Adaptation of the Fennec Fox to the Desert

Adaptation of the Fennec Fox to the Desert How the fennec fox (Vulpes zedra) has adapted to the desert environment The fennec fox is the smallest member of the Vulpes genus (formally in the Fennecus genus) only weighing 2.2 – 3.3 lbs. It is highly distinguishable by its huge ears measuring 6 inches, and a body length of up to 16 inches. It is a nocturnal animal that stays in its burrow and rests for the hottest parts of the day (The Nature of Wildworks, 2014.). It is a highly social animal and lives in family groups of up to 10 individuals (Fox, 1975). Formerly in the fennecus genus, it was later re-classified into the Vulpes genus which is the main taxonomic group of all foxes. Its geographical range is the north Sahara and Arabian deserts. The fox is under decline due to being hunted for the fur and pet trade which has had significant impacts on the wild species (The Nature of Wildworks, 2014.) The fennec fox has many adaptions to living in a desert environment. These can be broken down into 3 categories; Morphological, Physiological and Behavioural. Morphological Morphological adaptions are changes in the animal’s structure that helps it adapt to the extreme conditions of the Saharan dessert. One of the most significant morphological adaptations that the fennec possesses is its large ears. The ears are used to dissipate heat and maintain the optimum body temperature of the animal (Wathen, et al., 1971). The ear needs to be large to have a large surface area for heat dissipation. The statement that these actually cool the animal is not entirely true, they do not cool the animal and lower its body temperature, but instead maintain the optimum body temperature. In a study on jack rabbits, the ears were found to dissipate nearly 100% of all metabolic heat at air temperatures of only 30Â °C (Wathen, et al., 1971). This is only possible if the temperature of the fox is above the environmental temperature. The ears also play a critical role in nocturnal hunting (Wathen, et al., 1971). The large pinnae of the ear help direct low level sound i nto the ear which gives the fennec acute hearing allowing directional hearing (Ewer, 1973). This is a key adaption for hunting at night due to the low light levels, thus giving the fennec the ability to hunt effectively at night using sound as well as excellent night vision. The feet of the fennec are adapted to walking on the hot sand by having hairs covering their fleshy foot pads (Ewer, 1973). This prevents the foot from actually touching the scolding sand and will prevent injury when the fox is digging its burrow and walking across the hot dessert floor. The front paws are specially designed for digging burrows which the fennecs live and breeds in (Ewer, 1973). The fur of the fennec like most dessert animals is vital to coping with desert life. Not only does this insulate the animal, but studies have shown that the light fur of the animal can also reflect the solar radiation, therefore lessening the impact and reducing the heat load on the animal (Dawson Brown, 1970). This is most true in the fennec fox due to its sandy coloured or sometimes white fur. Meanwhile the thickness of the fur is a protection from the solar radiation of the skin. By creating this barrier, the fur prevents any damage to the skin from direct solar radiation. This is because the fur, as said before, partially reflects the solar radiation while the thicker deeper fur absorbs the heat (Dawson Brown, 1970). The heat absorption also helps the fox survive the freezing dessert nights while it feeds, by preventing the fennecs core body temperature from dropping too low. Physiological Physiological adaptions are changes in the animal’s system processes to enable them to adapt to changes in the environment. These changes enable the fennec to adapt to the extreme environment of the North African deserts. Carnivores, just as the fennec, are found in a number of deserts around the world. A major challenge that these organisms face is the replenishment of water. The fennec gains its water requirements solely from having mostly a carnivorous diet. The fennec, by eating alone, can maintain its water balance for over 100 days without having to drink (Vaughn, et al., 2000). This is done by the fennec having very concentrated urine that uses the least amount of water possible to function. This conserves a vast amount of water and coupled with its very low evaporate loss. Therefore it rivals small desert rodents in its water conservation (Vaughn, et al., 2000). This relates to selective predation and an ability to feed on a wide variety of food stuffs, while being abl e to become more economical with its metabolic water. The adaption of having a low basal metabolic rate is crucial to survival in dessert conditions. The fennec is no exception to this; it has one of the lowest BMRs of all Vulpes species of 60.7 percent (Golightly Ohmart, 1983). This means at rest the fox only uses the minimal amount of water needed to survive. This adaption allows a minimalized endogenous heat load which conserves metabolic water. This saving of water becomes critical in the desert due to the low precipitation levels and therefore having the adaptation of a low BMR helps maintain any dietary water acquired and conserves it. Behavioural Behavioural adaptations are changes in the animals conduct help it survive in a certain environment. Previously, little was known about the fennec foxes diet. It was previously thought that they were primarily insectivores and had barely any variety in their diet. However, a new study has shown that they are actually opportunistic feeders with food items being mostly insects, but it also feeds on small mammals and even plant material (Brahmi, et al., 2012). The study also shows that locality and abundance of food can also change the feeding behaviour of the fennec. This adaption is critical to the survival of any dessert animals. The ability to feed on many different food sources opens up many more niches and availability for the animal to survive and feed (Brahmi, et al., 2012). Panting is an adaption that requires short shallow respiration and is solely used in heat dissipation. Panting makes use of evaporative cooling of the mouth, lung and nasal mucosa. This is a very effective way of cooling down without having to sweat. This main advantage over sweating is that in sweating there is salt loss, while in panting there is not (Vaughn, et al., 2000). This is key to the survival of the fennec because of the shortage of food; therefore the fennec cannot regain the salt quicker than the animal uses up. If the fennec sweated this could become a huge problem, so it has overcome this problem by making use of the more efficient panting for heat dissipation (Vaughn, et al., 2000). Fennec fox families live and thrive in burrows; these help counteract the daily effects of high temperature and low humidity of the desert days. They provide shelter from sun exposure and the highest temperatures of the dessert day. A study in tortoises shows that burrows provide a great place to refuge in a desert environment. The study showed that the burrow at 10:00 -12:00 hrs had much higher humidity and lower temperature than the external environment (Bulova, 2002). This lowers the total evaporate water loss which helps the animal, in this case the fennec, conserve metabolic water, which is key to desert survival. Fennecs therefore make use of the much more stable and milder environment inside the burrow. This helps shelter the fennec from extreme conditions and helps conserve water. This is due to the soil temperature maintaining stability no matter what the conditions are outside. The burrow controls the internal environment due to the thermal insulating properties of the soil (Reichman Smith, 1990). Therefore the burrow is cooler during the day and warmer during the freezing desert nights. Conclusion To conclude there are many adaptations the fennec has; may that be morphological, physiological and behavioural. The adaptations are a necessity to survive in such an extreme climate, such as the dessert; with high heat loads during the day, freezing temperatures in the night, food and water sources are scarce. The adaptions that the fennec utilises all boil down to protection from the incredible temperature change in the dessert, by having large ears to dissipate heat and fur that can reflect but also absorb the heat. This gives protection from solar radiation during the day, and insulation during the night. The other main reason for having many complex adaptations is to conserve water. The fennec’s metabolic water level is maintained by having a low BMR which uses less water in metabolic activity at rest, and also the concentrated urine which reduces the loss of water via waste. In my mind the fennec fox is perfectly adapted to cope with the extremes of desert life, by contr olling its water conservation and body temperature. Word count: 1,508 References: Brahmi, K. et al., 2012. First quantitative data on the diet of the fennec fox, Vulpes zerda (Canidae, Carnivora), in Algeria. Folia Zoologica, 61(1), pp. 61-70. Bulova, j., 2002. How temperature, humidity, and burrow selection affect evaporative water loss in desert tortoises. Journal Of Thermal Biology, 27(3), pp. 175-189. Dawson, T. Brown, G., 1970. Comparison Of The Insulative AndReflective Properties Of The Fur of Desert Kangaroos. Comparative Biochemistry and Physiology, Volume 37, pp. 23-28. Ewer, R., 1973. The Carnivores. 1st ed. s.l.:weidenfeld and nicolson. Fox, M., 1975. The Wild Canids Their Systematics, Behavioural Ecology and Evolution. 1st ed. s.l.:Litton Educational Publishing, Inc. Golightly, R. Ohmart, R., 1983. Metabolism and body temperature of two desert canids: cototes and kit foxes. Journal of Mammalogy, 64(4), pp. 624-635. The Nature of Wildworks. 2014. The Nature of Wildworks. [ONLINE] Available at: http://www.natureofwildworks.org/species.html#ffox. [Accessed 12 February 2014]. Reichman, O. Smith, S., 1990. Burrows And Burrowing Behavior By Mammals. Current Mammalogy, pp. 197-224. Vaughn, t., Ryan, J. Czaplewski, N., 2000. Mammology. 4th ed. s.l.:Saunders college publishing. Wathen, P., Mitchell, J. Porter, W., 1971. Theoretical and Experimental Studies of Energy Exchange from Jackrabbit Ears and Cylindrically Shaped Appendages. Biophysical Journal, 11(12), pp. 1030-1047. Harvard – Anglia 2008

Internal and external factors effecting the cost position Essay

The increased imports of the European as well as the Japanese make of automobiles in the United States significantly impacted the demand of the automobiles manufactured by the US manufacturers. â€Å"Imports of sub-compact cars from Europe and Japan rose steadily in the 1950s, often as families’ second cars but US manufacturers retained their hold on the lucrative markets for larger vehicles. † (French, 1997, p142) The US manufactures saw their market shrink as the more aware and price conscious consumers shifted to the European and Japanese counter parts for their automobiles, while the US manufacturers were left with making large, excessive fuel consuming vehicles that denoted social status and personal style. Aside from this the increasing prices of crude oil in the international market in the 1970s also significantly changed the demand of the automobiles as depicted by the consumers. â€Å"A crisis in the US car-market developed as a result of sudden unforeseen shifts in the general environment which allowed overseas producers to expand market share rapidly. New car sales faltered in the 1970s and excess capacity increased. At the same time the leap in fuel prices shifted the consumer preference towards smaller, more fuel efficient cars which Japanese and European makers already supplied in their domestic markets and were better able to produce that were the US manufacturers used to making larger, more up-market ‘gas-guzzlers’† (French, 1997, p142) The automobiles of French and Japanese make were smaller, more fuel efficient as well as more stylish yet cheaper than the those manufactured by the big three US automobile manufactures. As a result the consumers opted for purchasing the imported cars instead of those manufactured by the Unites States manufacturers. The recession of the 1970s also further reduced the disposal income and the propensity to save for the people in the United States which made purchasing the imported European and Japanese models of automobiles much more attractive to the consumers instead of opting for those models manufactured by the big three US automobile manufacturers. In the same period the perception of the consumers also significantly changed as was marked by the baby boomer generation and the hippy era. In this period, the consumer became more aware of the environment, the increasing pollution and the contribution that automobiles made towards adding to the pollution levels. As a result the consumers started to look for cheaper alternatives of travel and those which were more environmental friendly that the vehicles manufactured by the big three US automobile manufacturers. The internal factors that contributed to the changing cost position of the Bridgestone Industries, specifically at the plant pertained to the decreasing demand of the US manufactured cars and increased demand for cheaper cars that was reflected un the restricting cost based purchases being made by the big three manufactures form the Bridgestone Industries. As the volume of sales decreased for Bridgestone Industries, along with the margin for profits on sales made due to the rising overhead costs the cost position of the Bridgestone Industries significantly changed to become negative and resulted in the closing of the automotive component and fabrication facility by the Bridgestone Industries. Overhead Burden Rate The Bridgestone Industries had a specific method for determining the overhead burden rate for the products that was proposed and set on an annual basis. â€Å"The budgeted unit costs provided by the plant for the 1987 model year study included overhead (burden) applied to products as a percentage of direct labor dollar cost. The overhead percentage was calculated at the budget time and used throughout the model year to allocate overhead to products using a single overhead pool. The overhead rate used in the study was 435% of direct labor cost† (Patricia & Cooper, 1993) The following table depicts the overhead burden rate for the years starting 1987 through to 1990. Overhead Burden Rate (‘000) 1987 1988 1989 1990 Total Overheads 107,954 109,890 78,157 79,393 Total Direct Labor Dollar Cost 24,682 25,294 13,537 14,102 Overhead Burden Rate 437 434 577 562 The analysis of the overhead burden that was determined for the years, 1987, 1988, 1989 and 1990 showed that the total over heads increased from 1987 to 1988. However in 1989, there was a drop in the overhead level as the muffler exhausts and the oil pan based product lines were merged with the other three product lines. This reduced the overheads significantly. In 1990 however the trend shows that the overheads for the Bridgestone Industries increased again on an annual basis. The direct labor dollar cost showed a similar trend as well reflecting the increasing expenses along with the effect that the closure of the muffler/exhaust and oil pan lines had on the labor cost. The overhead burden rate that was determined pertained to approximately 437 percent in 1987, 434 percent in 1988, 577 percent in 1989 and 562 percent in 1990. The following table depicts the overhead burden shared by the respective product lines at the Bridgestone Industries for the years starting 1987 through to 1990. Overhead Burden Share per Product Line (‘000) Overhead Burden 1987 1988 1989 1990 Fuel Tanks 18,234. 35 18,412. 03 25,490. 37 25,891. 96 Manifolds 25,744. 16 26,184. 35 36,246. 56 36,819. 62 Doors 11,463. 72 11,864. 85 16,420. 07 16,681. 43 Mufflers/Exhausts 24,646. 33 25,050. 44 0 0 Oil Pans 27,865. 45 28,378. 33 0 0 107,954 109,890 78,157 79,393 The overheads shared by the respective product lines also depicted significant change in the years from 1987 to 1990. On average the oil pans product line had the largest overheads allocated to its while the product line for the front and rear doors had the lowest overhead levels for the years 1987 and 1988. When the product lines were merged in 1989, the manifolds product line had the largest level of overheads allocated to it, while the product line for front and rear doors had the lowest level of overheads assigned to it. On a year to year basis, the overhead burden level has decreased by a small gradual percentage over the four years highlighted. This is not due to the fact that the overheads for the company have been decreasing; instead this has occurred due to the fact that the dollar cost of the direct labor has incrementally increased over the four year period as well resulting in the decrease in the overhead burden rate.

Summer Writing Assignment †College Essay

Among all the characters that I have encountered in books and movies, one persona stood out as the one I want to emulate the most. He went by the name Equality 7-2521 from the novel entitled â€Å"Anthem† by Ayn Rand. He appealed me the moment I read the book because he embodied what I am striving to be.His personality was the quintessence of the qualities I needed to be successful. When I read the book, I was utterly impressed by his determination, intelligence, and more importantly, his perseverance as an individual. He has a significant influence on me and I find him a great source of inspiration to struggle harder in the complexities of life.It was during my sophomore year that I read the book â€Å"Anthem.† At that time, I was in a predicament over whether I should concentrate on schooling or finding a part-time job.The reason why I had such qualms was that even I made endeavors to complete my school works properly and attempted to attain high scores, my poor Engli sh proficiency derailed my plans. I was discouraged by the inconsistency of my efforts and grades printed in my report card.The course of things changed when I read â€Å"Anthem.† I was impressed by the characteristics of Equality 7-2521, the protagonist in the novel. The story was set in a fictional world which was dominated by collectivism. Equality 7-2521, who was seeking for self-identification, struggled in a society that rejected individualism in favor of collectivism.Equality 7-2521 discovered a tunnel where he began hiding regularly to conduct scientific experiments. Later on, he invented the light bulb and decided to share his device with the World Council of Scholars, even though he knew the way he came to discover electricity was illegal and sinful. Subsequently, Equality 7-2521's presentation of the light bulb to the World Council of Scholars permanently severed him from society and forced him out on his own.The reason that the World Council of Scholars made this decision was that collectivism does not allow people to think or work individually but jointly. As a result, Equality 7-2521 was exiled yet he did not stop pursuing his goal. He kept studying in the woods and eventually discovered the meaning of individualism and the word â€Å"I.†As I read the book thoroughly, I realized the qualities that I must possess in order to achieve my ambitions. Equality 7-2521 had a worse situation than mine, but by the virtue of his positive attributes, he successfully pulled off his discovery. He believed in individualism and rejected the collectivist society around him. He was insightful, perseverant, truth-seeking, resolute, and intelligent. He was deeply curious and desired freedom to explore and think, and he was unafraid of the society of mindless drones around him.Equality 7-2521 represented the superiority of a singular intellect to the homogeneity of the masses, who could not think of themselves and were indistinguishable from one another . I plan to get a high score as well. I believe I could reach my aspirations if I exemplify the qualities that Equality 7-2521 had. The strong and firm character Equality 7-2521 held inspired me every time I face a dilemma in real life.Equality 7-2521’s story assured me that nothing is impossible and that I can succeed too even in my simple but unrelenting ways. Along this line, I should stay focused on my work and studies, and possibly make a significant improvement in the coming marking period.He had a tremendous impact on my personality, not only in my study habits, but also in the determination to confront difficulties. Whoever and whatever I am now, I owe it for the most part to Equality 7-2521 for transforming me to the kind of person I never imagined I could ever be. Life indeed is like a roller coaster with ups and downs to render it more interesting and breathtaking. And above all, what is of the essence is that Equality 7-2521 indirectly made me complete and unexpec tedly happy as well.

The Effects Of Prenatal Hormones On The Developing Fetus

Why some people are attracted to members of their own sex whereas others are attracted to members of the opposite sex is no known cause or reason. There is belief to it possible contributing from genetics, hormonal and the environmental influences. One study stated that there is a 50 percent chance that if one identical twin is homosexual or bisexual, the other twin is too. Similar findings lead that some researchers estimate that sexual orientation is 30 to 70 percent genetic (Mustanski, Chivers, Bailey, 2002). Another research suggests that sexual orientation is impacted by a gene or genes found on the X chromosome. Though genetic tendencies for homosexuality may be passed from mothers to their children (Rahman Wilson, 2003). During human evolution, homosexuality was developed to minimize competition between males for a limited number of potential female mates (Schulling, 2004). A different possibility is that prenatal hormone levels influence the developing fetus (Levay, 2011). 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