Our Galapagos Blog
Discovering a subfossil of Darwin’s lost land iguana in the Galapagos Islands
Posted on February 12, 2012 – DARWIN DAY – HAPPY BIRTHDAY CHARLES DARWIN
It has been 177 years since Charles Darwin’s historic visit to the Galapagos Islands. Considering the paramount importance of this visit in his conversion to evolution it may come as a surprise that Darwin spent only 19 days on shore and visited only four islands. He spent about half of this time on just one island; James now known as Santiago, where he found land iguanas in abundance. “I cannot give a more forcible proof of their numbers, than by stating, that when we were left at James Island, we could not for some time find a spot free from their burrows, on which to pitch our tent.”
Darwin was not the first Galapagos visitor to record seeing land iguanas on James Island – James Colnett (1793-94) and David Porter (1813) preceded him – but as far as it is known he was the last. When scientist Louis Agassiz visited the island in 1872 he could not find a single individual in James Bay. (For more on Darwin and Galapagos see Darwin in Galapagos; Footsteps to a New World by K. Thalia Grant & Gregory B. Estes)
Today land iguanas are gone on James Island due to human impact. Darwin said, “The meat of these animals when cooked is white, and by those whose stomachs rise above all prejudices, it is relished as very good food.” Other causes of their disappearance have been habitat destruction and predation from introduced mammals (goats, pigs, rats and donkeys). The good news is that most introduced mammals are now gone on James through the efforts of the Galapagos National Park Service. The habitat is being restored and there are discussions on reintroducing land iguanas to the island.
In 1996, using Darwin’s original manuscripts from the Darwin Archive in the University of Cambridge we retraced Darwin’s steps in the islands and discovered a subfossil tortoise egg at Buccaneer Cove on James Island. There are no historical records of tortoises from this part of the island although early mariners in search of water and food frequented Buccaneer Cove.
In 2011 we returned to Buccaneer Cove to search for more subfossil eggs. Over a period of several hours we were amazed to find over forty nests each with about four subfossil eggs indicating that this was a principal nesting ground for tortoises. This may explain why this was such a popular spot for early mariners. It was while searching for these eggs that we made an even more astonishing discovery; the remains of one of the lost James Island land iguanas.
When we first found the pelvis protruding out of the volcanic ash we suspected it was land iguana. Our excitement with this find was that, if proven to be land iguana, this would represent the first confirmed specimen of land iguana from James Island. The only other known specimens of land iguana from James Island are from HMS Beagle’s visit, one from Darwin’s collection and one from captain FitzRoy’s collection. There is however some uncertainty as to the provenance of these specimens as Darwin and FitzRoy first mentioned seeing land iguanas on Albemarle (Isabela) Island. In his diary for October 1, 1835 after visiting Albemarle Island Darwin said, “They are hideous animals; but are considered good food: this day forty were collected.”
We are pleased to announce today on Darwin’s birthday that it has been confirmed that our specimen is indeed a land iguana. We hope that this specimen may be used to help determine this land iguana’s phylogenetic relationship with others found in the islands and contribute to studies to find James Island’s closest relative which may factor in restoring James Island’s ecosystem.
Book signing at Casper, Wyoming on November 14, 2011
Posted on November 23, 2011
Greg was at Casper College on Monday, Nov. 14 to speak on “Darwin and Galapagos.” The presentation followed the unveiling of the U.S. National Library of Medicine National Institutes of Health Darwin exhibit: Rewriting the Book of Nature: Charles Darwin and the Rise of Evolutionary Theory. Greg signed copies of Darwin in Galapagos: Footsteps to a New World before his presentation in the Roberts Commons Ballroom at Casper College.
Posted by K. Thalia Grant
midday, March 12, 2011
Galapagos Tsunami 2011 update
This tsunami was considerably more intense than the tsunami experienced in Galapagos in 2010. More reports of damage in Puerto Ayora are coming in. The Charles Darwin Research Station suffered severe damage to the labs of the Biomar building. Scuba Iguana, Red Mangrove Hotel, Banco Pacifico, Hotel Finch Bay, and the Parque San Franciso have also experienced significant damage to their lower floors, with some lobbies being filled with over a meter of water. The board walk behind Playa Alemanes was completely ripped out. A lot of debris covers the streets and properties close to the shore but clean up efforts have begun. Electicity has been returned to at least some parts of Puerto Ayora.
Posted by K. Thalia Grant
morning, March 12, 2011
Tsunami generated by massive 8.9 earthquake in Japan causes damage in Galapagos
Yesterday, at 6:38 pm local time, a tsunami wave that was generated by an earthquake off the coast of Japan, hit the town of Puerto Ayora, Santa Cruz Island. The wave was 5.8 feet (1.8 meters). Early reports indicated no damage to the coastal areas of Galapagos, however the reports were issued at the time the wave was anticipated (5:38 pm), which was before it actually struck. The tsunami arrived one hour later, at high tide, and caused damage to some buildings close to the shore. Some hotels, shops, restaurants , houses and office buildings experienced flooding (up to shoulder height in some cases), broken windows and some structural damage. No one was hurt as people had been evacuated to the highlands of Santa Cruz hours earlier. The electricity to Puerto Ayora had also been shut off as a precaution. All boats had left the harbors and bays of Galapagos, and visiting sites were closed down for the day.
Greg, reporting from a tour yacht off Seymour Island, said that all afternoon visits had been cancelled well in advance of the wave, and that all boats were safely off shore. Nobody on board could feel the wave. The wave that hit Baltra Island was smaller; 2.7 feet (0.8 meters).
Flights in and out of Galapagos were cancelled yesterday but have resumed today. Tourism activities are back to normal, although power remains off in Puerto Ayora.
There have been reports of damage to the water front of Puerto Baquerizo Moreno on San Cristobal Island.
I shall be updating this blog as I receive more information.
Darwin’s birthday celebrations at the Vancouver Beaty Biodiversity Museum
Posted on February 12, 2011
Check out this Princeton Darwin Day blog for an interview with Thalia Grant and Greg Estes about their research on Darwin in Galapagos.
A great time for for observing marine iguanas and land iguanas.
Posted on December 23, 2010 by Greg Estes
Marine iguanas are coming into the mating season. Males are displaying and can be seen fighting over territories and access to females. Good places to observe this behaviour include Punta Espinosa (Fernandina Island), Puerto Egas (Santiago Island) and Punta Suarez (Española Island). In Puerto Ayora (Santa Cruz Island) big male iguanas can be seen swimming across Academy Bay searching for territories. Marine iguanas are doing particularly well this year with the Niña conditions (see Island Update). There is plenty of food available. Marine iguanas are especially fond of Ulva, a marine alga often referred to as sea lettuce. Normally the sea lettuce forms a short growing matt of seaweed on the intertidal lava but this year, with the cool nutrient rich waters in the Galapagos, one can see long green fleshy fronds along the shoreline at low tide. From December through February the Española iguanas are particularly colourful when they take on the Christmas colors of red and green. It is not clear why the iguanas are red on Española. One explanation is that the color is related to the iguana’s diet of red algae which is abundant around Española.
December and January is a good time for land iguanas. The Opuntia prickly pear cactus is coming into flower and this is one of the land iguana’s favourite foods. They also feed on the fruits and pads of the cactus. Land iguanas generally don’t like eating cactus spines. Using their front feet they can be seen removing the spines from the pads and fruits before ingesting the cactus. A good place to observe this behaviour is South Plaza Island. During the rainy season which begins in January the island of South Plaza starts to change color. The red succulent ground cover called Sesuvium begins to change from red to green and the Portulaca comes into leaf and flower. The land iguanas have a preference for yellow as they feed on the yellow flowers of Opuntia, Portulaca and Cordia. I have seen people wearing yellow socks or shoelaces being followed down the trail by land iguanas on South Plaza. A good place to observe land iguanas feeding on the yellow Cordia is Urvina Bay on Isabela Island. The iguanas don’t just feed on the flowers of the Cordia but also like the sticky white berries. They also like the apple-like fruit of Manzanillo which is poisonous to humans. Land iguanas may have a tough time this year due to the dry conditions associated with La Niña (see Island Update). A drought is expected for at least the next few months. As a result the land plants which the land iguanas depend on may be scarce. Yesterday, December 22, 2010, while visiting North Seymour Island I observed land iguanas feeding on seaside heliotrope and saltbush.
South Plaza is one place in the islands where hybrid land/marine iguanas can be observed. It is somewhat surprising to come across this hybrid as the land iguana and marine iguana are not just distinct species but also different genera (the genus of land iguana is Conolophus and the genus of marine iguana is Amblyrhynchus). Both of these genera are endemic found only in the Galapagos Islands. The first time I became aware of the hybrids was back in the 1980’s when I observed a male marine iguana mating with a female iguana. I thought I had made a discovery until I talked to a biologist who had researched these animals and told me that hybrids do exist on the island. The reason they are so rare is that there are few places in the Galapagos where the territories and mating seasons of the land and marine iguanas overlap. If you visit South Plaza keep a look out for a hybrid. They look intermediate between the land iguana and marine iguana with distinctive bars running down the sides of their bodies.
Check out our Blog Archive by Greg Estes & Thalia Grant