Penguins Essay Research Paper The signature Species
Penguins Essay, Research Paper
The signature Species of the Southern Hemisphere (Antarctica) – the mascot if you will – is the penguin. There are not one and no fewer than seventeen species of penguins. Penguins are flightless birds in which several factors are contributing to the reduction of the penguin population. These contributing factors are both man-made and naturally occurring.
?The origin of the word ?penguin? has been the subject of debate for a long period of time. Researchers and historians? theories range from reference to the amount of fat (penguigo in Spanish and pinguis in Latin) penguins possess to the claim that the word was derived from two Welsh words meaning ?white head?.? (Sparks and Soper, 1987) Penguins are comical and funny birds. Blue/black on the upper half of their body and white on the lower half, they look as though they are all dressed up for a formal dinner or show but have no place to go! Penguins are flightless birds, which have adapted to living in the cooler waters of the Southern Hemisphere. They generally live on islands and remote continental regions that are free of land predators. Their inability to fly has been detrimental to their survival on land. Some species of penguins spend as much as 75% of their lives in the ocean, yet they all breed on land or sea ice attached to land. The seventeen species found today are thought to have evolved from flying birds more than forty million years ago. To date, the discovery of all penguin fossil fragments has been limited to the Southern Hemisphere. ?Records show that prehistoric penguins were found within the range of present-day penguins.? (Sparks and Soper, 1987)
All penguins have a very similar torpedo-shaped body form, which is conducive for swimming. They have a large head and a short neck with an elongated body. Penguin species vary greatly in size. For example, the Emperor penguin is the largest of the penguin species, standing 3.7 feet and weighing between sixty and ninety pounds. The smallest penguin in the species is the Fairy penguin, standing only sixteen inches and weighs less than 3 pounds. Penguin?s wings are highly modified to form a stiff paddle-like flipper used for swimming. ?Each flipper is covered with short, scale like feathers. The long wing feathers typical of most birds would be too flexible for swimming through water.? (Sparks and Soper, 1987) A penguin?s tail is short and wedged shaped with fourteen to eighteen stiff tail feathers. The legs and webbed feet with visible claws on a penguin are set back on the body so that when on land, the penguin is able to stand. ?Penguins walk with short steps or hops, sometimes using their bills or tails to assist themselves on steep climbs.? (del Hoyo, et al., 1992) When in the ocean swimming, penguins use their feet and short stubby tail as a rudder to guide them through the water. Penguin?s bones are solid and heavy which help them to remain submerged to reduce the energy that they need for diving.
Penguins are able to withstand the extreme cold because of the insulation provided by their feathers. Feathers are highly specialized, broad and closely spaced helping to keep water away from the penguin?s body. Penguins have more feathers than most birds, having about seventy feathers per square inch on their body. Most penguin species goes through one complete molting cycle per year, which usually happens after breeding season. ?The exception to this is the Galapagos penguin which annually go through 2 molts.? (del Hoyo, et al., 1992) For penguins, molting is a very important process because feathers wear out when penguins come in contact with each other, as well as with the ground and water. The molting period varies between one species to another. Usually the time period is anywhere from thirteen to thirty-four days.
Regular preening of the feathers is essential as penguins obtain oil from their tails to coat their feathers for waterproofing. Penguins in warmer temperate zones have a thinner plumage of feathers and fat layer than their counterparts of the polar species. To keep warm in near freezing waters, penguins have a highly developed heat exchanged system of blood vessels in the flippers and legs which helps the heat loss at the core of the body. To avoid heat loss in a penguin?s body, the penguin has 2 internal temperatures. A penguin has a normal body temperature and a temperature of the environment close to the limbs of the body. Tropical penguins can overheat very easily; so in order for them to lose the body heat, they usually use their flippers to get rid of excess heat. They also have bigger flippers than their polar penguin ancestors.
Penguins communicate with each other by different ritual behaviors such as head and flipper waving, calling, bowing, gesturing and preening. Penguins communicate by ?displays? or vocalization and performing physical behavior. ?They use many vocal and visual displays to communicate nesting and territories along with mating information. They also use displays in partner and chick recognition, and defense of intruders.? (Sparks and Soper, 1987) Territorial disputes can lead to aggressive postures such as stares, pointing and even charging each other. Also during courtship and mating, other rituals are included which are called ecstatic displays. In these particular displays, an unattached male penguin will pump his chest several times, stretch his head upwards and move his flippers about away from his body. During this display, the male penguin also emits a loud harsh sound. In doing this, other male penguins in the colony begin to exhibit the same behavior which in turn begins the breeding cycle within the colony. When breeding occurs, one is unable to distinguish male and female penguins because they are not sexually dimorphic. There is one particular penguin that one can be told apart called the Crested penguin. Other ways of telling which penguin is male or female is that males are usually more robust and have larger bills. Also during mating season, female penguins are identifiable by muddy footprints left behind by males during mating activity.
Males and female penguins may take from 3 to 8 years before they reach sexual maturity. With some smaller species of penguins, breeding can occur between 3 and 4 years; but with larger penguins, breeding does not occur until much later in life, and then some do not breed until the eighth year. The King penguin has the longest breeding cycle of all of the penguin species, lasting fourteen to sixteen months. ?A female King penguin may produce a chick twice in every 3 breeding seasons.? (Sparks and Soper, 1987) The Fairy penguin has the shortest breeding cycle in the species, about fifty days. When penguins begin to mate, the courtship varies from species to species. Courtships begin with both visual and auditory displays as mentioned above. In many of the species, the male displays first to establish a nesting site and then attracts a suitable mate. However during this display, the female makes the mate selection. Most penguin species are monogamous meaning one female breeds with one male during a breeding season. However, if a male penguin arrives late to his destination for breeding, this could be grounds? for divorce. Most female Emperors and King penguins mate within twenty-four hours after arriving at the rookery. If the male is late or does not show up during this time period, the female will move on and find another mate.
When penguins return to the rookery each breeding season, most tend to be faithful and return to the same place. The males tend to arrive first to set up the nesting site prior to the females? arrival. ?Most species of penguins nest on the surface, in open habitats, and many have only a rudimentary nest consisting of a hollow amongst boulders, tussocks, or other vegetation lined with a few stones or pieces of grass.? (Williams, 1995) The Emperor and King penguins do not build a nest for their young. The reason for this is that when one of these species lays an egg, they stand upright while incubating a single egg. The eggs rest on the top their feet under a loose fold of skin. This loose fold of skin, which is used for incubating the egg, is called a broodpatch. The broodpatch contains numerous blood vessels that when blood is transferred to this area, heat is transferred to incubate the egg. After a female penguin lays her egg, she returns to the ocean to feed and the male incubates the egg on his feet for as long as sixty days or until the egg hatches and a baby chick emerges. Usually in most cases, the female Emperor penguin returns from feeding in the ocean just about the same time the egg is ready to hatch. If she does not return in time and the egg hatches, the male penguin feeds the baby chick with a milky fluid from his throat. The baby chick is covered with a downy coat and is kept under the broodpatch until it is 6 to 10 days old. After this period of time, the baby chick begins to regulate its own body temperature. Often chicks herd together in tight groups to keep warm from the freezing arctic air. The eggs of penguins tend to vary from species to species in regards to size, shape and weight. The colors of penguin eggs tend to be white, bluish or greenish. A chick depends on its parents for survival between hatching and obtaining its waterproof feathers. Once a chick has lost its down feathers and they have been replaced with waterproof feathers, the chick is able to enter the ocean and become somewhat independent of its parents.
Penguins are very efficient swimmers and; although they are used to swimming at speeds of 5 mph, some of the species can travel up to speeds of 8.9 mph, such as the Emperor penguin. When penguins are traveling through the water quickly, they will leap out of the water every few feet. This type of action is called ?porposing? due to the same behavior that resemble a porpoise. This action serves 2 purposes for a penguin; one being that a penguin needs to come up for air, and the other is to decrease their chances from being eaten by a predator.
When penguins are out at sea feeding, their diet is made up of krill, squid and fish. Smaller species of penguins feed on krill and squid whereas larger species tend to feed on squid and fish. Penguins rely on their eyesight when they are out hunting for food. ?It is not known how penguins locate their prey in the darkness, at night, or at great depths, but some scientists hypothesize that penguins are helped by the fact that many ocean squid, crustaceans, and fishes are bioluminescent (they produce light).? (del Hoyo, et al., 1992) When penguins are hunting for food, they catch their prey as they are swimming and swallow their food whole. Feeding areas vary for each species of penguins. When hunting for food they may be successful within a 9-mile radius, or they have been known to travel as far as five hundred and fifty nine miles to find food.
As penguins are swimming in the ocean waters, they have several predators including but not limited to; leopard seals, fur seals, sea lions, sharks or killer whales. On land, penguins have to worry about other predators such as foxes, snakes, and others that are not native to the lands but that have been transplanted by human migration. Examples of some of these non-native predators are; feral dogs, cats and stoats, which is a member of the weasel family.
Since penguins are the most aquatic of birds, El Nino has taken its toll on the existence of these fascinating creatures. This natural phenomenon, which changes wind and ocean current patterns, warms the surface temperatures and reduces the upwelling of nutrient-rich water. Marine animal food supply is directly affected and compromised by the above mentioned factors because of the decrease of nutrients within the water. Plankton, krill and small fish cannot thrive under these changes. ?To put it simply, the water?s too warm and there?s not enough food.? (Boresma). Water temperatures in the equatorial Pacific Ocean have been measured from eighty-three to eighty-four degrees Fahrenheit; which is much warmer than normal and, because of this, fish found in these waters cannot survive, they die or migrate. Penguins found in this region are undernourished and/or emaciated, with an absence of young or baby penguins.
Because of the shortage of food caused by El Nino, researchers have found that adults do not attempt to lay eggs. When eggs are laid however, many nests are left abandoned because the birds do not have enough food to remain in the area. ?When upwelling is absent, the birds forage singly or in pairs, they do not molt, and the few that initiate breeding rapidly lose weight and eventually fail.? (Williams, 1995) This contributes to the increasingly low penguin population and is directly caused by El Nino.
El Nino is a naturally occurring phenomena which cannot be controlled; however, the actions of humans and their subsequent effects on the population of penguins can be controlled. The biggest threat to marine species is the human impact. The killing of penguins dates back as early as the 1800s and was a major factor in the mortality rate of penguins. Penguins were hunted and killed so that the fat from their fat layers containing oil could be harvested and used for lighting, tanning of leather and fuel. This was an important source of obtaining these necessities in the 1800s and early 1900s.
Penguins were hunted and killed by early explorers for use as daily provisions; their carcasses were dried and salted for consumption. They were also a source of fresh daily meat. Fortunately for the penguins, their eggs were a more important food supply than themselves. Sailors on long voyages consumed large quantities of eggs in vast numbers as these eggs contained an immense amount of protein. ?Sometimes more than 300,000 eggs were taken at an annual harvest from one African Island.? (Sparks and Soper, 1987). The collection of penguin eggs is illegal and has been since 1969; however, believe it or not, it still continues to occur even today. The illegal killing of penguins also still occurs today as their meat is used for human consumption, as well as fishing bait in Chile and Peru.
In addition to penguins being hunted currently and in the past for use as a food source, they have great commercial value as nitrogen-rich fertilizer. The use of penguins as a fertilizer dates back as far as 500 B.C. The Incas used penguin and seabird guano to improve their crops. However, the Incas were careful to not over use their supply by limiting its use based on the rate that the penguins reproduced themselves. Today penguins are still a source for commercial nitrogen-rich fertilizer; however, today those harvesting it are not as thoughtful. Overexploitation for this use is seriously threatening some species and their population.
The dumping of garbage and trash in the ocean affects all kinds of marine life including the penguins. Penguins have been found tangled in debris, which causes death or serious injury. In addition to trash dumping, oil dumping also poses a great threat to the penguin population. When their feathers are tainted with oil, weatherproofing is reduced and their insulation fails. They are then at great risk of hypothermia. In addition, when trying to preen their feathers; they can ingest oil, which poisons them and causes their internal organs to fail.
Although oil spill disasters such as the Exxon Valdez spill off the coast of Alaska had a devastating affect on the population, oil also enters into the waters via ship sludge and residue. Facilities are available for ships too properly dispose of their sludge and residue; however, unfortunately these facilities may not be utilized as it may be cost prohibitive and therefore, illegal dumping is then opted. The dumping of oil waste is permitted; however, the rate must be 15 parts of oil to a million parts of water. This formula is not followed as the risk of being caught is so small compared to the cost of the mixing of the formula. Oil also enters into the marine habitat through land run-off. ?The U.S. Academy of Sciences estimated in 1990 that 37% of oil pollution of the world?s marine environment enters the sea from the land. Other sources estimate that 45% comes from shipping (12.5% from tanker accidents); 9% from the atmosphere, 7.7% from natural sources and 1.5% from offshore oil exploration and production.? (Environmental News Network).
In conclusion, the responsibility for the future existence of the penguin population lies mainly with the human race. Our ability to cause changes in climate snowballs thus creating changes in global and local patterns of ocean productivity. We have altered, and continue to alter, the natural environment and habitat of these wonderful creatures.
Historically, the direct exploitation of penguins by humans created a huge risk to their survival. Currently, as humans create more creative uses for penguins and their skins, we pose a greater risk of impacting their existence. The ability to control and monitor the use of these animals is complex and difficult. The need for protecting marine habitats for all kinds of marine life has become serious. We have the ability to cause the extinction of far too many creatures. As of December 4, 1998, a number of conservation groups gathered and formulated a report on the penguin population. They believe that 9 penguin species should have been endangered or were close to being endangered, and 2 more species close to being threatened. Previously, only 5 of the total seventeen penguin species were considered threatened. Based on the above-referenced conservation groups? statistics, more than 50% of penguin species may be close to endangered. If we do not take an active stand on the protection of these amazing birds, we stand a chance of creating yet another ?dinosaur,? available to our children only through history and science books.