The following readings are on the Galapagos Islands, there are no readings about Guayaquil but we will be visiting Guayaquil for about three days, we depart for the Galapagos Islands from Guayaquil.
Map of the Galapagos from Ecotourism
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The Geology of the galapagos islandsThe Galapagos Islands are a chain of volcanic islands about 600 miles west of the coast of Ecuador. The islands are located on the Nazca tectonic plate which is moving east-southeast over the Galapagos hot spot. As the plate moves over the hot spot the chain of islands were created, the islands get older in the direction of plate motion, Espanola is the oldest Galapagos Island. The hotter and less dense rock below the plate rises and the plume melts as it nears the surface due to the decrease in pressure. The magma that is rising to the surface gets trapped in magma chambers and then the magma forces itself to the surface causing a volcanic eruption. After successive eruptions a volcano is produced, magma crystallizes in the chamber
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causing the crust to thicken. The thickening crust and the upward motion of the plumes pushing the lithosphere up made the Galapagos Platform. As the lithosphere carries a volcano away from the magma plume it becomes extinct, as the volcano and lithosphere cools it causes it to contract and sink making seamounts. North of the islands there is a mid-ocean ridge that is offset by fault and fracture zones. Along the west coast of South America there are subduction zones where these old islands are disappearing because of this the age of the Galapagos plume is unknown. (White, 1997).
Galapagos Volcanoes: Each major island is made of one large volcano, except for Isabela which is made of six volcanoes that joined together. (Geologic History) The Galapagos are separated into several subprovinces based on the volcanoes' ages, geomorphic forms and their lavas. The old subprovince is made of Espanola, Santa Fe, Baltra Islands, and the northeast corner of Santa Cruz which are volcanoes that were active 3 to 1 million years ago. The central subprovince is made of San Cristobal, Santa Cruz, and Santiago Island, these volcanoes have shallow slopes and lack a caldera. The western subprovince is made of Isabela, Fernandina Islands, and Roca Redonda volcanoes which are shield volcanoes. Florena does not below to a subprovince, it has a subdued form with late parasitic cones. On the western part of Isabela and Fernandina islands the volcanoes have an inverted soup bowl morphology and deep calderas, in the east they have small shield volcanoes, the two different types of volcanoes is due to the difference in lithospheric thickness. The northern subprovince is made of Wolf, Darwin, Genovesa, Marchena, and Pinta Islands and they are the most diverse petrologically. Marchena and Genovesa have calderas, Wolf may have had one but it is now eroded and the other islands do not have one. (Geist, 2011).
Galapagos Volcanoes: Each major island is made of one large volcano, except for Isabela which is made of six volcanoes that joined together. (Geologic History) The Galapagos are separated into several subprovinces based on the volcanoes' ages, geomorphic forms and their lavas. The old subprovince is made of Espanola, Santa Fe, Baltra Islands, and the northeast corner of Santa Cruz which are volcanoes that were active 3 to 1 million years ago. The central subprovince is made of San Cristobal, Santa Cruz, and Santiago Island, these volcanoes have shallow slopes and lack a caldera. The western subprovince is made of Isabela, Fernandina Islands, and Roca Redonda volcanoes which are shield volcanoes. Florena does not below to a subprovince, it has a subdued form with late parasitic cones. On the western part of Isabela and Fernandina islands the volcanoes have an inverted soup bowl morphology and deep calderas, in the east they have small shield volcanoes, the two different types of volcanoes is due to the difference in lithospheric thickness. The northern subprovince is made of Wolf, Darwin, Genovesa, Marchena, and Pinta Islands and they are the most diverse petrologically. Marchena and Genovesa have calderas, Wolf may have had one but it is now eroded and the other islands do not have one. (Geist, 2011).
Speciecs Arrival on the islands
Marine Iguana from WWF
Plants in the Galapagos from Galapagos Cruises
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About 5 to 10 million years ago the Galapagos volcanoes rose above the water without any life on it. Life could have arrived to the Galapagos by sea, swimmers like sea lions, sea turtles and penguins could have swam there with the help from ocean currents. Many of the reptiles and small mammals could have been carried on rafts of vegetation. This could explain why the diversity on the Galapagos are unbalanced compared to continental diversity, there are many reptile species found on the islands but no amphibians, there are many bird species but few mammals. Reptiles are able to handle harsh conditions of salt and sunny conditions more than amphibians and mammals, reptiles were able to survive the trip to the islands more than amphibians and mammals were able to. Coastal plants have seeds that are salt tolerant so they could have made it to the islands by being transported by the water and currents. Native species also made it to the Galapagos by air, the wind carried seeds of plants, insects and weaker flying birds and bats could have also been blown by the wind. Most sea birds are good flyers so they could have just flown to the islands, many birds probably brought plant seeds over that were attached to the wings or feet or in their stomachs. Once the species arrived on the islands that had to be able to establish themselves and reproduce there. Plants that needed birds and bees to pollinate them likely did not survive, it was easier for animals to survive than plants because they could move to favorable conditions. Today humans introduce new species and most of the time they are harmful to the islands. (Galapagos Conservancy, 2015).
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Protecting the Galapagos From INVASIVEs
Humans have brought species to the islands that do not belong there and they cause devastating damage. During the dry season drip pools provide Galapagos tortoises with water, these drip pools are made from mist coming off of the shoreline onto trees and the mist drips off of the vegetation and creates pools below them. Goats were introduced in the 1500s, the population grew to about two-hundred-fifty thousand goats by the 1990s, these goats ate all the vegetation in their path. The drip pools were not being formed anymore because there was no vegetation for the mist to go on and it damaged the tortoise population. From 2004-2006 Project Isabela was put in place to restore Pinta, Santiago, and Isabela islands. Helicopters would go out with two shooters, they would find packs of goats and would starts shooting them, this eliminated about 90% of the goat population. The goats started to get smart, when they would hear a helicopter coming they would hide, so then they selected a goat, sterilized it, put a radio collar on it and release it back into the population, they were known as the Judas goats. Since goats are gregarious animals they would go back to a group of goats, leading the helicopter to them. They also gave female goats hormones that put them in heat for 180 days, this would attract males to them and would allow the shooter to shoot bigger groups. They continued killing the goats until only the Judas goats were left. The vegetation began growing back again and the drip pools returned. (Radiolab).
In 1906 the Pinta tortoises were thought to be extinct but in 1972 one male, Lonesome George, was found on the island. Scientists wanted to save this species but the only female found on the island was killed by people, they brought females from another island and did everything they could to get them to reproduce. Finally, in 2008 he mated with all the females on the island but every egg was infertile, in 2012 Lonesome George died. Scientists then found a group of tortoises that were not on Pinta but had a lot of Pinta DNA, they probably got to the other island by humans. So if they took the tortoises with the most Pinta DNA than in four generations there will be offspring with 90% Pinta DNA. They also |
Judas Goat from Invasive Animals CRC
Lonesome George from Gray
Medium Tree-Finch from Brinkhuizen
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could bring the Pinta tortoises to the island and allow nature to take over and evolve a new Pinta Tortoise.
Darwin's finches are from the Galapagos and in 1997 nests with dead baby finches with holes in their nostrils were found. The holes were from the larvae of philornis downsi feeding on the blood from these babies. When the birds lay their eggs, the flies lay them in their nests, when the baby finches are born the larvae crawl into their nose. Four different species of finches have 95% of the babies dying in the nests. There are five species facing extinction and six are in a serious decline. Scientists was to release sterilized males but in order for them to be successful they have to be able to raise millions and have only been able to raise three to adulthood. Adult finches are picking the larvae out of the nostrils and are eating them, the babies try to avoid them as best as they can. The large tree finch has found to be extinct, the medium tree finch is on the brink of extinction, and the small tree finch is doing slightly better than the medium. It has been found that the medium and small tree finch have been mating together, this should not be possible because they are two different species. The hybrids have a 15% survival rate and there are less flies in their nests, this could be the beginning of a new species of finches. (Radiolab).
How far should scientists go to save a species? How far should they go to restore a place that has been damage by people to bring it back to its original state? It is always hard to decide how far to go to protect and bring something back to what it was. It is our responsibility to try to right the wrongs we have done, a perfect example of this is Project Isabela, we were responsible for the nonnative goats being introduced to the islands and we took responsibility in ridding the islands of them. It's difficult to decided how we should deal with the Pinta tortoises, if we let nature take over they will adapt and evolve into a new Pinta tortoise or we could get the old Pinta tortoise back by selecting the tortoises with the most Pinta DNA, generation after generation. Sometimes it's best to let nature run its course and the medium and small finch hybrids show this, they are two species that are in great danger of extinction but they are trying to find a way out of it. When it comes to human involvement, I think we should be involved, especially by keeping track of population numbers, we should intervene when we have to, like we did with Lonesome George, although it was not successful this time it does not mean it won't be successful every time. But the best thing to do is let nature take over, it will find a way.
Darwin's finches are from the Galapagos and in 1997 nests with dead baby finches with holes in their nostrils were found. The holes were from the larvae of philornis downsi feeding on the blood from these babies. When the birds lay their eggs, the flies lay them in their nests, when the baby finches are born the larvae crawl into their nose. Four different species of finches have 95% of the babies dying in the nests. There are five species facing extinction and six are in a serious decline. Scientists was to release sterilized males but in order for them to be successful they have to be able to raise millions and have only been able to raise three to adulthood. Adult finches are picking the larvae out of the nostrils and are eating them, the babies try to avoid them as best as they can. The large tree finch has found to be extinct, the medium tree finch is on the brink of extinction, and the small tree finch is doing slightly better than the medium. It has been found that the medium and small tree finch have been mating together, this should not be possible because they are two different species. The hybrids have a 15% survival rate and there are less flies in their nests, this could be the beginning of a new species of finches. (Radiolab).
How far should scientists go to save a species? How far should they go to restore a place that has been damage by people to bring it back to its original state? It is always hard to decide how far to go to protect and bring something back to what it was. It is our responsibility to try to right the wrongs we have done, a perfect example of this is Project Isabela, we were responsible for the nonnative goats being introduced to the islands and we took responsibility in ridding the islands of them. It's difficult to decided how we should deal with the Pinta tortoises, if we let nature take over they will adapt and evolve into a new Pinta tortoise or we could get the old Pinta tortoise back by selecting the tortoises with the most Pinta DNA, generation after generation. Sometimes it's best to let nature run its course and the medium and small finch hybrids show this, they are two species that are in great danger of extinction but they are trying to find a way out of it. When it comes to human involvement, I think we should be involved, especially by keeping track of population numbers, we should intervene when we have to, like we did with Lonesome George, although it was not successful this time it does not mean it won't be successful every time. But the best thing to do is let nature take over, it will find a way.
GALAPAGOS Biodiversity
Land Iguana from Wikipedia
Rice Rat from Cross
Galapagos Sea Lion from Ishpingo
Blue Footed Boobies from Koghul
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About 80% of land birds, 97% of reptiles and land mammals, more than 30% of plant species, and 20% of marine species are endemic to the Galapagos.
Galapagos Tortoise- they are one of only two remaining tortoises in the world, there are two types of morphological forms of their carapace, one is domed and the other is saddle-backed. The domed tortoises are larger and they live on larger, higher islands with humid highlands but the saddle-backed tortoise live on arid islands, both can survive up to a year without food or water. Humans are one of their biggest threat, they exploited them for food and oil, humans also introduced rats and pigs which eat tortoise eggs. Land and Marine Iguanas- there are three species of land iguanas, they live in drier areas and get their water from succulents. They allow Darwin's finches to pick ticks off of them. Feral dogs decimated two populations, also cats fed on younger ones while dogs fed on adults. and the iguanas were saved by removing them from their habitat until the dogs were removed. The marine iguana is the only sea-going lizard in the world, they also get preyed on by cats, some raptors prey on them. El Nino events serve as the biggest threat to the marine iguanas. Galapagos Fur Seal and Sea Lions- the sea lions are the largest animals found there and are more tolerant to heat that fur seals, despite the name "fur seal" they are actually a type of seal. Both species' females only give birth to single pups and they care for them for one to three years but the fur seal will only care for one young at a time. Fur seals were hunted for their coats in the 1800s, almost bringing them to extinction. Rice Rats- only four of the original seven species are still extant today, they live on Santa Fe, Santiago, and Fernandina which are uninhabited by humans. Rice rat species became extinct because when humans inhabited the islands they brought black rats which created competition or carried a virus.They arrived to the islands by vegetation rafts, they hold the world record for terrestrial mammal crossing. Dolphins and Whales- the Bottle-nosed Dolphin and the Common White-bellied Dolphin are found here, the Bottle-nosed Dolphin often race alongside boats. Sperm Whale, Killer Whale, False Killer Whales and the Pilot Whale are found in the Galapagos Marine Reserve. Land Birds- there are 29 species and 22 of them are endemic to the islands, 13 of these endemic species are Darwin's finches. The finches are noted for their different beak sizes and shapes in different species. Owls, mockingbirds, hawks, and doves also inhabit these islands. Sea and Shore Birds- There are 56 species and 45 of them are endemic, they are home to the Galapagos penguin, the only species of penguin that lives above the equator.There are three species of boobies, flightless cormorant, waved albatross, frigate birds, the Galapagos Flamingo, and herons. Humans are the biggest threat to sea and shore birds but their late arrival on these islands has retained many of the native species. The Galapagos have a diverse ecosystem but it is threatened everyday by the human inhabitants. The species that made the Galapagos home are unique and many of them only exist on these islands. It's amazing to see how the species on the Galapagos have evolved away from their continental counterparts. (Galapagos Conservancy, 2015). |
Works Cited
Galapagos Conservancy. (2015). Retrieved from http://www.galapagos.org/
Geist, D., Harpp, K. (2011, July). The Galapagos as a Laboratory for the Earth Sciences. Retrieved from http://www.webpages.uidaho.edu/~dgeist/Chapman/ChapmanFieldTripGuide.pdf
Radiolab. (n.d.). Galapagos. Retrieved from https://www.wnyc.org/radio/#/ondemand/388850
White, W. (1997). A Brief Introduction to the Geology of the Galapagos. Retrieved from http://www.geo.cornell.edu/geology/GalapagosWWW/GalapagosGeology.html
Galapagos Conservancy. (2015). Retrieved from http://www.galapagos.org/
Geist, D., Harpp, K. (2011, July). The Galapagos as a Laboratory for the Earth Sciences. Retrieved from http://www.webpages.uidaho.edu/~dgeist/Chapman/ChapmanFieldTripGuide.pdf
Radiolab. (n.d.). Galapagos. Retrieved from https://www.wnyc.org/radio/#/ondemand/388850
White, W. (1997). A Brief Introduction to the Geology of the Galapagos. Retrieved from http://www.geo.cornell.edu/geology/GalapagosWWW/GalapagosGeology.html
Picture Citations:
Brinkhuizen, D. (2014). Medium Tree-Finch. Retrieved from http://ibc.lynxeds.com/photo/medium-tree-finch-camarhynchus-pauper/female-presumably- species
Cross, J. (2011). Various Critters of the Galapagos. Retrieved from http://www.pbase.com/johncrossphotography/image/139342831
Ecotourism. (n.d.). Galapagos Island Cruises. Retrieved from http://www.ecotourism.ca/galapagosislandcruise.html
Galapagos Cruises. (n.d.). Galapagos Islands. Retrieved from http://www.cruisesingalapagos.com/galapagosislands/
Gray, R. (2012). Lonesome George could be resurrected after cells are frozen by scientists. Retrieved from http://www.telegraph.co.uk/news/earth/wildlife/9468918/Lonesome-George-could-be-resurrected-after-cells-are-frozen-by-scientists.html
Ishpingo Tours. (2015). Galapagos Sea Lion and Pup. Retrieved from http://ishpingotours.com/tours-and-excursions/galapagos-tours-and-excursions/island- hopping/galapagos-multisport-tour-8-days-7-nights/attachment/galapagos-sea-lion-and-pup/
Koghul, A. (2014). Blue footed booby a piece of study. Retrieved from http://ourworldstuff.com/animals-and-pets/blue-footed-booby-a-piece-of-study/
Invasive Animals CRC. (2013). Judas technique for feral goat control. Retrieved from http://www.pestsmart.org.au/judas-technique-for-feral-goat-control/
Wikipedia. (2009). Galapagos Land Iguana. Retrieved from https://commons.wikimedia.org/wiki/File:Gal%C3%A1pagos_land_iguana_(4201794181).jpg
WWF. (2015). Marine Iguana. Retrieved from http://www.worldwildlife.org/species/marine-iguana
Brinkhuizen, D. (2014). Medium Tree-Finch. Retrieved from http://ibc.lynxeds.com/photo/medium-tree-finch-camarhynchus-pauper/female-presumably- species
Cross, J. (2011). Various Critters of the Galapagos. Retrieved from http://www.pbase.com/johncrossphotography/image/139342831
Ecotourism. (n.d.). Galapagos Island Cruises. Retrieved from http://www.ecotourism.ca/galapagosislandcruise.html
Galapagos Cruises. (n.d.). Galapagos Islands. Retrieved from http://www.cruisesingalapagos.com/galapagosislands/
Gray, R. (2012). Lonesome George could be resurrected after cells are frozen by scientists. Retrieved from http://www.telegraph.co.uk/news/earth/wildlife/9468918/Lonesome-George-could-be-resurrected-after-cells-are-frozen-by-scientists.html
Ishpingo Tours. (2015). Galapagos Sea Lion and Pup. Retrieved from http://ishpingotours.com/tours-and-excursions/galapagos-tours-and-excursions/island- hopping/galapagos-multisport-tour-8-days-7-nights/attachment/galapagos-sea-lion-and-pup/
Koghul, A. (2014). Blue footed booby a piece of study. Retrieved from http://ourworldstuff.com/animals-and-pets/blue-footed-booby-a-piece-of-study/
Invasive Animals CRC. (2013). Judas technique for feral goat control. Retrieved from http://www.pestsmart.org.au/judas-technique-for-feral-goat-control/
Wikipedia. (2009). Galapagos Land Iguana. Retrieved from https://commons.wikimedia.org/wiki/File:Gal%C3%A1pagos_land_iguana_(4201794181).jpg
WWF. (2015). Marine Iguana. Retrieved from http://www.worldwildlife.org/species/marine-iguana