Wildlife of the Galapagos Islands The Galapagos Islands have been known to be one of the most unique locations for the study of biodiversity and environmental issues. The high amounts of biodiversity have been made possible by the geological makeup of the islands. As I have stated in my review of Guayaquil, the location of the islands along the equator, creates both sunny and hot conditions and cool ocean currents. This combination causes tropical and temperate conditions, providing the best environment for the unique and complex diversity found on the islands. The islands are home to a large variety of different species of animals such as giant tortoises, flightless cormorants, hammerhead sharks, and Galapagos penguins. The islands are also inhabited by a variety of different species of plant vegetation such as mangrove forests, succulent cacti, and Scalesia trees. Many of the wildlife and vegetation species inhabiting the islands are known to be endemic of the islands, meaning they can only be found in one geographic region. The Galapagos penguin, Galapagos giant tortoise and Wave Albatross, for example, are all species of wildlife that are endemic to the islands. The vegetation and wildlife of the Galapagos have a very strong relationship with each other. Vegetation especially provides life for the islands. Without the unique and diverse amounts of vegetation, life would not be possible. The wildlife on the islands depend on the vegetation for their dietary needs, nesting grounds and shelter.
Conserving the Last Eden As stated previously, the Galapagos Islands are home to several endemic species of wildlife and plant vegetation. In order to protect the unique ecosystem, the islands were officially declared as a national park in 1959 and a world natural heritage site in 1979. To further conserve and protect the diversity of the Galapagos Islands, the Special Law of the Galapagos was created in 1998. Although these declarations and laws were made to protect the islands, the Galapagos Islands have since been added to the UNESCO’s list of World Heritage Sites in danger. This endangerment has caused a need for regulation of visitors in and out of the islands and the decrease of residents inhabiting the islands. The islands are threatened by invasive species, human population growth, tourism, and pollution.
The foot traffic of tourist and the vessel roots of ships have brought over several invasive species such as goats, pigs, donkeys and rats. Many of these introduced species have caused endemic species loss from overgrazing, egg and hatch-ling predation, and introduction of disease. Solid waste and oil spill pollution has further declined the endemic species populations. The Jessica Oil Spill in 2001, for example, affected marine iguanas and caused a significant decrease in their population. Global pollution has also caused a decrease in species. In 1440, the use of pesticides, specifically DDT, was used by the U.S. military base located on the islands. DDT, although used to protect human health, has a very slow rate of degradation and has since negatively affected the lives of wildlife on the islands. Animal captured and biopsies of sea lion pups have been conducted to determine the harmful effects of DDT. It was determined the pesticide has affected their biological processes. In order to continue the protection of the Galapagos Islands, education of present and future generations must be implicated to preserve the natural beauty and diversity of the islands. Reference: Klassen, C. 2017. The Galapagos National Park. Santa Cruz II.
Submarine Morphology Determining and understanding the morphology and structure makeup of the oceanic islands in hot spots helps to further understand how the Galapagos Islands developed and evolved. To do this, multi-beam bathymetric and MR1 side scales sonar technologies were used. The youngest of the islands can be found towards the western edge of the archipelago because of eastward movements of the tectonic plates, also known as the Nazca Plate. As discussed previously in the Guayaquil readings, the lithosphere of earths layers contains on average two dozen plates that move with one another in the asthenosphere layer. As the plates move, the Earth experiences convection which causes heat loss. When the plates move across a mantle plume, chains of volcanoes are produced. The top three geo-morphologic components of the western Galapagos Archipelago were determined to be volcanic cones, deep lava fields and rift zones.
Invasive Species One of the main causes of species endangerment and extinction is the introduction of non-native mammals. Feral goats, donkeys, and pigs, for example, has caused both direct and indirect affects to the island’s ecosystem. They have contributed to ecosystem degradation and biodiversity loss due to overgrazing, predation and food loss. Feral donkeys have trampled tortoise and iguana nests, decreasing their populations. Feral pigs have preyed on animal eggs and hatch-lings. Feral goats have been the main suspects for ecosystem degradation and biodiversity loss.
In order to conserve the ecosystem biodiversity, the eradication of invasive species was used as a powerful tool. Eradication techniques include aerial hunting, dog hunting, poisons, monitoring programs and educational campaigns. Unfortunately, the most successful techniques of eradication have not been recorded, making it difficult to determine the most effective techniques for removal. After 120 years, feral goats, donkeys and pigs have been successfully removed from Santiago Islands, Alcedo Volcano and five other islands.
Population Growth and Tourism The islands are one of the worlds most popular and premier ecotourism destinations due to the wide variety of wildlife and beautiful ecosystem. Tourism has brought in hundreds of millions of dollars to Ecuador national economy which has generated revenue and population growth. The history of tourism in the Galapagos Islands began in the 1960s. During this time, a half dozen of both hotels and shipping vessels held an average of 2,000 tourists each year. The rapid population growth in Ecuador began during 1970s. Since 2006, there has been an increase of about 80 shipping vessels and 65 hotels, holding an average of 3,500 tourists each night. Like all things in life, tourism has both advantages and disadvantages.
Advantages:
Tourism fees support conservation and protection of the islands
Increases net revues
Economy and living conditions improved in certain areas
Disadvantages:
Invasive species introduction and destruction
Conservation goals conflicts
Wildlife disturbance and decline
Marked decline in the beauty of the islands by surveyed visitors
Increased economy to support tourism
Sustainable Ecotourism As previously stated there are both advantages and disadvantages. Tourism has caused minor trail wear and erosion. It is believed that tourists may also disturb nesting birds, increasing their heart rate and increasing their body temperatures. It is also reported that tour ships and tourists have left behind trash and plastics in the waters. Trash pollution has caused the deaths of sea lions and sea birds, being killed by trash strangulation. Tourism has further led to increased development, biodiversity and species loss. The airport and road ways of the islands have been expanded to support the increase of human population and tourism. This expansion has led to fragmentation and habitat destruction. Apart from the environmental impacts, towns like Puerto Ayora have experienced impacts to their city services and increased crime rates. Demand for ecotourism has changed the methods of travel agencies. Tourists are no longer interested in relaxing by the pools and beaches, they are more interested in making memories and learning more about the location they are visiting. For example, tours of the Galapagos has educations tourists about the history of the Charles Darwin Foundation and educating the public about the importance of conserving the islands. Due to this, ecotourism has become a very influential method for the sustainability of environmental conservation and protection. The goals of preservation of the environment and sustainable ecotourism has been internationally accepted and has brought countries together to work towards a common goal. Debt for nature swaps, for example, have been internationally accepted and implemented to protect the environment while decreasing a countries debt. Nature tourists will spend around $1,000 in two weeks, increasing the countries revenue. Sustainable tourism has been implemented for twenty years with some success. This success has been made possible by balancing both conservation and development. This balance includes natural resource management, sustained observation and monitoring.
Charles Darwin’s Origin of Species The theory of Charles Darwin was created by the idea of variation. The species discussed by Darwin were differentiated by numerous trains and adaptations, of which are responsible for the species evolution. These differential characteristics can be seen through the color, body structure, and physical traits of a species. Hereditary has allowed for these variations of traits to be passed down to the species offspring. Although physical traits are important for evolution, the most important trait is the ability to adapt and survive in their natural habitat. The beaks of birds, for example, have evolved over time and has made collecting insects easier. Darwin hypothesized that the physical traits, although minor, are related to distinct variations found within other species. This hypothesis of variation and evolution explains how the origin of species was created and further explains the process of natural selection, the main component of Darwin’s theory. Similar to the idea of exponential growth, Darwin explained that the possibility of continuous population growth is impacted and halted by the geology and natural resources of the inhabited area (i.e limitations of available food and water). This stoppage being the creation of natural selection and the reason for a species survival. Furthermore, the greater the variation and adaptations of a species, the greater the chances are of a species surviving natural selection. The longer a species survives natural selection, the greater the chances will be that their offspring inherits these survival traits. As the future generations of species inherit those traits, the species will begin to diverge from its original origin and become a species of their own. This process being explained as Charles Darwin’s theory of evolution.
Origins of Birds Before birds evolved into the feather covered creatures they are today, they first had scaly skin, sharp teeth and claws. It is believed that reptiles are the ancestors of birds. Scientists discovered a 150 year old fossil named Archaeopteryx. It was determined that the fossil had feathered three digit wings, a boney tail, teeth, and claws. Several years later scientists further discovered another fossil, that resembled Archaeopteryx, named Compsognathus. This reptilian creature had three digits in its hands, hollow bones and stood on two legs. These discoveries led some scientists, like Thomas Hucksley and John Ostrom, to believe that birds descended from reptiles, specifically dinosaurs to be exact. Although these fossils shared similarities with birds, many people were skeptical of this relation. It was believed that dinosaurs were large, cold blooded and slow moving animals which resembled nothing like a bird. Many previously discovered dinosaur fossils also did not contain a wish bone, as birds do. This skepticism was eventually challenged and laid to rest in 1963. John Ostrom discovered a dinosaur fossil in Montana, named Deinonychus. The fossil was very small, ran upright on two legs, and had a tail used for balance. This fossil proved to scientists that dinosaurs in fact could be warm blooded and agile. When comparing Deinonychus and Archaeopteryx, it was determined they were very similar and birds did in fact evolve from dinosaurs, specifically Theropods. To further support this evidence, a wish bone was discovered in a dinosaur fossil named a Tyrannosaurus. The evidence found that finally supported the theory of bird and dinosaur ancestry took place in the mid-1990s. A 120 million year old dinosaur fossil named Caudipteryx was discovered. This fossil was the size of a chicken, and had feathered hands and tail. Although these dinosaurs were flightless, feathered creatures it was believed that dinosaurs depended on the feathers for insulation and communication, as do some birds. It was believed that all dinosaurs became extinct 66 million years ago after a asteroid hit earth but one theropod species survived. This species survival led to the evolution of Avian dinosaurs, the birds that exist and live among us today.
Evolution of the Galápagos and Finches During Charles Darwin exploration of the islands he noticed significant differences between the animals and plants on each island, many of which were aboriginal creatures to the islands. Darwin explored four islands, all of which had its own species of animals and plants inhabiting it. Every animal and plant appearing different than the last island explored. The beaks of birds, for example, were either larger or smaller than another species. Darwin hypothesized that the size of the beak developed to fit the appetite of the bird. The warbler finch has a fine, small beak used to pick off insects. The woodpecker finch has a very robust beak used to peck through trees for beetle and termite larvae. The cactus finch has a very long, sharp beak used to break through cacti.
The coloration and body size of bird species were also different among others of the same species. It was discovered, through DNA sampling, that each species of finches (13 species) are closely related to each other and share a single common ancestor. Over time, a new species of finch being evolved into its own species. This process taking place when two species of birds becoming geographically separated. Once the species begin to develop different features, they no longer mated with one another and only mated with the species with similar characteristics. Apart from the differences in appearance, it was determined that each species of finch developed their own specific song. It appears that male finches are only attracted to females that sing the same song and share the same appearances as themselves. This keeping different species of finches from mating with one another. One of the islands to be explored the most by scientists is the Daphne Major Island, the laboratory of evolution. Here is where the discovery of evolutionary differential features of birds took place. Daphne Major Island is inhabited by a large population of several different species of finches. After several studies and experiments, it was determined that changes in the environmental conditions affected the finches and caused their need to evolve. In 1977, the islands experienced a drought and a loss of vegetation.
When there were drier seasons, larger seeds were plentiful while smaller seeds were not. It negatively affected smaller beaked birds and it was very beneficial for larger beaked birds. Larger seed availability guaranteed the survival of larger beaked birds and allowed for their offspring to inherit larger beaks. In 1983, El Niño brought heavy rains to the islands. Their studies found that when there was a heavy rain fall, smaller seeds were plentiful while larger seeds were not. Although this negatively affected larger beaked finches, it was very beneficial for finches with smaller beaks. Smaller seed availability guaranteed the survival of smaller beaked birds and allowed for their offspring to inherit small beaks. Scientists discovered that these evolutionary changes occur monthly and/or annually. The more diverse the environment, the more chances of evolutionary changes. The evolution of finches illuminated how the diversity of life arose and continues to evolve. Furthermore, Darwin’s theory of evolution was proved to be more than just a theory.