(Klinowska, 1994) But the field and its researches are still developing and remain vague. However, what remains apparent and factual is how the human species seems to connect with the dolphins. Bottlenose dolphins are the most studied species. They measure an average of 2. 5 to 2. 7m. They also weigh an average of 190 and 260 kg. Habitat variations evolve into differences in body size and skull dimensions. Smaller body size is evident in coastal ecotypes while large body sizes are found in offshore ecotypes. Bottlenose dolphins found in the Pacific measure 12 ft.
and weight about 1,000 lbs while those found in the Medittarean grows longer than 12 ft. Males grow longer than females and become heavier, considerably. Like humans, the females are observed to grow at faster rate during their juvenile ages as compared to male dolphins. Figure 1. Dolphin body parts. Source: Seaworld 2002 The dolphins are known to have sleek, streamlined body shapes. These body form easily adapt to water habitats. Basic to dolphins body form are the rostrum, eye, blowhole, dorsal fin, pectoral flipper and tail fluke as illustrated below.
Figure 2. Dolphin internal body parts. Source www. crystalinks. com Dolphins are mammals. They breathe air, are warm blooded, give live birth to babies and nurse their young. As seen in the illustration above, these mammals breathe. The warm blooded creatures also give live birth to offsprings and nurse their young like humans. By 5 to 12 years, females become sexually mature while at 9 to 13 years males are able begin reproducing. Springtime is the usual mating season. Gestation follows to 11 till 12 months. Each female gives birth to a single calf, tail first.
Minutes after birth, calves immediately swim and breathe. Females nurse their babies up to 18 months. During these months mother and calf remain close for protection and for getting the aerodynamic effect of the mothers swimming to the calf. Dolphins are aquatic fast swimming mammals. 57 species are recorded. The largest Dolphin is known as the Killer Whale named Orca. The Orca is most fearsome predator. It fears no sharks. Not even other Orcas. It doesnt even fear going out of the water by the beach for a little while enough to snap at helpless baby sea lions for its meal.
The belly of the dolphins appear pinkish or faded white but dolphins may come in gray, gray-green, gray-brown or spotted on the back. Its coloration abilities are part of their camouflage that help dolphins conceal themselves from either predators or prey. Like shark, their dark backs when seen from above blend with the dark water and when they are seen from below, their white bellyies blend with the light from the sky. Migrating creatures, dolphins migrate due to variations in water temperature.
As food fish goes on their migrating patterns, so do dolphins feeding habits. Dolphins found in the coastal waters at higher latitudes migrate seasonally traveling far distances towards the south during winter season. Dolphins in warmer waters migrate less extensively showing movements in only within localized areas. Other coastal dolphins swim among limited home ranges where individuals or small groups have been sited to regularly move about during the whole day. Home ranges of dolphins groups remain to overlap at some points.
It is this migration patterns that has enabled tourism industries to take advantage of in the objective of earning from eco tours at the same time increasing awareness of environmental protection efforts for the dolphin and the whole marine life in general. Off the many coasts in the Philippines for example, many dolphin and whale watching tourist attraction bring tourists, students and scientists to areas where the dolphins pass by for local feeding areas. The wild dolphins of Panama City have been used by tourism as an attraction for close to 20 years.
Their charisma, abundance and accessibility have made them a prime target for numerous tour operators. In our area, most travel magazines, tour brochures and promotion pamphlets use dolphin images to market their services. Several tour businesses are very well organized to sell the wild dolphins of Panama City, who have become a valuable resource for the community, much like our areas fish stock is an asset for the sports fishing industry. (Water Planet, 2001) Once hunted for commercial purpose, approximately 4.
8 million dolphins between 1959 to 1972, were also accidentally trapped in tuna nets. They would not escape and eventually drown because they cannot swim for air. The sourcing of alternative oil extracts that can be used for lubrication, dolphins hunting has been banned. Animal rights activists continue to pressure consumers worldwide to stop buying tuna from coming from companies that do not consciously protect dolphins or any sea creatures. Laws such as the Marine Mammal Protection Act of 1972 ensures that dolphins used in shows or zoos are not exploited.
The National Marine Fisheries Service is the agency that regulates this law. The dolphins feed on fish and squid. At each day, it feeds almost one third of food of its weight. They are very swift and can outrun their prey. Dolphins are superbly streamlined and can sustain speeds of up to 30 km/h (up to 19 mph), with bursts of more than 40 km/h (more than 25 mph). Their lungs, which are adapted to resist the physical problems created for many animals by rapid changes in pressure, enable them to dive to depths of more than 300 m (more than 1000 ft).
(Encarta, 2006) Most dolphins have 200 to 250 sharp razor teeth. The dolphins usually follow schools of fish and hunt together. Pacific white sided dolphins travel in large groups while bottle nosed dolphins aggregate in less numbers. The order of Cetacea is composed of whales, dolphins and porpoises. These mammals although need air and have lungs are highly adapted to water. They actually spend most of their lives underwater. Clicking sounds and whistles are constantly emitted by dolphins. These short pulses come from the below the blowhole.
The pulses are used to resonate objects and become a useful gadget for echolocation. The melon is found above the forehead and is used as an acoustic lens. The echolocation of the dolphin is very much similar to the bat. The pulses are used to locate food while the whistles are used to communicate danger, sexual excitement and other possible emotional states that are currently being studied in many research facilities. The ability of dolphins exemplified in learning and performing stunts in captivity has made human continually interested in these mammals.
Dolphin show that they can communicate with other dolphins. They can approximate human sounds and react to certain words that are used to command tasks in shows. Scientists believe and hope that the dolphins may be able to communicate with human beings once science fully understands how to develop the dolphins learning abilities. Although there are evidences to support that the intelligence level of dolphins can encompass problem solving abilities, the communication system of dolphins do not yet approximate the complexities of a true language.
Either way, humans need to co-exist with dolphins along with other marine species and living things in general. Their continued existence ensures the survival of the human species as well. Until man projects his data and studies on dolphins in the light of conservation instead of consumption, the dolphins will always be an endangered species. References: Crytal, Ellie, 2006. Dolphins. April 15, 2002. http://www. crystalinks. com/index. html Encarta, 2006. Dolphins. Encyclopedia Article. April 15, 2002. http://uk. encarta. msn.
com/encyclopedia_761552786/Dolphin. html Gaskin, D. E. (1982). The Ecology of Whales and Dolphins. Honeymoon, London. Klinowska, Margaret. 1994. Brains, Behaviour and Intelligence in Cetaceans (Whales, Dolphins and Porpoises) High North publication 11 Essays on Whales and Man, second edition, 26 Sept. 1994 Seaworld, 2002. Habitat and Distribution. April 15, 2002. http://www. buschgardens. org/infobooks/Bottlenose/habdisdol. html Water Planet, 2001. Research projects on a dolphin population. April 15, 2002. http://www. waterplanetusa. com/research. htm