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Endangered polar bears due to global warming
Polar bears climate change effects
Polar bears climate change effects
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The fossil record demonstrates that mammals re-entered the marine realm on at least seven separate occasions. Five of these clades are still extant, whereas two are extinct. the degree to which each of these clades has adopted an aquatic lifestyle. Both Cetacea and Sirenia originated at about the same time and were fully aquatic by the end of the Eocene epoch. Each of these evolutionary histories is different from the others based on which changes in each anatomical system occurred. Despite this finding, they all have one change in common at the very beginning. The earliest members of each of these clades of marine mammals show adaptations of the feeding apparatus for feeding in water. Orcinus Orcas, more commonly known as killer whales, are the most widely distributed cetacean species in the world. Everything about them describes the ultimate predator. In actuality, they are dolphins and not whales as their name suggests. Nearly everything about the Orcinus Orca shows some type of mechanism for adaptation. Their characteristic fusiform body shape prevents drag and is designed for a swift and graceful glide through the water with a swimming potential of nearly 30 mph. In addition to their streamlined bodies, the Orcinus orca's forelimbs are adapted for swimming. An Orca uses its two paddle like pectoral flippers to steer. These flippers closely resemble the major bones of the forelimbs of land mammals, albeit modified into a paddle shape to fit their aquatic lifestyle. The tail flukes are boneless, dense connective tissue, and help the Orca stop. A dense triangular dorsal fin helps the Orca maintain stability as it propels at high speeds, though it isn’t crucial. Living in mostly frigid waters, the endothermic Orcas need to main... ... middle of paper ... ... survivor of both its family and genus. As their prey are aquatic, polar bears are excellent swimmers, even using only its front limbs, an aquatic adaptation found in no other four-legged mammal. Global warming poses a threat to their icy arctic habitat but maybe it is part of the transition from a terrestrial to marine habitat. They just might adapt into the water again. Also, another clue that something might happen is that they spend most of their time in the water feeding. This is no great surprise, because a great deal of mammalian evolution has been linked to changes in feeding ecology. The earliest representatives of each clade all show morphological features that indicate they were feeding while in the water, suggesting that feeding ecology is a key factor in the evolution of marine mammals. (Uhen M.D. 2007) Works Cited THE ANATOMICAL RECORD Uhen (2007)
Imagine yourself living in a bathtub for 25 years and you could do absolutely nothing about it. Wild orcas, better known as killer whales, have been captured to entertain audiences worldwide at aquariums. The most popular location is Sea World. Growing up in Miami, I could not control my excitement when it came time to go visit Lolita, the killer whale at the Miami Seaquarium. To be able to see such an amazing creature right in front of me was mind blowing.
For 50 years SeaWorld has entertained park guests with numerous stunts involving the majestic sea creature, the orca, also referred to as the killer whale, and their human trainers. What the on-lookers don’t see at these shows is what goes on behind the scenes: how the whales got there in the first place, and the conditions in which they are housed.
The Arctic region is home to a variety of valuable animals and plants, including polar bear, seal, and so on. The ecosystem of the Arctic region is fragile because these animals are evolved to live in extreme conditions. With the climate change, many animals are endangered. Ice is the habitat of polar animals because they have to rely on sea ices for resting, food, and reproduction. With the climate change and the decrease of sea ice, the number of polar animals is decreasing and their health is threatened. For example, the average weight of female polar bears in 1980 was about 650 pounds, but the number reduced to about 500 pounds in 2004 (Djoghlaf 15). The earlier breakup and later condensation of sea ice shortens the hunting season of polar bears. Polar bears mainly feed on seals that indwell icy land. The melting ice reduces the number of seals and food intake of polar bears. In addition, polar bears are used to living in ice caves. The rising temperature causes the collapse of ice caves, which can kill baby bears. The climate change is negatively affecting the biodiversity in the region and will definitely harm the ecosystem
The background of this article gives information that is necessary to understand the experiment. The shape of the pelvic girdle is an appropriate predictor of both phylogeny and movement in terrestrial vertebrates. However, in marine vertebrates, the gravitational forces typically applied to terrestrial pelvic girdles are not there and therefore have little impact on the shape of the girdle. Pelvic girdles of fish are generally not attached to the vertebrae and primarily are used as a place for muscles to attach and supporting of the fins. The authors discuss how in many cases the pelvic girdle could be removed and not result in any complications. However, there are some marine vertebrates that are capable of bottom walking on the ocean floor with their fins. In batoids, the pelvic fins are used for walking, which is when pelvic fins move in an alternating fashion, or punting, when both pelvic fins move at the same time. There is also augmented punting; this is when the vertebrate uses both the pectoral fins and the pelvic fins to generate more thrust, this action decreases the forces on the pelvic fins during a punt. While this locomotion would
Scientists had some idea to the evolutionary process of whales. “It has always been clear that aquatic cetaceans must have evolved from terrestrial mammals and returned to the water, and the forelimbs of recent cetaceans still have the same general pattern as that of land mammals.” (Walking with Whales) It was known fact that land mammals and whales were related. However, the change from ancient whales to modern whales is drastic.
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
Jefferson, T. A, M. A. Webber, and R. L. Pitman. (2008). Marine Mammals of the World, A Comprehensive Guide to their Identification. Amsterdam, Elsevier. p. 241-244.
Out of an Ice Age emerged one of our most majestic creatures in the world the polar bear. From its brown bear ancestry, the predator evolved to be a master of a harsh and unwelcoming ice kingdom. Intelligent, adaptable and fierce, the polar bear learned how to survive in a place that offers few comforts to any creature. But now that very environment is in flux. And so is the polar bear’s fate (Nature). Polar Bears are very different from other bears. Polar bears are very large bears compared to Black bears. Polar bears weigh anywhere between 330-1700lbs and Black bears weigh anywhere between 150-600lbs. They have strong legs with large, flattened feet with some webbing between their toes that help with walking on ice and swimming. The wide paws prevent sea ice from breaking by distributing weight while walking. Their paws allow them to pull a 600 pound seal out of its breathing hole (Rosing, 20). The webbed feet results in making polar bears, unlike other bear species to be considered as marine mammals along with seals, sea lions, walruses, whales and dolphins (Polar Bear). According to Rosing Polar bears are excellent swimmers and have been known to swim up to six miles an hour and as far as 60 miles at a stretch. The bears paddle with their front feet and steer with their back feet. They often overheat. Sometimes they venture into the waters just to cool off. When a bear climbs on an ice floe, it shakes itself off because it is trying to prevent ice from forming on its fur (22-23). Because of climate change and hunting of polar bears are now becoming an endangered species which is affecting the food chain. We can fix this by going green, banning polar bear hunting and keep creating these new hybrid bears that are mixed with griz...
The origin of modern day whales, a mystery that has puzzled paleontologists for years, may have just been solved with the discovery of an ankle bone. This discovery might sound simple and unimportant, but the bones of these ancient animals hold many unanswered questions and provide solid proof of origin and behavior. The relationship between whales and other animals has proven to be difficult because whales are warm-blooded, like humans, yet they live in the sea. The fact that they are warm-blooded suggests that they are related to some type of land animal. However, the questions of exactly which animal, and how whales evolved from land to water, have remained unanswered until now.
Orcas, commonly known as killer whales, are actually the largest member of the dolphin family. They were given the name “killer whale” by sailors who often observed them attacking and killing seals, sea lions, walruses, penguins, dolphins, polar bears and even other whales (Orcas).
To begin with, the melting of polar ice caps has caused polar bears to swim long distances. According to Bryan Walsh of TIME Magazine the melting of the ice caps have caused polar bears especially the young cubs to swim longer distances which has caused a “ forty-five percent mortality rate” (Walsh). In the article Walsh, writes about a study that showed that younger cubs because of low fat and strength were more likely to die due to the long di...
One of the previous papers in English class required the class to pick a paper to explore, this question will be concentrated on further in the synthesis essay. What evidence do scientist have to prove that prehistoric sharks existed? The reason behind picking this question wasn’t just to find proof that these monsters swam the seas, but to learn more about them from different resources. One of the resources that were used was a chapter in Angelo Mojetta’s book Sharks, called “ The Birth Of A Legend”. The other resource that was used for information was an article in Discovery Channels website called “ Prehistoric Sharks”. Sharks and Discovery Channel are the two resources that led to many other questions about their different, and similar views on prehistoric sharks existence.
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.
The Order Cetacea is one of the most distinctive and highly specialized groups of mammals. Over the course of evolutionary history, cetaceans have become adapted to surviving and prospering in a vast aquatic environment. One of the most important obstacles they have overcome is the ability to be obligate ocean dwellers while still breathing oxygen. Cetaceans are able to remain underwater for extended periods of time, returning only to the surface to exhale. Diving beneath the surface is an essential component of life for these species since almost all of their food sources are found under the surface of the ocean.