communications. However, an international moratorium has protected them from hunting since 1986. They have meanwhile become major tourist attractions in many countries along their route. Their survival is fundamental for the health of the world's oceans. Whale feces contain large amounts of iron that feed the growth of microscopic algae that are essential to the marine food chain. "That is the feature which keeps the rest of the ocean alive," said Payne.
News Article | March 24, 2016
Ecuador has announced the creation of a marine sanctuary around Galapagos Islands, protecting the world's largest population of sharks. The Galapagos Islands' northern area of Darwin and Wolf, which covers 15,000 square miles of water, will be a no-take zone. Fishing and taking any of the natural resources are prohibited, a measure that supports an ecosystem that had long been receiving inadequate protection against threats such as overfishing. It has been 19 years since the onset of the Galapagos Marine Reserve on the island, which spans more than 50,000 square miles of water. Even though industrial fishing has been banned within the island, small scale fishing is still allowed within the area. But with this new marine reserve, there will be specifically designated areas that will be a no-take zone, which means fishing will be prohibited completely. Darwin and Wolf, along with several smaller portions of the islands, will be open for tourism and scientific expeditions. The government is urged to increase the islands' protection to preserve the natural habitat from global warming and illegal shark fin hunting. Pelayo Salinas de Leon, senior marine scientist of the Charles Darwin Foundation, said that this is probably one of the "most spectacular and significant marine ecosystems that we have on the planet." His group was also the one that conducted the study in the region in 2013 and 2014. They hired expert divers and made use of cameras to record the number and types of marine species in the reefs surrounding Darwin and Wolf. In that study, Pelayo and his team found the largest biomass of reef fish, most of which were sharks. According to Salinas, the sharks' abundant population within the island has been protected by the Marine Reserve but, due to poaching, the population has been threatened. "The shark populations are still the most abundant on the planet, but the scientific studies show that the abundance of sharks has been declining over time," said Enric Sala of National Geographic, one of the authors of the study. He also added that there will be heightened surveillance over Darwin and Wolf to protect the islands from illegal fishing. Sala and Salinas have added that preserving and protecting fish, especially sharks, will benefit not only the ecosystem but also the economy. In the Galapagos National Park 2015 report, it showed that extreme shark value to tourism outweighs the income-generating capability of the fishing industry. People from all over the world travel to Galapagos Islands just to visit, dive, and see the sharks and other marine animals. Sala met with President Rafael Correa of Ecuador to discuss matters of conservation and protection in the region, as well as the rezoning of the marine reserve protecting the islands. Their discussions have culminated in the announcement of the new marine reserve in the Galapagos Islands. There have been other announcements of marine protection globally in the past. In 2014, U.S. President Barack Obama increased the coverage of marine sanctuary in Pacific Remote Islands Marine National Monument. Chile has also created the Nazca-Desventuradas Marine Park.
Diego, a Galapagos giant tortoise, has fathered an estimated 800 offspring, almost single-handedly rebuilding the species' population on their native island, Espanola, the southernmost in the Galapagos Archipelago. "He's a very sexually active male reproducer. He's contributed enormously to repopulating the island," said Washington Tapia, a tortoise preservation specialist at Galapagos National Park. Diego is a Chelonoidis hoodensis, a species found in the wild only on Espanola. The island is one of the oldest in the Galapagos, the Pacific archipelago made famous by Charles Darwin's studies of its breathtaking biodiversity. Around 50 years ago, there were only two males and 12 females of Diego's species alive on Espanola, and they were too spread out to reproduce. He has done more than any other tortoise to turn that around—with the help of his mates, of course. Diego lives at a tortoise breeding center on Santa Cruz Island, one of the largest in the Galapagos. He is the dominant male of the three assigned to repopulate Espanola. He shares his enclosure with six females, his partners in the task of saving their species. Tough work, but some tortoise has to do it. On a cloudy morning with chilly wind, Diego timidly peeks his head out from his thick shell, then slowly plods toward some leaves for breakfast. "Look, look! He came out. How pretty," said a young girl as she looked on. Diego weighs about 80 kilograms (175 pounds), is nearly 90 centimeters (35 inches) long and 1.5 meters (five feet) tall if he really stretches his legs and neck. He has a mysterious, globe-trotting background to go with his reputation as a Casanova. Diego was found at the San Diego Zoo—hence his name—after Chelonoidis hoodensis was identified as a species and an international campaign was launched to find more of the rare tortoises. "We don't know exactly how or when he arrived in the United States. He must have been taken from Espanola sometime between 1900 and 1959 by a scientific expedition," said Tapia. After being located at the zoo in California, Diego was brought back to the Galapagos in 1976 and put in the captive breeding program. Little did scientists realize just how effective he was, until six years ago. "We did a genetic study and we discovered that he was the father of nearly 40 percent of the offspring released into the wild on Espanola," Tapia told AFP. In all, around 2,000 tortoises have been released on the small island. Thanks to the program, the species is no longer facing extinction. "I wouldn't say (the species) is in perfect health, because historical records show there probably used to be more than 5,000 tortoises on the island. But it's a population that's in pretty good shape—and growing, which is the most important," said Tapia. Of the 15 species of giant tortoise known to have originated in the Galapagos, three have gone extinct—victims of 18th-century pirates who plundered the islands' fragile ecosystem. Diego's species has also been introduced on the island of Santa Fe, where a genetically similar one, Chelonoidis spp, disappeared more than 150 years ago. Not all critically endangered tortoises rise to the challenge as Diego has. Hopes for another threatened species, Chelonoidis abingdoni, faded when its last known survivor died in 2012 at more than 100 years old. Known as Lonesome George, he had refused for years to breed in captivity. Explore further: Effort to revive Galapagos tortoises once thought extinct
Blake S.,Max Planck Institute for Ornithology (Radolfzell) |
Blake S.,University of Missouri-St. Louis |
Blake S.,New York University |
Blake S.,Washington University in St. Louis |
And 6 more authors.
Journal of Animal Ecology | Year: 2013
Seasonal migration has evolved in many taxa as a response to predictable spatial and temporal variation in the environment. Individual traits, physiology and social state interact with environmental factors to increase the complexity of migratory systems. Despite a huge body of research, the ultimate causes of migration remain unclear. A relatively simple, tractable system - giant tortoises on Santa Cruz Island, Galapagos, was studied to elucidate the roles of environmental variation and individual traits in a partial migratory system. Specifically, we asked: (i) do Galapagos tortoises undergo long-distance seasonal migrations? (ii) is tortoise migration ultimately driven by gradients in forage quality or temperature; and (iii) how do sex and body size influence migration patterns? We recorded the daily locations of 17 GPS-tagged tortoises and walked a monthly survey along the altitudinal gradient to characterize the movements and distribution of tortoises of different sizes and sexes. Monthly temperature and rainfall data were obtained from weather stations deployed at various altitudes, and the Normalized Difference Vegetation Index was used as a proxy for forage quality. Analyses using net displacement or daily movement characteristics did not agree on assigning individuals as either migratory or non-migratory; however, both methods suggested that some individuals were migratory. Adult tortoises of both sexes move up and down an altitudinal gradient in response to changes in vegetation dynamics, not temperature. The largest tagged individuals all moved, whereas only some mid-sized individuals moved, and the smallest individuals never left lowland areas. The timing of movements varied with body size: large individuals moved upward (as lowland forage quality declined) earlier in the year than did mid-sized individuals, while the timing of downward movements was unrelated to body size and occurred as lowland vegetation productivity peaked. Giant tortoises are unlikely candidates for forage-driven migration as they are well buffered against environmental fluctuations by large body size and a slow metabolism. Notably the largest, and presumably most dominant, individuals were most likely to migrate. This characteristic and the lack of sex-based differences in movement behaviour distinguish Galapagos tortoise movement from previously described partial migratory systems. © 2012 The Authors. Journal of Animal Ecology © 2012 British Ecological Society. Source