February 6, 2012 § 1 Comment
After finding the descendants of a species of giant tortoises believed extinct from the Galapagos Islands for 150 years, Yale researchers are hoping to save the species.
In an expedition to Isabela Island led by Adalgisa Caccone GRD ’86, senior research scientist in ecology and evolutionary biology, the researchers found 84 tortoises whose genes show that one of their parents is a member of the supposedly extinct species, C. elephantopus. Published Jan. 9 in the journal “Current Biology,” the subsequent report stated that at least 38 purebred individuals of that species are still alive, and Caccone said she hopes to return to the Galapagos to find them.
“We can bring back a species from near extinction,” said Caccone. “If we can find these individuals in a larger expedition, we can return the species to its [original state] and reestablish the ecological equilibrium.”
Thirty of the turtle descendants were younger than 15 years old, and since giant tortoises often live over 100 years, this data suggests some parents are still alive. Carefully breeding the hybrids may also allow scientists to revive the C. elephantopus species even if the purebreds cannot be found, Caccone added.
The study claimed to be the first to rediscover a supposedly extinct species by analyzing the DNA of its offspring, though Caccone said in an interview with the News that her team simply applied standard analytical techniques.
“We had access to a large database that included the genetic fingerprints of [diverse giant tortoise] species, including extinct data,” Caccone said. “It was a huge effort, and a lot of undergraduates helped us with the project [to analyze all the samples].”
The team accumulated blood samples from over 1,600 tortoises, around 20 percent of the total tortoise population on Isabela Island, and compared the DNA to a genetic database of tortoise species. They found close correlations to the extinct species, identifying 84 direct descendants.
When Charles Darwin explored the islands in 1835, he found fifteen species of giant tortoises. Since only eleven species remain in the Galapagos today, Caccone said it is important to halt this rapid extinction. The differentiation Darwin saw between similar species on different islands, such as finches, was crucial in the development of his theory of evolution.
The giant tortoise is the only grazing herbivore native to the Galapagos, and plays an important ecological role, Caccone said, by helping to keep vegetative growth in check. On some islands where tortoise populations have dwindled, invasive plants and overgrowth have become a problem, she said.
On Floreana, the “extinct” species’ native island, the ecosystem is out of equilibrium. Caccone speculated that the tortoise was likely transported to Isabela aboard a ship as food, and then left on the island. Meanwhile the population on Floreana was wiped out due to hunting by whalers, pirates and local workers during the 19th Century.
University of British Columbia biology Professor Michael Russello, who contributed to the study, said he looks forward to a future expedition to the Galapagos that will allow conservationists to establish a breeding program and restore the species to Floreana.
“The return of tortoises to Floreana would [help] to restore the native flora and fauna of the island,” Russello said.
George Amato GRD ’94, director of the Sackler Institute for Comparative Genomics at the American Museum of Natural History, called the study “exciting” and “very significant.” He added that he is optimistic about the likelihood of finding the parents and hopeful about seeing the research translate into measurable conservation initiatives.
Even if purebred members of C. elephantopus cannot be found, Russello and Amato said the 84 offspring found may cumulatively have enough genetic variation to design a breeding program that would revive the species.
Ths project could provide a case study of how to restore extinct species from their close descendants.
“Success with this one species will give hope and a practical example for future conservation efforts, maintaining public interest in conservation that is essential for [receiving] funding and [influencing] political or community organizations,” said Brittney Kajdacsi ’11, a lab assistant to Caccone.
The giant tortoise is among the largest reptiles and longest-living animals on Earth, thought to have arrived on the Galapagos Islands from Ecuador about 1 million years ago.
For more on this topic read our Blog The Evolution of Extinction
January 2, 2012 § Leave a comment
The story of the Baltra Land Iguanas is one that illustrates the effect both good and bad humans have had on the Galapagos wildlife population over the years.
Up until the early part of the 20th century Baltra was considered “Iguana Headquarters”. There were hundreds of land iguanas living on the island of Baltra. Located near the center of the Galapagos Islands just north of Santa Cruz Island, Baltra is a small and relatively flat island with little vegetation other than the prickly pear cactus, a staple in the land iguana diet.
In the early 1930’s the Hancock-Pacific Galapagos Expedition made several voyages to the Galapagos. Funded by Allan Hancock a renaissance man of the time. Hancock was considered a sea captain, oilman, explorer, developer, banker, aviator, scientist, businessman, farmer, railroad engineer, musician and philanthropist. More over Hancock was a man of great wealth and connections. For his expeditions to the Galapagos Hancock put together a group of experts including Waldo Schmitt (of the Smithsonian Institution) who would also accompany FDR during his 1938 fishing trip to Galapagos.
During their voyages the Hancock Expedition collected and cataloged a number of new species of wildlife from the Galapagos. These species were subsequently brought back to the United States and donated to some of the country’s finest institutions including the Smithsonian Museum, the California Academy of Sciences, the San Diego Zoological Gardens, and the Steinhart Aquarium.
In January 1934 the Hancock Expedition visited Baltra Island. While there the expedition collected approximately 15 land iguanas to be transported back for the San Diego Zoo. During the time on the island, several scientists noticed that many of the land iguanas seemed to be suffering from starvation.
Two days later the Expedition visited North Seymour. North Seymour and Baltra (South Seymour) are located relatively close together and the conditions on both islands are similar. However the expedition members noted North Seymour had more vegetation and therefore they felt it was a more favorable environment for the iguanas. Not seeing any reason why North Seymour did not have its own population of land iguanas, the group decided to help save the starving iguanas.
They returned to Baltra to capture additional iguanas and relocated them to North Seymour. Normally this would be considered a disastrous event as land iguanas were not native to North Seymour and thus became an introduced species to the island. As with any introduced species it has the potential to change the natural habitat and affect the flora and fauna naturally found on the island. Over time the actions of the Hancock Expedition would prove to be quite fortunate.
By the end of the 1930’s hostilities grew all over the world and World War II would begin. In 1943 a military base was established in Baltra. Shortly after the end of the war land iguanas became extinct on that island. The reason for the extinction has been speculated for many years. Early history books and many in Galapagos have blamed the military personnel stationed on Baltra for killing the iguanas for sport. That these same military people through deliberate acts would led to the extinction of the Baltra Iguanas.
According to John Peck who was stationed with the Navy on Baltra during WWII “We could have free range of the Navy side and we could explore the area, but could not to molest the wildlife”.
Records show there were orders that came down from the military according to Wetmore’s memorandum of December 9, 1942 “you take appropriate action to prevent any unnecessary molestation of the wildlife in the Galapagos Archipelago and to prohibit the introduction of domestic animals that prey on the native fauna”
It seems highly unlikely that a group of young men under direct orders not to harm the native wildlife would be shooting the iguanas for fun.
Taking this into consideration leaves a mystery as to why would an island, which was considered “Iguana Headquarters” in the early 1930’s see the Iguana become extinct in a period of 20 years.
At a reunion of the 29th Bombardment Squadron in 1989 a small survey was taken regarding the iguanas. “Do you have any first or second hand accounts of hunting iguanas or eating them?” The respondents unanimous stated “NO”.
John Peck describes, “We had a pet iguanas called IT as the sex was unknown. It would sleep on the table in the medical laboratory, the medical techs would feed it vegetables greens i.e. lettuce and carrot tops. IT was very gentle and enjoyed all the care given to the animal. We would take IT to other places on the base and many of the personnel would pet and feed IT.”
It seems that from what John Peck has stated and the survey of the 29th Bombardment Squadron that the military personnel were not killing iguanas. As a group they seemed genuinely found of the iguanas and made many of the iguanas into pets.
The theory that the military personnel were responsible for the decline of the Baltra iguana population through a deliberate act seems unlikely. By doing some research of the events of the events over these years there seems a more likely scenario for what actually occurred.
As we mentioned in an earlier blog the first military personnel were sent to Baltra less than a week after the attack on Pearl Harbor. Construction of the base was in effect in March 1943. Military documents from the SeaBees (the construction battalion who built navy bases all over the world) show it was Ecuadorian contractors who began the construction of the Baltra Base in the early portion of 1943. These contractors used local sand and loose soil in the construction of the concrete they used to pour the foundations of buildings, the dock and airport. When the SeaBee’s arrived in Baltra in October of 1943 to complete the job and imported all materials needed to finish the construction and used no native materials in their building of the base.
Early military correspondence regarding the base includes a report from Wetmore in 1942. “We have report of native laborers engaged in various work on the islands killing iguanas for their skins. This was stop by one of the officers but may begin again at any time”
While the native labors seem to have been deliberately killing land iguanas for their skins it was the Ecuadorian Contractors unintentional acts that proved far more costly to the iguanas.
In the 2989 survey of the 29th squadron members were asked “Do you have any recollection of the iguana population when you arrived? When you left? While you where there did the population increase/decrease/remain stable? Did you see any young iguanas?”
All of the respondents stated they remember iguanas when they arrived, while they were there, and when they left. However none remembered ever seeing any young iguanas. Why suddenly on an island with a healthy iguana population would suddenly there be no baby iguanas?
Iguanas lay their eggs in sand or loose soils, the same materials that the local contractors excavated to build the new base. In using the local sands and loose soils the early contractors would have upset the iguana nesting sites and in affect caused the population of young iguanas to decline.
When combining the decline in new iguanas with other factor from the time the reason for extinction of the Baltra Iguanas seems quite clear. For much of the 1940’s the US military occupied Baltra. During this time iguanas and goats were both left to have free range of the island.
The earlier instruction to rid the islands of introduced domestic animals seemed to reach the Galapagos as not to bother any of the animals as evident from a memorandum from Harmon in 1946
“The large number of native goats, protected by Executive Order, make a continuous practice of upsetting garbage and trash cans. They are a great annoyance and menace to sanction. Initiate request… for authority to round them up and transport them either to Little Seymour (Seymour North) or to Santa Cruz”
The US Military left Baltra in 1948 and five years later in 1953 land iguanas were extinct on Baltra. Why did the Baltra Land Iguanas become extinct?
It was not because the military personnel were not shooting the iguanas for sport or eating the iguanas.
The reason for the extinction is early contractors upset the nesting grounds and no new iguanas were born. The number of plants available as food for the iguanas was scarce at the time of the Hancock Expedition in the 1930’s and when the population of goats was allowed to grow the competition for food may have put further stain on the scarce food supply. When competing for food between goats and iguanas the goats always win.
Lastly as we know from the land iguanas on South Plaza, iguanas can relate people to food and remember this correlation. On Plazas early passengers would bring oranges ashore, quickly the iguanas related visitor to an easy supply. The lazy iguanas began hopping into the laps of visitors begging for food. John Heck told us that the military personnel would feed the iguanas lettuce, carrot tops and other produce causing the iguanas to become accustom to people and relating people to an easy food sources.
As mentioned above the Wetmore memorandum of 1942 native laborers were killing iguanas for the skins. At the time the military left the island the iguanas found on Baltra would have been far easier to capture as they now related people to food so anyone wanting to capture an iguana would find it an easy job.
A combination of these factors would account for what happened to the iguanas. The iguanas disappeared from Baltra as a consequence of the coming into contact with humans. It was ignorance of the consequences of their actions by the people who came into contact with the iguanas led to their deaths rather than any deliberate malicious act.
All of this would be a terribly sad story of a species that is now extinct if it hadn’t been for the decision made by the Hancock-Galapagos Pacific Expedition in January 1934. By moving iguanas to North Seymour on this voyage and the proceeding voyage the members of the Hancock Expedition consequently saved the Baltra Land Iguanas from extinction. In the 1980’s the Galapagos National Park captured iguanas on North Seymour and brought them to the Charles Darwin Research Station where they were bred. In the 1990’s these land iguanas were reintroduced to Baltra the island where they originated. Today while there are no longer goats on Baltra, there is still a military base, an airport and a healthy population of land iguanas.
December 13, 2011 § 1 Comment
December starts the mating season for the Galapagos Green Sea Turtle. A subspecies of the Green Sea Turtles, the Galapagos Green Sea Turtle is the only of its species to nest on the shores of the Galapagos Islands.
Curious creatures, sea turtles are frequently seen bobbing their heads out of the water to see passing boats and are frequently seen watching snorkelers from a safe distance. Surprisingly enough visitors are more likely to encounter sea turtles in Galapagos than they are tortoises. Galapagos Green Sea Turtles unlike the enigmatic Galapagos Tortoise lives in the sea, while the Galapagos Tortoise lives its life on land. Male sea turtles live their entire lives at sea while females come ashore to nest and lay eggs.
At night the female will come ashore and navigate to above the high tide line where it will dig a pit with its back flippers in the loose sand. It will lie normally between 75 to 100 eggs per pit. When she finishes laying the eggs the female will carefully cover the pit with sand and then return to the sea. It takes the female between 3 and 8 hours to complete the process, as she will often dig false pits to fool predators.
During mating season the female will make a nest every couple of weeks laying approximately 600 eggs per season. Unfortunately Galapagos Sea Turtles have a high mortality rate due to egg beetles, crabs, hawks, mockingbirds and frigate birds as well as feral pigs and rats.
November 9, 2011 § 2 Comments
Since the beginning of the 2011 breeding season, scientists from the University of San Francisco de Quito have observed mass mortality of newborn pups, miscarriages and stillbirths on and near San Cristobal Island in the eastern region of the Galapagos Islands.
Mortality rates for pups have reached almost 60% compared with an average of 5 – 15% in a normal year.
The Galapagos National Park (GNP), with help from the Charles Darwin Foundation (CDF), the University of San Francisco / Galapagos Science Center and Agrocalidad are urgently trying to determine the main reason for the deaths.
The need for a quick diagnosis is clear – the Galapagos Sea Lion (Zalophus wollebaeki) is already classed as endangered and the spread of this disease to other islands in the Archipelago carries a serious threat to the species. Although the cause of this mass mortality remains unknown, the clinical signs point to a variety of diseases, some of which may have the potential for transmission to and from other mammals, or possibly even humans.
The scientists at CDF are acting with great urgency together with their partners and have requested the support of the Galapagos Conservation Trust to aid:
- the identification of the disease agent
- the formation of an action plan to contain the disease
- the monitoring of future pup mortality, sample collection and analysis
- the sampling of sea lion colonies on other islands for comparison and to identify the spread of disease
- the protection of public health
- the planning and implementation of health surveillance to identify and mitigate disease threats in the future more rapidly
October 21, 2011 § 2 Comments
One of the largest of flying birds, albatrosses have been described as “the most legendary of all birds”. The Albatross has been the subject of legends and stories for hundreds of years going back to the day of great sailing ships where sailors believed that albatross were the spirits of sailors lost at sea to being the central emblem to the poem “The Rime of the Ancient Mariner”.
The Galapagos Albatross or the Waved Albatross is the only member of the Albatross family that lives in the topics. The Galapagos Albatross is considered endemic to the Island of Española though in recent years small groups have been identified on both on the island of Genovesa and 5 to 6 pairs on Isla de la Plata on the coast of Ecuador. The Albatross arrive on Española each April where they mate, nest and remain through December.
Albatross come back to find the same mate every year until one or the other dies. The mating ritual begins with the couple engaging in a series of beak jousting moves where they circle each other raise and lower and then clack together. They then built a nest typically on the rocky surface. The couple will produce 1 egg per year which is raised in a nursery with other chicks while the parents head out to sea to feed. In December when the chicks are big enough to survive on their own entire colony will head out to sea where they live over the ocean along the coasts of Ecuador and Peru.
Visiting Española you can see the chicks as well as the adults with their giant 6 foot wing span as the fling themselves off the cliff to fish in an area appropriately nicknamed the Albatross Airport.
Andres Baquero, executive director of Equilibrio Azul Foundation, says that a Waved Albatross population is classified as Critically Endangered. The number one threat to the Albatross population is fisherman as the birds confuse the prey on hooks and get caught by fisherman. In a study conducted by the Foundation in Santa Elena, 30% of respondents had seen fishermen albatross their hooks.
“Fishermen are not interested in capturing seabirds in the country, that way no problem,” emphasized Baquero. The sixth meeting of Agreement on the Conservation of Albatrosses and Petrels (ACAP) took place in Guayaquil at the end of August and is looking into new ways to help preserve these majestic birds.
September 30, 2011 § 1 Comment
Red Footed Boobies are the smallest member of the booby family at only about 28 inches in length making them a couple inches smaller than the Blue-Footed and Nazca Boobies also found in the Galapagos Islands.
Telling the difference between these three types of boobies is quite easy as the appearance of all three is quite unique. The blue-footed booby is mainly white with brownish wings and bright blue feet while the Nazca (also known as Masked) booby is white with a black band around its eyes like a mask and pointed black wings. The red-footed booby has a range of color the majority seen in the Galapagos have a brownish body color with a blue and pink face, beak and throat pouch and red feet which give the bird its name.
During mating season hundreds of animals may pair up and mate. Unlike other boobies the red-footed booby build their nests in shrubs or trees. A female will lay an egg every 15 month. Both parents incubate the egg, and brood and feed the chick. The parents continue to feed the young for up to four months after fledging.
Red-footed boobies are excellent fliers and spend most of their long lives (up to 20 years) at sea. They are often seen flying above or along side passing boats. The red-footed booby is semi-nocturnal and can be seen fishing both during the day and for squid at night.
The colorful red-footed boobies are the least seen of the three species of boobies that are found in the Galapagos by visitors. The best way to see them is by taking a Galapagos Cruise that stops at one of their two nesting sites in the islands either at Genovesa or Punta Pitt on the northeastern tip of San Cristobal.
September 29, 2011 § Leave a comment
The Fausto Llerena Breeding Center at the Charles Darwin Research Station has just opened two new pens for small Galapagos Tortoises. The pens approximately 1000 square meters in size will be home to tortoises two years of age who will spend two more years at the center before being released on their home island.
In one pen there are 180 pre juvenile tortoises from the species Geochelone ephippium and Geochelone hoodensis which originate from Pinzon and Española. The second pen houses 117 tortoises (Geochelone darwini) from the Island of Santiago.
While at the breeding center the park rangers care for the tortoises, feeding them twice a week, keeping the pen clean as well as monitoring their growth every three months.
The Charles Darwin Research Station and the Fausto Llerena Breeding Center is located on the island of Santa Cruz and is a frequent stop for visitors of to the Galapagos Islands. The Breeding Center is currently home to 925 young tortoises and 70 adult tortoises including Lonesome George – famous for being the last of the Pinta Tortoises.