Guayaquil Pre Trip Readings
Geology of the Galapagos
Like many island chains around the world, the life of the Galapagos has been tumultuous. The Galapagos Islands lie on the Nazca plate, which is slowly moving east and colliding with the South American plate. This collision also gave rise to the Andes Mountains, and this subduction zone which is part of the pacific ring of fire is responsible for some of the world’s most violent earth quakes. As the plate moves, it does so over a hotspot, or plume of magma close to the surface of the earth’s crust. This hotspot is responsible for the volcanic activity that over time has given birth to this island chain. Volcanic vents erupt at the ocean floor and as the lava cools, eventually a seamount forms. These are basically underwater mountains. Once the seamount breaks the surface of the ocean, it becomes an island. The newer islands of the Galapagos are the ones that are closest to the south east. Once a particular island moves away from the hot spot, the volcanoes formed become dormant, as they are cut off from the source of magma. Eventually the wind and waves will erode these islands back into the sea from which they were born, but this will take millions of years, and as long as the hotspot remains active new islands will continue to form. Source: http://www.geo.cornell.edu/geology/GalapagosWWW/GalapagosGeology.html
Like many island chains around the world, the life of the Galapagos has been tumultuous. The Galapagos Islands lie on the Nazca plate, which is slowly moving east and colliding with the South American plate. This collision also gave rise to the Andes Mountains, and this subduction zone which is part of the pacific ring of fire is responsible for some of the world’s most violent earth quakes. As the plate moves, it does so over a hotspot, or plume of magma close to the surface of the earth’s crust. This hotspot is responsible for the volcanic activity that over time has given birth to this island chain. Volcanic vents erupt at the ocean floor and as the lava cools, eventually a seamount forms. These are basically underwater mountains. Once the seamount breaks the surface of the ocean, it becomes an island. The newer islands of the Galapagos are the ones that are closest to the south east. Once a particular island moves away from the hot spot, the volcanoes formed become dormant, as they are cut off from the source of magma. Eventually the wind and waves will erode these islands back into the sea from which they were born, but this will take millions of years, and as long as the hotspot remains active new islands will continue to form. Source: http://www.geo.cornell.edu/geology/GalapagosWWW/GalapagosGeology.html
Galapagos Colonists
Since the Galapagos are located about 600 miles off of the coast of Ecuador, it has always been interesting to think of how the diversity of life had arrived there. Sea birds would have no problem reaching these islands and were probably some of the first visitors. They could have also brought over some of the first plants from seeds that hitched a ride on their feathers or in their gut. There are very few flowering plants that call the Galapagos their home, and this is probably because there are not enough pollinators for them to have survived. Many of the plants that thrive on the islands are very hardy and their seeds are dispersed by the wind, like with dandelions. Other early colonists may have drifted over from the mainland on rafts of floating vegetation. There are no native amphibians on the Galapagos and this could be due to the fact that they would have not been able to survive the salty conditions on these rafts. Reptiles were more likely hardier sea farers, and this explains why they are diverse on the islands.
What really blows my mind is the voyage that some of the insects would have taken. They could have been blown in with the winds. Imagine being a tiny insect or spider, being blown high into the air and happening to land somewhere that you can live. The conditions must have been extremely challenging for any of the first colonists and it is amazing that they survived and even thrived on these islands. Today, new species are still arriving on the Galapagos, but unfortunately, these are being brought over by humans, and they are wreaking havoc on the delicate ecosystems that have been undisturbed for centuries. Domesticated animals such as goats and cats eat all of the vegetation, and kill native birds, respectively. Rats and other animals have been introduced as well. It is clear that in order to be one of the first colonists of a volcanic island; you have to be one hardy organism, one that can survive a voyage 600 miles over open ocean. Then if you manage to survive the voyage, you must be able to adapt and eventually thrive in this new habitat. This is exactly what all of the Galapagos natives have managed to do so far, only now threatened by humans and their activities. Let us hope that they can continue to adapt in spite of this.
Source: http://www.galapagos.org/about_galapagos/species-arrival-and-evolution/
Since the Galapagos are located about 600 miles off of the coast of Ecuador, it has always been interesting to think of how the diversity of life had arrived there. Sea birds would have no problem reaching these islands and were probably some of the first visitors. They could have also brought over some of the first plants from seeds that hitched a ride on their feathers or in their gut. There are very few flowering plants that call the Galapagos their home, and this is probably because there are not enough pollinators for them to have survived. Many of the plants that thrive on the islands are very hardy and their seeds are dispersed by the wind, like with dandelions. Other early colonists may have drifted over from the mainland on rafts of floating vegetation. There are no native amphibians on the Galapagos and this could be due to the fact that they would have not been able to survive the salty conditions on these rafts. Reptiles were more likely hardier sea farers, and this explains why they are diverse on the islands.
What really blows my mind is the voyage that some of the insects would have taken. They could have been blown in with the winds. Imagine being a tiny insect or spider, being blown high into the air and happening to land somewhere that you can live. The conditions must have been extremely challenging for any of the first colonists and it is amazing that they survived and even thrived on these islands. Today, new species are still arriving on the Galapagos, but unfortunately, these are being brought over by humans, and they are wreaking havoc on the delicate ecosystems that have been undisturbed for centuries. Domesticated animals such as goats and cats eat all of the vegetation, and kill native birds, respectively. Rats and other animals have been introduced as well. It is clear that in order to be one of the first colonists of a volcanic island; you have to be one hardy organism, one that can survive a voyage 600 miles over open ocean. Then if you manage to survive the voyage, you must be able to adapt and eventually thrive in this new habitat. This is exactly what all of the Galapagos natives have managed to do so far, only now threatened by humans and their activities. Let us hope that they can continue to adapt in spite of this.
Source: http://www.galapagos.org/about_galapagos/species-arrival-and-evolution/
Introduced Species
Of the many introduced species in the Galapagos, some have been more troublesome than others. Goats and feral pigs have become quite a big problem. The method for controlling these animals has been one of eradication. Feral pigs are actually a big problem throughout the southern United States as well. Wherever they become established they consume vegetation and destroy habitats that are critical for the survival of other species. In the Galapagos, they have been eradicated by extensive hunting and poisoning. Donkeys and Goats have also been eradicated from the islands. Areal hunting was the most efficient method of controlling these populations. People flying around in helicopters would just shoot the animals from the sky. Eventually the goats figured out that death from above was imminent when they heard the sounds of helicopter rotors, so they would scramble for cover. This led to the creating of a “Judas goat” or a goat outfitted with a radio collar so that the hunters could track its whereabouts when it returned to the herd, thus revealing their position. This method was very effective, albeit it drew a lot of fire from animal rights groups.
Personally I think that these kinds of eradications are necessary for the continued survival of this diverse ecosystem. It comes down to the greater good. Do we risk losing this priceless ecosystem for a bunch of goats? Or do we get rid of the goats and preserve a treasure. This discussion would not even be taking place if the eradications where happening to other organisms. Take for example the Ebola or small pox viruses, no one defends their right to exist and consequently the latter has been eradicated from the whole world. This was done for the greater good. Preserving the Galapagos for future generations is a great task that outweighs the lives of these goats, donkeys and feral pigs. I see no problem with these methods as long as they are done as humanely as possible. These methods have been adopted for eradicating feral populations of livestock animals in other islands around the world as well. Now if only we could keep ourselves from reintroducing them or bringing in something that is more difficult to eradicate!
Source: http://amalavidaexperience.weebly.com/uploads/3/9/0/2/39029957/paper-feralpigeradicationsantiago2004.pdf
https://www.wnyc.org/radio/#/ondemand/388850
Of the many introduced species in the Galapagos, some have been more troublesome than others. Goats and feral pigs have become quite a big problem. The method for controlling these animals has been one of eradication. Feral pigs are actually a big problem throughout the southern United States as well. Wherever they become established they consume vegetation and destroy habitats that are critical for the survival of other species. In the Galapagos, they have been eradicated by extensive hunting and poisoning. Donkeys and Goats have also been eradicated from the islands. Areal hunting was the most efficient method of controlling these populations. People flying around in helicopters would just shoot the animals from the sky. Eventually the goats figured out that death from above was imminent when they heard the sounds of helicopter rotors, so they would scramble for cover. This led to the creating of a “Judas goat” or a goat outfitted with a radio collar so that the hunters could track its whereabouts when it returned to the herd, thus revealing their position. This method was very effective, albeit it drew a lot of fire from animal rights groups.
Personally I think that these kinds of eradications are necessary for the continued survival of this diverse ecosystem. It comes down to the greater good. Do we risk losing this priceless ecosystem for a bunch of goats? Or do we get rid of the goats and preserve a treasure. This discussion would not even be taking place if the eradications where happening to other organisms. Take for example the Ebola or small pox viruses, no one defends their right to exist and consequently the latter has been eradicated from the whole world. This was done for the greater good. Preserving the Galapagos for future generations is a great task that outweighs the lives of these goats, donkeys and feral pigs. I see no problem with these methods as long as they are done as humanely as possible. These methods have been adopted for eradicating feral populations of livestock animals in other islands around the world as well. Now if only we could keep ourselves from reintroducing them or bringing in something that is more difficult to eradicate!
Source: http://amalavidaexperience.weebly.com/uploads/3/9/0/2/39029957/paper-feralpigeradicationsantiago2004.pdf
https://www.wnyc.org/radio/#/ondemand/388850
Biodiversity
I would be remiss to talk about the Galapagos Islands and species diversity and not mention the Galapagos Tortoises. They are the islands namesake after all. These incredible creatures can live well past a century and reach 5 feet in length and weigh up to 550 pounds. They are the largest tortoises in the entire world and are among the oldest living vertebrates on the planet. There are 11 distinct species of tortoise on the islands and this is down from the 15 that where present when Darwin arrived. Some became extinct due to natural causes, such as active volcanism, but most have been done in by habitat loss and exploitation. Their ability to go without food and water for an entire year made them a transportable source of fresh meat for any seafarers traveling by the Galapagos. Turtle oil was used to light lamps in Quito. Lonesome George was believed to be the last remaining tortoise of his species and he passed away in 2012. All the Galapagos tortoise species are protected by the federal government of Ecuador and efforts to preserve them have been put into place such as captive breeding and habitat restoration.
Another amazing animal that calls the Galapagos home is the marine iguana. It is the only lizard that frequents the ocean to forage for food. This type of behavior is perfectly suited for a habitat that requires adaptation. The lizard’s dark skin makes it able to absorb a lot of sunrays so that it can quickly get back into the cold water. These lizards actually have been known to shrink in times of food scarcity. They literally dissolve their own bones as a source of nutrients. It will be interesting to see how the iguanas are doing this year, as a strong El Niño is present, and during these strong El Niño events, marine iguana mortality is high because of lack of food. There are also land species of iguanas as well. They have a unique relationship with Darwin’s finches, often letting the small birds pick out ticks from in between their scaly folds. A big threat to these iguanas is feral cats and dogs which kill juveniles and adults alike. In order to protect them, these feral populations of house pets are eradicated, especially if they are present in iguana breeding habitat.
It is clear to me that in order to protect the variety of life and biodiversity of the Galapagos Islands, human introduced species must be removed, and habitat preservation must be a priority. These two issues alone seem to be the ones that cause the most damage to these unique animals and the ecosystems which they are part of.
Source: http://www.galapagos.org/about_galapagos/tortoises/
http://www.galapagos.org/about_galapagos/reptiles/
I would be remiss to talk about the Galapagos Islands and species diversity and not mention the Galapagos Tortoises. They are the islands namesake after all. These incredible creatures can live well past a century and reach 5 feet in length and weigh up to 550 pounds. They are the largest tortoises in the entire world and are among the oldest living vertebrates on the planet. There are 11 distinct species of tortoise on the islands and this is down from the 15 that where present when Darwin arrived. Some became extinct due to natural causes, such as active volcanism, but most have been done in by habitat loss and exploitation. Their ability to go without food and water for an entire year made them a transportable source of fresh meat for any seafarers traveling by the Galapagos. Turtle oil was used to light lamps in Quito. Lonesome George was believed to be the last remaining tortoise of his species and he passed away in 2012. All the Galapagos tortoise species are protected by the federal government of Ecuador and efforts to preserve them have been put into place such as captive breeding and habitat restoration.
Another amazing animal that calls the Galapagos home is the marine iguana. It is the only lizard that frequents the ocean to forage for food. This type of behavior is perfectly suited for a habitat that requires adaptation. The lizard’s dark skin makes it able to absorb a lot of sunrays so that it can quickly get back into the cold water. These lizards actually have been known to shrink in times of food scarcity. They literally dissolve their own bones as a source of nutrients. It will be interesting to see how the iguanas are doing this year, as a strong El Niño is present, and during these strong El Niño events, marine iguana mortality is high because of lack of food. There are also land species of iguanas as well. They have a unique relationship with Darwin’s finches, often letting the small birds pick out ticks from in between their scaly folds. A big threat to these iguanas is feral cats and dogs which kill juveniles and adults alike. In order to protect them, these feral populations of house pets are eradicated, especially if they are present in iguana breeding habitat.
It is clear to me that in order to protect the variety of life and biodiversity of the Galapagos Islands, human introduced species must be removed, and habitat preservation must be a priority. These two issues alone seem to be the ones that cause the most damage to these unique animals and the ecosystems which they are part of.
Source: http://www.galapagos.org/about_galapagos/tortoises/
http://www.galapagos.org/about_galapagos/reptiles/