By Austin Thomasmeyer Introduction to the Galapagos Penguin The Galapagos Penguin (Spheniscus mendiculus) is one of the world’s seventeen species of penguins. This type of penguin can only be found in the Galapagos Islands, hence the name Galapagos penguin. This is the only species of penguin to be found anywhere in the world besides the Antarctica continent, and the only penguin species located in the Galapagos Islands near the equator. The penguin’s unique features alongside the unordinary nature and biology of the climate that it lives in makes the Galapagos Penguin a unique subject of research. It is one anomaly of science that we are still working towards learning more about and how to conserve their existence in our oceans and islands. Where They Live The majority of the population of the Galapagos penguins reside on the western islands and shores of the Galapagos Islands. This where most of the penguin’s nest, breed, and forage. The penguins choose this location due to the fact that this part of the islands is affected by the cold oceanic upwelling along the equator and the Equatorial Under Current, or more commonly known as the Cromwell current. This upwelling effect causes the penguins climate that it leaves in to have cooler than normal water temperatures, which allows the penguins to be in a familiar cold-water climate just as the other species of the penguins live. Galapagos Penguins primarily build nests that are relatively close to the water’s edge, usually right around the sea level. This nesting location is primarily where the penguins forage for food along the coast and in shallow waters. The disbursement of the penguins is linked with the nutrient rich waters along the western coasts of the Galapagos islands which provide a strong supply of prey when the coastal upwelling is present. What They Eat The diet of the Galapagos Penguin is an area of the research in the species that is ongoing and not too detailed at this point in time. For now, we have observed that these animals are fairly opportunistic feeders that tend to forage within a kilometer of the shore on land and close to the shore at sea. The penguins can be seen preying on species such as sardines, piquitingas, and mullets and this list of prey is primarily responsible for what we know as the penguins’ main makeup of its diet. The availability of prey can be dependent on the weather and the upwelling conditions off the coast of the western islands. If the weather is too warm and the upwelling effects of the area are minimal, that could cause less schooling of sardines and mullets in the area. This will lead to a decrease in availability of the penguins’ crucial food sources that keep them alive and healthy especially during breeding seasons. What Eats Them The Galapagos Penguins have relatively few natural predators in the islands, but are still apart of the food chain. The biggest animal type threats to the penguins are introduced predatory species such as rats, dogs, and cats. The deadliest to fledgling and adult penguins is the feral cat species. These cats prey on newly born penguins and eggs from the nest. This species of feral cats has been closely monitored as to help the population of penguins survive on the islands. Although the penguins are sought out as prey, the deadliest factors that come into the penguins’ lives are through bycatch and climate changes that affect the penguins living and hunting conditions. While the penguins’ main sources of food are sardines and mullets of the like it is easy for Galapagos penguins to be caught and killed as bycatch to fishermen looking to catch the schools of fish that the penguins may be feeding on. Climate change is another important factor in the risks that threaten the penguins’ way of life. If the weather and climate in which they live gets warmer it can decrease amount of nutrients in the waters surrounding the nests of the penguins that will consequently reduce the amount of prey in the penguins’ food web. Endangerment Status The Galapagos Penguin species is one of the five species of penguins that are on the endangered species list. Penguins in general breed at an older age and are slow and clumsy while walking on land which are factors that lead to the lower population numbers among penguins. Surface water temperatures that are warmer than usual can cause threats to the penguins in the way of prey source declines and higher water levels. The nests of the penguins are so close to the water’s edge that it has been seen that a rogue passing wave can sweep a whole nest into the water and drown new hatchlings and submerge eggs. Feral dogs and cats that have been introduced to the area of the penguins carry threats towards the species. The feral dogs can carry and transfer diseases to the penguin population that can kill large sums of the species leading to declining numbers over the years. Feral cats that have been on the island has been introduced and have been one of the largest predators of species. According to the World Wildlife Foundation the current population numbers of the Galapagos penguins in the world are less than 2000 individual penguins, which lands them on the list of endangered species of the world. The breakdown of recent population numbers through the years can be seen in Tables 1 & 2. The entirety of the remaining penguins resides in the Galapagos National Park which allows conservative actions to take place freely. Access to breeding grounds has been strictly monitored to specific licensed researchers as well as restrictions on studies done on the penguins in general are just a few conservative actions that have taken place in order to save the population form extinction. The numbers of predators on the islands such as feral cats, dogs, and rats are closely monitored and have been eradicated in some parts of where the penguins live. The commercial fishing industry near the waters of the Galapagos islands has been severely reduced and monitored in order to protect the remaining population from getting drowned in float nets cast by fishermen in hopes of catching other types of fish. Conclusion The Galapagos Penguins are a unique species of penguins that reside solely in the Galapagos Islands. They are on the endangered species list due to climate change and severe predation from introduced species that spread diseases and prey on newly hatch penguins as well as eggs in the nest. This species of penguin is a known shallow water diver that swims no more than 50 meters below the water’s surface in search of food as well as foraging the surrounding coastal areas. References Boersma, P. D., Cappello, C. D., & Merlen, G. (2017). First observations of post-fledging care in galapagos penguins (spheniscus mendiculus). The Wilson Journal of Ornithology, 129(1), 186-191. “Galápagos Penguin.” WWF, World Wildlife Fund, www.worldwildlife.org/species/galapagos-penguin. “Galapagos Penguin Spheniscus Mendiculus.” Datazone.birdlife.org, datazone.birdlife.org/species/factsheet/galapagos-penguin-spheniscus-mendiculus/text. Karnauskas, K. B., S. Jenouvrier, C. W. Brown, and R. Murtugudde (2015), Strong sea surface cooling in the eastern equatorial Pacific and implications for Galápagos Penguin conservation, Geophys. Res. Lett., 42, 6432–6437 “Penguins Endangered.” Penguins-World.com, Penguins-World , www.penguins-world.com/penguins-endangered/. Vargas, F. Hernan, et al. “ Biological Conservation Biological Effects of El Niño on the Galápagos Penguin.” Biological Conservation, vol. 127, no. 1, Jan. 2006, pp. 107–114.ScienceDirect.
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Biology of the Sea
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