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Toothed Whales
The toothed whales (also called odontocetes, systematic name Odontoceti) are a parvorder of cetaceans that includes dolphins, porpoises, and all other whales possessing teeth, such as the beaked whales and sperm whales. Seventy-three species of toothed whales are described. They are one of two living groups of cetaceans, the other being the baleen whales (Mysticeti), which have baleen instead of teeth. The two groups are thought to have diverged around 34 million years ago (mya). Toothed whales range in size from the and vaquita to the and sperm whale. Several species of odontocetes exhibit sexual dimorphism, in that there are size or other morphological differences between females and males. They have streamlined bodies and two limbs that are modified into flippers. Some can travel at up to 20 knots. Odontocetes have conical teeth designed for catching fish or squid. They have well-developed hearing, that is well adapted for both air and water, so much so that some can surviv ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Early Oligocene
The Rupelian is, in the geologic timescale, the older of two ages or the lower of two stages of the Oligocene Epoch/ Series. It spans the time between . It is preceded by the Priabonian Stage (part of the Eocene) and is followed by the Chattian Stage. Name The stage is named after the small river Rupel in Belgium, a tributary to the Scheldt. The Belgian Rupel Group derives its name from the same source. The name Rupelian was introduced in scientific literature by Belgian geologist André Hubert Dumont in 1850. The separation between the group and the stage was made in the second half of the 20th century, when stratigraphers saw the need to distinguish between lithostratigraphic and chronostratigraphic names. Stratigraphic definition The base of the Rupelian Stage (which is also the base of the Oligocene Series) is at the extinction of the foraminiferan genus '' Hantkenina''. An official GSSP for the base of the Rupelian has been assigned in 1992 ( Massignano, Italy). The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vaquita
The vaquita ( ; ''Phocoena sinus'') is a species of porpoise endemic to the northern end of the Gulf of California in Baja California, Mexico. Averaging (females) or (males) in length, it is the smallest of all living cetaceans. The species is currently on the brink of extinction, and currently listed as Critically Endangered by the IUCN Red List; the steep decline in abundance is primarily due to bycatch in gillnets from the illegal totoaba fishery. Taxonomy The vaquita was defined as a species by two zoologists, Kenneth S. Norris and William N. McFarland, in 1958 after studying the morphology of skull specimens found on the beach. It was not until nearly thirty years later, in 1985, that fresh specimens allowed scientists to describe their external appearance fully. The genus ''Phocoena'' comprises four species of porpoise, most of which inhabit coastal waters (the spectacled porpoise is more oceanic). The vaquita is most closely related to Burmeister's porpoise (''Ph ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
International Union For Conservation Of Nature
The International Union for Conservation of Nature (IUCN; officially International Union for Conservation of Nature and Natural Resources) is an international organization working in the field of nature conservation and sustainable use of natural resources. It is involved in data gathering and analysis, research, field projects, advocacy, and education. IUCN's mission is to "influence, encourage and assist societies throughout the world to conserve nature and to ensure that any use of natural resources is equitable and ecologically sustainable". Over the past decades, IUCN has widened its focus beyond conservation ecology and now incorporates issues related to sustainable development in its projects. IUCN does not itself aim to mobilize the public in support of nature conservation. It tries to influence the actions of governments, business and other stakeholders by providing information and advice and through building partnerships. The organization is best known to the wide ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Baiji
The baiji (; IPA: ; ''Lipotes vexillifer'', ''Lipotes'' meaning "left behind" and ''vexillifer'' "flag bearer") is a possibly extinct species of freshwater dolphin native to the Yangtze river system in China. It is thought to be the first dolphin species driven to extinction due to the impact of humans. This dolphin is listed as “critically endangered: possibly extinct” by the IUCN, has not been seen in 20 years, and several surveys of the Yangtze have failed to find it. In China, the species is also called the Chinese river dolphin, Yangtze river dolphin, Yangtze dolphin and whitefin dolphin. Nicknamed the "Goddess of the Yangtze" (), it was regarded as the goddess of protection by local fishermen and boatmen. It is not to be confused with the Chinese white dolphin (''Sousa chinensis'') or the finless porpoise (''Neophocaena phocaenoides''). The baiji population declined drastically in decades as China industrialized and made heavy use of the river for fishing, transportati ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dolphin Drive Hunting
Dolphin drive hunting, also called dolphin drive fishing, is a method of hunting dolphins and occasionally other small cetaceans by driving them together with boats and then usually into a bay or onto a beach. Their escape is prevented by closing off the route to the open sea or ocean with boats and nets. Dolphins are hunted this way in several places around the world including the Solomon Islands, the Faroe Islands, Peru, and Japan which is the most well-known practitioner of the method. In large numbers dolphins are mostly hunted for their meat; some end up in dolphinariums. Despite the controversial nature of the hunt resulting in international criticism, and the possible health risk that the often polluted meat causes, tens of thousands of dolphins are caught in drive hunts each year. By country Faroe Islands Whaling in the Faroe Islands takes the form of beaching and slaughtering long-finned pilot whales. It has been practiced since about the time of the first Nor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Whaling
Whaling is the process of hunting of whales for their usable products such as meat and blubber, which can be turned into a type of oil that became increasingly important in the Industrial Revolution. It was practiced as an organized industry as early as 875 AD. By the 16th century, it had risen to be the principal industry in the Basque coastal regions of Spain and France. The industry spread throughout the world, and became increasingly profitable in terms of trade and resources. Some regions of the world's oceans, along the animals' migration routes, had a particularly dense whale population, and became the targets for large concentrations of whaling ships, and the industry continued to grow well into the 20th century. The depletion of some whale species to near extinction led to the banning of whaling in many countries by 1969, and to an international cessation of whaling as an industry in the late 1980s. The earliest known forms of whaling date to at least 3000 BC. Coas ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Non-human Person
Personhood or personality is the status of being a person. Defining personhood is a controversial topic in philosophy and law and is closely tied with legal and political concepts of citizenship, equality, and liberty. According to law, only a legal person (either a natural or a juridical person) has rights, protections, privileges, responsibilities, and legal liability. Personhood continues to be a topic of international debate and has been questioned critically during the abolition of human and nonhuman slavery, in debates about abortion and in fetal rights and/or reproductive rights, in animal rights activism, in theology and ontology, in ethical theory, and in debates about corporate personhood and the beginning of human personhood. Processes through which personhood is recognized socially and legally vary cross-culturally, demonstrating that notions of personhood are not universal. Anthropologist Beth Conklin has shown how personhood is tied to social relations among th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
American Association For The Advancement Of Science
The American Association for the Advancement of Science (AAAS) is an American international non-profit organization with the stated goals of promoting cooperation among scientists, defending scientific freedom, encouraging scientific responsibility, and supporting scientific education and science outreach for the betterment of all humanity. It is the world's largest general scientific society, with over 120,000 members, and is the publisher of the well-known scientific journal ''Science''. History Creation The American Association for the Advancement of Science was created on September 20, 1848, at the Academy of Natural Sciences in Philadelphia, Pennsylvania. It was a reformation of the Association of American Geologists and Naturalists. The society chose William Charles Redfield as their first president because he had proposed the most comprehensive plans for the organization. According to the first constitution which was agreed to at the September 20 meeting, the goal ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cetacean Intelligence
Cetacean intelligence is the cognitive ability of the infraorder Cetacea of mammals. This order includes whales, porpoises, and dolphins. Brain size Brain size was previously considered a major indicator of the intelligence of an animal. However, many other factors also affect intelligence, and recent discoveries concerning bird intelligence have called into question the influence of brain size. Since most of the brain is used for maintaining bodily functions, greater ratios of brain to body mass may increase the amount of brain mass available for more complex cognitive tasks. Allometric analysis indicates that in general, mammalian brain size scales at approximately the or exponent of body mass. Comparison of actual brain size with the size expected from allometry provides an encephalization quotient (EQ) that can be used as a more accurate indicator of an animal's intelligence. * Sperm whales (''Physeter macrocephalus'') have the largest known brain mass of any extant animal, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polygyny In Animals
Polygyny (; from Neo-Greek πολυγυνία, from πολύ- ''poly-'', "many", and γυνή ''gyne'', "woman" or "wife") is a mating system in which one male lives and mates with multiple females but each female only mates with a single male. Systems where several females mate with several males are defined either as promiscuity or polygynandry. Lek mating is frequently regarded as a form of polygyny, because one male mates with many females, but lek-based mating systems differ in that the male has no attachment to the females with whom he mates, and that mating females lack attachment to one another.Clutton-Brock T.H. (1989). ‘Review lecture: mammalian mating systems.' ''Proceedings of the Royal Society of London''. Series B, Biological Sciences 236: 339–372. Polygyny is typical of one-male, multi-female groupsBoyd, R., & Silk, J. B. (2009). How Humans Evolved (preferably the downloadable pdf version): WW Norton & Company, New York. and can be found in many species includin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pinnipeds
Pinnipeds (pronounced ), commonly known as seals, are a widely distributed and diverse clade of carnivorous, fin-footed, semiaquatic, mostly marine mammals. They comprise the extant families Odobenidae (whose only living member is the walrus), Otariidae (the eared seals: sea lions and fur seals), and Phocidae (the earless seals, or true seals). There are 34 extant species of pinnipeds, and more than 50 extinct species have been described from fossils. While seals were historically thought to have descended from two ancestral lines, molecular evidence supports them as a monophyletic lineage (descended from one ancestral line). Pinnipeds belong to the order Carnivora; their closest living relatives are musteloids (weasels, raccoons, skunks, and red pandas), having diverged about 50 million years ago. Seals range in size from the and Baikal seal to the and southern elephant seal male, which is also the largest member of the order Carnivora. Several species exhi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Orca
The orca or killer whale (''Orcinus orca'') is a toothed whale belonging to the oceanic dolphin family, of which it is the largest member. It is the only extant species in the genus '' Orcinus'' and is recognizable by its black-and-white patterned body. A cosmopolitan species, orcas can be found in all of the world's oceans in a variety of marine environments, from Arctic and Antarctic regions to tropical seas. Orcas have a diverse diet, although individual populations often specialize in particular types of prey. Some feed exclusively on fish, while others hunt marine mammals such as seals and other species of dolphin. They have been known to attack baleen whale calves, and even adult whales. Orcas are apex predators, as they have no natural predators. They are highly social; some populations are composed of very stable matrilineal family groups (pods) which are the most stable of any animal species. Their sophisticated hunting techniques and vocal behaviours, which ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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