Dolphins
Dolphins are mammals closely related to whales and porpoises. Dolphins have a powerful and streamlined body. They are found in all seas and oceans.
Dolphins can be told apart from porpoises by their nose, which is beaklike, and also their conical teeth. Porpoises have a flatter nose, sharper teeth, and a more solid body.
There are 32 known species of dolphins. The bottle-nosed dolphin is often the species used in aquatic shows. The common dolphin inspired many
Mediterranean folk lores. Both of the dolphins above appear in open waters, usually around cruise ships. They like to show off around the boat.
There are also freshwater dolphins that live in rivers of Asia and South
America. The Buffeo dolphin has been spotted up to 1250 miles up he Amazon River.
The buffeo is the smallest of all dolphins averaging about 4 feet. The bottlenose is closer to 10 feet. The killer whale, which is also considered a dolphin, can grow to be 30 feet long. The pilot whale is also considered a dolphin. Dolphins were once hunted by commercial boats for the small amount of oil that can be extracted from their body. This oil is used to lubricate small parts in watches. Cheaper oils have been found, so dolphins are not hunted for this reason anymore. Dolphins can be caught in tuna nets by accident. Since dolphins have to breath at the surface they drown in tuna nets. It is estimated that 4.8 million dolphins were killed in tuna nets from 1959 to 1972. Under pressure from animal rights activists tuna consumers will not accept tuna from canners that do not protect dolphins. Animal rights activists also believe that dolphins shouldn't be in captivity for use in aquatic shows.
Dolphins eat a lot of food in a day, usually about one third of their body weight. A dolphin's diet consists of mostly fish and squid. Dolphins can swim very fast, so they are able to easily catch their food. The dolphin has 200 to 250 sharp teeth. Dolphins follow schools of fish in groups. The Pacific white-sided species is estimated to travel in groups with tens of thousands of members, while on the other hand bottlenose dolphins travel in groups that contain only a few members.
Dolphin, like whales, breathe through a blowhole in the top of their head. While traveling dolphins break the surface once every two minutes. When dolphins exhale water is sometimes thrown from the blowhole. After exhaling the dolphins inhale and disappear into the ocean. A dolphins lungs are adapted to resist the physical problems that are caused by quick changes in pressure.
One of the most common dolphins that are found in southern California is the bottlenose dolphin (Kelly). The bottlenose dolphin is mainly found in coastal waters between 45 degrees north and 45 degrees south, also in Northern Europe waters. It is believed that there are two types of bottlenose dolphin regional wise: oceanic form and coastal form. This species is studied the most by biologists (Jefferson). The coastal population lives in fairly open groups with twenty or less in a pod, some groups are found to contain more in open ocean. It is not uncommon for these species to interact and breed with other species, as would a human interact with other diverse humans. The dolphins feeding behavior is adapted to the availability of resources. They sometimes are known to work together to catch fish from large schools, they also trail behind large fishing boats to catch what falls behind (Leatherwood).
However, they began to go extinct when North America merged lands with the Southern counterparts, allowing placentals to move into South America and largely outcompete them (Moskowitz ,2010). Placentals now occupy one of the widest range of environments from marine to terrestrial. In order to thrive in the environments they are subjected to, eutherians have evolved various structural adaptations. They vary in size from shrews to whales. Being housed largely in tropical Asia, shrews (Eulipotyphla) are terrestrially adapted to dig burrows to hide from predators and forage for food with their reduced body size. In contrast, whales (cetacea) are the largest creatures dominating deep oceans. With its enlarged body size, its stomach is able to contain one tonne of krill for feeding (WWF, 2016). Contrastingly, the marsupials like kangaroos and koalas, as well as monotremes including the duck billed platypus and spiny anteater, all remained and possesses similar body sizes, completely lacking diversity compared to the
Orcinus orca is the scientific name for the massive marine mammal. Orcas are not rare, but have declining numbers in some areas (Martin.) Orcas are found from the Artic Ocean to the Antartic Ocean. (Britannica) They belong to the Delphinidae, or dolphin family, which is the largest of their species. Female orcas grow to be at the most 15 feet, and weigh up to 4 tons, but the males can grow as large as 20-30 feet, and weight up to 8 tons. (Martin) The color of the orca is white in some spots, black on the majority of the body, and gray just behind the dorsal fin. It is white on the chin, belly and the eye. The white patch above the eye is usually mistaken for the eye, and may confuse their prey, but acts as a camouflage for the eye. The name “killer whale” makes people tend to believe that this is a viscious man-eating mammal, yet it is one of the most shrewd, docile and playful species of the marine mammals. The orca is sexually mature at 10-15 years of age, much like humans, which is 12-13 years of age. They tend to mate year round, and is able to have a calf every two years. It is interesting to know that lactation of the mother lasts 12 or more months (Wynne.) The life expectancy of orcas is 45-50 years of age.
Orca whales are the largest members of the dolphin family. Orcas are very curious creatures, they like to sky hop, which is when they poke their heads out of the water and look around, and they can also dive to as much as a hundred feet. These social animals live in pods and stay with them for their whole lives. They are so family oriented that they can may sleep together in a tight circle and have synchronized breathing. Orcas can grow up to thirty-two feet and can weigh nine tons. They typically eat five percent of their body weight and are amazing hunters. The lifespan of an orca in their natural habitat is about fifty years. This lifestyle for them is wonderful because they can swim as far as they want to and are free. Orcas should not be held captive because the capture process is dangerous, it is not good for their health, and their trainers are at risk. Free Willy. Dir Simon Wincer. 1993.Video. Warner Bros Home Video
They are the second smartest animal in the world. They nurture their young for most of their lives. They also socialise with any creature, unless they show signs of harm. Dolphins make very popular playmates and will come up to humans for almost anything. They rely on each other to live. They learn quickly and communicate well with one another. God designed dolphins with unique physical features and behaviors in order to glorify Him.
Bottlenose dolphins became part of a United States Navy program in 1959 for the purpose of conducting scientific research into their sonar and hydrodynamics in hopes of getting design ideas for submarines, ship hulls and weapons. It was discovered dolphins hear and navigate in the water by using their natural sonar, which happened to be more precise than most fabricated sonar systems. In the mid-sixties, Navy dolphins were used as mail carriers to underwater laboratories in their home of San Diego, California.
A large part of the whale's diet is made up of small shrimp-like animals called krill, which the animal strains with its plates of baleen. In order to get enough of these small creatures to eat, a blue whale has to filter large amounts of water. Folds of skin on its throat expand like an accordion to allow the whale to gulp in as much as 64,600 liters (17,000 gal) of water at one time. The whale then pushes its tongue (which can be as large as a Volkswagen) to the roof of its mouth in order to force out the water. Food is caught in the hairs of the baleen and swallowed. A blue whale weighing 75 to 80 tons eats about 4 tons of krill per day during the feeding season.
The book In the Heart of the Sea: The Tragedy of the Whaleship Essex by Nathaniel Philbrick, is an inspiring story about an Essex from Nantucket, getting attacked by a eighty-five ton sperm whale miles deep out in the ocean. In these times, going on any ocean expedition had its precautions. While much focus on food, drinking water, medication and a method to cure illness, the most overlooked impairment was the creatures of the ocean. While the men of this vessel left the docks as predators, the survivors of the ninety- three-day journey on three small harpoon boats came back as prey. This story gives a great depiction of the potential of the sperm whale as well as the devastation that they can bring.
Cetaceans are thought to be some of the most intelligent species on this planet. Popular culture has embraced the idea of cetacean intelligence with shows such as the 1960s hit TV series Flipper, where a dolphin is used to help fight crime. In his comedic science fiction novels, the Hitchhiker’s Guide to the Galaxy, author Douglas Adams suggests that dolphins are the second most intelligent creatures on Earth, behind mice and above humans. Although most scientists would probably argue that humans are the most intelligent species, the behavior and brain size of dolphins and other cetaceans suggests that they too are intelligent. This paper will briefly describe the reason some scientists believe cetaceans are intelligent species and then give examples of scientific studies, which suggest cetacean intelligence. Since bottlenose dolphins and orcas are the most widely studied cetaceans, the survey of field studies will primarily focus on these two species. At the end, this paper provides an argument of why some scientists discredit the high degree of cetacean intelligence.
Blue whales tend to feed on krills in cold water at high latitudes during the summer time (WWF). On other hand during
Orcas, or killer whales are majestic giants of the sea. They are actually the largest type of dolphin. They have long black bodies with distinct white patches near their eyes. A killer whale can be up to 32 feet or more in length, and weigh up to 12,000 pounds. Females are a bit smaller, but live longer (Gorman). The name “killer whale” apparently came not because it is a vicious whale, but because it preys on whales. They do not have any natural predators, and they are considered the “top dog” of the ocean. Not even the great white shark stands a chance against these superb killers. “Unlike sharks, killer whales are cautious hunters, sometimes spending hours harassing a 1,000-pound sea lion so it can easily be drowned” (Francis). Orcas use many hunting tactics that are unique to their species, which is what makes them invincible.
Elephants should not be killed because they are one of the main reasons that people visit the foreign land of Africa. Africa is incredibly hot and is not the most intriguing place to go on your vacation. If there were no elephants the amount of tourists would significantly decrease. Twenty eight percent of all tourist come to see the elephants. In the movie “Ivory Wars” the narrator says “ One of the few attractions for tourists is the African elephants that run wild and free across the vast plains of the continent of Africa.” When the amount of tourists decrease so does the money that they pay to see the elephants at a safari. Africa is obviously does not have the strongest economy to begin with and without the elephants to bring in tourists the continent of Africa will fall apart. Elephants are exotic and amazing to see, and without them would there really be a reason to visit Africa?
The Humpback Whale, Megaptera novaeangliae, is part of the marine mammals group. They are found in oceans all over the world, they live in open waters. Even though they are mammals, they do not live on land (Monterey Bay Aquarium). Humpback whales are known for their magical song that can travel great distances. These gentle giants are omnivores, their main diet is krill. They are mostly found near coastlines feeding on tiny shrimp-like krill, plankton and small fish. Humpbacks migrate annually from summer feeding grounds near the poles to warmer winter breeding water closer to the Equator. Humpback whales are powerful swimmers, and they use their massive tail fin, called a fluke to propel themselves through or even out of the water! Mothers and their young swim close together, often touching one another with their flippers with what appears to be gestures of affection. Even though it takes more than one year for a humpback whale to grow fully, mother whales leave them after one year (National Geographic).
...r. Even though they live in the ocean all their life and also amusement parks, dolphins are mammals, not fish. That makes them very intersting animals because of all the charactics that they have that people would have never known about. Dolphins are by far the most intelligant marine mammals in the ocean.
Did you know in the world there are more than 90 species of whales, dolphins, and porpoises? (WDC) The dolphin is a very important animal to the ocean and there are many different types to discover. In order to learn about dolphins, it is important to discuss where they live, their appearance, and what they eat. Some helpful words to understand are “dorsal fin”, a dorsal fin is the top pointed fin on the dolphins back, “flippers”, a flipper is a flat fin that dolphins use to swim, and “echolocation” is a tool dolphins use to find food by sounds bouncing off of objects (dictionary.com).